Siricidae (Hymenoptera: Symphyta: Siricoidea) of the Western Hemisphere
Nathan M. Schiff1
,
Henri Goulet2*
,
David R. Smith3
,
Caroline Boudreault2
,
A. Dan Wilson1
,
Brian E. Scheffler4
1 USDA Forest Service, Southern Research Station, Center for Bottomland Hardwoods Research, Stoneville, MS 38776, USA nschiff@fs.fed.us
2 K. W. Neatby Building, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada henri.goulet@agr.gc.ca; boudreaultc@agr.gc.ca
3 Systematic Entomology Laboratory, PSI, Agricultural Research Service, U. S. Department of Agriculture, c/o National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, MRC 168, Washington, DC 20013-7012, USA sawfly2@aol.com
4 USDA Agricultural Research Service, USDA-ARS-CGRU, MSA Genomics Laboratory, 141 Experiment Station Rd., Stoneville, MS 38776, USA
*Corresponding author: henri.goulet@agr.gc.ca
Siricidae (Hymenoptera: Symphyta: Siricoidea) of the Western Hemisphere
Siricidae (Hymenoptera: Symphyta: Siricoidea) of the Western Hemisphere
Nathan M. Schiff1
,
Henri Goulet2*
,
David R. Smith3
,
Caroline Boudreault2
,
A. Dan Wilson1
,
Brian E. Scheffler4
1 USDA Forest Service, Southern Research Station, Center for Bottomland Hardwoods Research, Stoneville, MS 38776, USA nschiff@fs.fed.us
2 K. W. Neatby Building, 960 Carling Avenue, Ottawa, ON K1A 0C6, Canada henri.goulet@agr.gc.ca; boudreaultc@agr.gc.ca
3 Systematic Entomology Laboratory, PSI, Agricultural Research Service, U. S. Department of Agriculture, c/o National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, MRC 168, Washington, DC 20013-7012, USA sawfly2@aol.com
4 USDA Agricultural Research Service, USDA-ARS-CGRU, MSA Genomics Laboratory, 141 Experiment Station Rd., Stoneville, MS 38776, USA
*Corresponding author: henri.goulet@agr.gc.ca
Abstract
Horntails (Siricidae) are important wood–boring insects with 10 extant genera and about 122 species worldwide. Adults and larvae of Siricidae are often intercepted at ports and are of concern as potential alien invasive species.
The family consists of 7 genera and 33 species in the New World: Eriotremex with one species, Sirex with 14 species, Sirotremex with one species, Teredon with one species, Tremex with two species, Urocerus with seven species, and Xeris with seven species. Five of these species have been accidentally introduced from the Old World: Eriotremex formosanus (Matsumura, 1912) into southeastern United States, probably from Vietnam; Sirex noctilio Fabricius, 1793, an important pest of Pinus spp., into eastern North America, Argentina, Brazil, and Uruguay from central Europe; Urocerus gigas (Linnaeus, 1758) into Chile, probably from Europe; Urocerus sah (Mocsáry, 1881) into northeastern North America, probably from southern Europe or North Africa; and Tremex fuscicornis (Fabricius, 1783) into Chile, probably from China.
Six new species are described: Sirex abietinus; Goulet, n. sp.; S. hispaniola Goulet, n. sp.; S. mexicanus Smith, n. sp.; S. xerophilus Schiff, n. sp.; Xeris chiricahua Smith, n. sp.; and X. tropicalis Goulet, n. sp. Five species are reinstated: Urocerus caudatus Cresson, 1865, sp. rev.; U. nitidusT. W. Harris, 1841, sp. rev.; Sirex melancholicus Westwood, 1874, sp. rev.; S. obesus Bradley, 1913, sp. rev.; and S. torvus M. Harris, 1779,sp. rev. Eleven new synonyms are proposed: Neoxeris Saini and Singh, 1987, n. syn. of Xeris Costa, 1894; Sirex hirsutus Kirby, 1882, n. syn.of S. juvencus (Linnaeus, 1758); Urocerus zonatus Norton, 1869, n. syn. of S. nigricornis Fabricius, 1781; Sirex edwardsii Brullé, 1846, n. syn. ofS. nigricornis Fabricius, 1781; Sirex fulvocinctus Westwood, 1874, n. syn. of S. nigricornis Fabricius, 1781; Sirex abaddon Westwood, 1874, n. syn. of S. nigricornis Fabricius, 1781; Sirex hopkinsi Ashmead, 1898, n. syn. of S. nigricornis Fabricius, 1781; Sirex leseleuci Tournier, 1890, n. syn. of S. torvus M. Harris, 1779; Sirex duplex Shuckard, 1837, n. syn. of S. torvus M. Harris, 1779; Sirex latifasciata Westwood, 1874, n. syn. ofUrocerus albicornis (Fabricius, 1781); Xeris spectrum townesi Maa, 1949, n. syn. of X. indecisus (MacGillivray, 1893). Five new lectotypes are designated for: Paururus californicus Ashmead, 1904; P. pinicolus Ashmead, 1898; P. hopkinsi Ashmead, 1904; Sirex torvus M. Harris; and S. taxodii Ashmead 1904. Three changes in rank from subspecies to species level are proposed: Sirex californicus (Ashmead), n. stat., from S. juvencus californicus; Urocerus flavicornis (Fabricius), n. stat., from U. gigas flavicornis; and Xeris indecisus (MacGillivray), n. stat., from X. morrisoni indecisus. Two species are excluded from the New World Siricidae: Sirex juvencus (Linnaeus), and Xeris spectrum (Linnaeus); both species have been frequently intercepted in North America, but they are not established. One species is excluded from the Palaearctic Siricidae: Sirex cyaneus Fabricius. The European “Sirex cyaneus” is distinct from the American Sirex cyaneus; Sirex torvus M. Harris is the oldest name for this species.
We characterize the family based on all extant genera. The world genera are keyed and a reconstructed phylogeny is proposed. For genera not found in the New World, we provide a synonymic list, a description, and information about diversity with significant references. For genera in the New World, each genus includes the following (if available and/or pertinent): synonymic list, diagnostic combination, description for one or both sexes, taxonomic notes, biological notes, diversity and distribution, and references. Only New World Siricidae are treated at species level, each species includes the following (if available and/or pertinent): synonymic list, diagnosis, description of one or both sexes, geographical variation, taxonomic notes, origin of the specific epithet, biological notes, hosts and phenology (flight period data; a list of associated nematode and fungus species), and range.
DNA barcoding (cytochrome oxidase 1 – CO1) was shown to be a reliable identification tool for adults and larvae intercepted at ports. Larvae cannot be identified using classical morphological methods, but DNA barcoding can accurately distinguish larvae of all species tested to date. We include barcodes for 25 of the 33 New World species and consider in our taxonomic notes several Old World species as needed. DNA data has been most useful for confirming some morphologically similar species, associating specimens with two or three discrete color forms, and deciding the rank of some populations. The results have proved to be accurate and in agreement with species determined by classical morphological methods.
Tremex columba Photo by Henri Goulet
Introduction
In 2004, specimens of Sirex noctilio Fabricius were discovered in New York State (Hoebeke et al. 2005). The species is known to cause major damage to pine plantations in South America, South Africa, Australia and New Zealand. The news of its establishment in North America was taken seriously by Canadian and American authorities and major surveys were started (and are ongoing). Hundreds of sampling sites in United States from Michigan to New Hampshire and in Canada from the eastern region of Lake Superior to New Brunswick were visited weekly and Siricidae extracted from cut logs placed in rearing containers.
With this sudden interest in horntail wasps, taxonomists got involved because adults of S. noctilio are not obviously distinguishable from those of some of the native species in eastern North America. It was known that species close to S. noctilio belong to two species complexes, the cyaneus and californicus complexes, but further work was needed to resolve the taxonomic problems. Therefore, more or less independently, the first three authors concluded that the North American species required revision. N. M. Schiff studied mitochondrial DNA (cytochrome oxidase 1 – CO1) of most North American and central European species, and provided information about ecology, sampling techniques and associated fungi; H. Goulet studied the species and higher classification based mainly on morphological information, wrote the identification keys and checked several type specimens; and D. R. Smith prepared parts of the introduction and a section on specimens intercepted in North America, refined nomenclatural information, studied type specimens, prepared the reference section and was the main editor. C. Boudreault was responsible for statistics, illustrations, plate design and HTML programming for the web version.
Because Siricidae are large, usually showy insects, most collections have specimens, but because standard collecting methods rarely work to capture adults only a few collections have large numbers of specimens, obtained mostly by rearing. Malaise traps catch a few adults; sweeping and the use of yellow pan traps do not catch any. Adults are most easily collected by rearing from trunks of dead or dying trees. Adults of some species go to the top of hills (Chapman 1954), and if the vegetation is low enough they can be sampled with a net; others are attracted to fire in fire-prone forests and may be hand collected on trunks and stumps.
The 3000-4000 adults of Siricidae in the Canadian National Collection of Insects, Ottawa were almost entirely obtained by Canadian Forest Service staff. Over 70% of the specimens had been reared. This gave us good series of reared specimens from known hosts which greatly helped to resolve taxonomic problems in the Nearctic region. As the work progressed we decided to treat all Western Hemisphere species and world genera. We could not treat the world fauna at species level because most of the species are centered in Asia, a region poorly represented in North American collections.
Viitasaari (1984, 1988) and Midtgaard and Viitasaari (1989) provided us with the main clue to solving species complexes using adult morphology. In their works, ovipositor features were covered systematically. Amazingly, the ovipositor pits (very likely of S. noctilio not S. juvencus as stated) were illustrated much earlier (Hartig 1837), and females of almost every species of Sirex in the New World appear to have a unique set of ovipositor features. The character has not been as significantly useful at species level in other genera but each had a unique combination of other features. Other characters such as larvae (Hartig 1837, Yuasa 1922 [excellent illustrations of the larva of T. columba and many other structures]), male genitalia (Crompton 1919, Chrystal 1928), fine structures of the last tarsomere (Holway 1935), adult spiracles (Tonapi 1958), fore wing cenchrus coupling (Cooley 1896), internal thoracic musculature (Daly 1963), and larval digestive system (Maxwell 1955) were not studied by us. Larvae were not identified by us using morphology; instead, they were more easily and accurately identified using DNA barcodes.
Linnaeus (1758) described the first Siricidae, Sirex juvencus, Urocerus gigas and Xeris spectrum (originally as Ichneumon juvencus, I. gigas and I. spectrum) from the Old World. Sirex juvencus has been intercepted many times at North American ports. In the New World, the first valid species described was Tremex columba (Linnaeus 1763) (originally as Sirex columba), the first of 56 names proposed for our 28 native species. We summarize in 25-year periods the species names proposed and treated as valid here. From 1758–1775, three names were proposed; only T. columba is still in use. 1776–1800, five names were proposed; four are still in use, Sirex cyaneus Fabricius, S. nigricornis Fabricius, Urocerus albicornis (Fabricius) and U. flavicornis (Fabricius). From 1801–1825, two species names were proposed; neither is in use today. From 1826–1850, five names were proposed; Sirex nitidus (T. W. Harris) is in use. From 1851–1875, 17 taxa were proposed; seven species names are in use here, Sirex areolatus (Cresson), S. varipes Walker, Teredon cubensis (Norton), Urocerus californicus Norton, U. cressoni Norton, Xeris caudatus (Cresson), and X. melancholicus (Westwood). Norton and Cresson had good collections at their disposal and together they contributed 38% of the names in use here. From 1876–1900, 13 names were proposed; four are in use here, Sirex behrensii (Cresson), Xeris indecisus (MacGillivray), X. morrisoni (Cresson), and X. tarsalis (Cresson). From 1901–1925, eight species names were proposed; three are in use here, Sirex californicus (Ashmead), S. obesus Bradley, and Urocerus taxodii (Ashmead). By the end of this period, 90% of the named New World species were known. From 1926–1950, two names were proposed; one, Sirex longicauda Middlekauff, is in use here. From 1951–1975, no names were proposed. From 1976–2000, one name was proposed and is still in use; Sirotremex flammeus Smith.
In summary, Cresson proposed nine names, Westwood eight, Ashmead five, Fabricius four, and Kirby four. Of the names proposed by Cresson 67% are valid, by Westwood 12%, by Ashmead 40%, by Fabricius 100%, and by Kirby 0%. The best contributors of valid names are Linnaeus, Fabricius, Walker, Middlekauff, and Smith with 100% success, and Cresson and Norton with 67% success. These seven authors described 76% of the names in use today. Of the 56 species proposed, 22 are still in use in this paper. In this work we add six new species bringing the total number of native species to 28.
Methods & Materials
We based this study on more than 12000 specimens. Most specimens are preserved in collections, but many (over 3000 specimens) were part of surveys conducted in eastern Canada and south of the Great Lakes in the United States following the establishment of Sirex noctilio Fabricius. Most of these specimens were not retained. The following is a list of collections with their respective curators.
| AEI | American Entomological Institute, Gainesville, FL, USA. D. Wahl. |
| AMNH | Department of Entomology Collection, American Museum of Natural History, New York, NY, USA. R. T. Schuh. |
| ANSP | Academy of Natural Sciences, Philadelphia, PA, USA. J. Weintraub. |
| BDUC | Biology Department, University of Calgary, Calgary, AB, Canada. R. Longair. |
| BMNH | Department of Entomology, The Natural History Museum, London, England. C. Gillette. |
| BYUC | Brigham Young University, Provo, UT, USA. S. M. Clark. |
| CASC | Department of Entomology, California Academy of Sciences, Golden Gate Park, San Francisco, CA, USA. W. J. Pulawski. |
| CASS | Agriculture and Agri–Food Research Centre, Saskatoon, SK, Canada. |
| CFIA | Canadian Food Inspection Agency, Ottawa, Ontario, Canada. H. Douglas. |
| CNC | Canadian National Collection of Insects and Arachnids, Ottawa, ON, Canada. H. Goulet. |
| CUCC | Clemson University Arthropod Collection, Clemson University, Clemson, SC, USA. J. C. Morse. |
| CUIC | Cornell University Insect Collection, Department of Entomology, Cornell University, Ithaca, NY, USA. E. R. Hoebeke. |
| DABH | Department of Applied Biology, University of Helsinki, Helsinki, Finland. M. Viitasaari. |
| DEBU | Department of Environmental Biology, University of Guelph, ON, Canada. S. A. Marshall & S. Paiero. |
| DENH | University of New Hampshire Insect Collection, Department of Entomology, University of New Hampshire, Durham, NH, USA. D. S. Chandler. |
| EDUM | Entomology Department, University of Manitoba, Winnipeg, MB, Canada. †R. E. Roughley. |
| EIHU | Entomological Institute, Faculty of Agriculture, Hokkaido University, Sapporo, Japan. |
| FRLC | Atlantic Forestry Centre, Natural Resources Canada, Fredericton NB, Canada. J. Sweeney. |
| FRNZ | Scion – next generation biomaterials, Te Papa Tipu Innovation Park, Rotorua, New Zealand. S. Sopow. |
| FSCA | Florida State Collection of Arthropods, Division of Plant Industry, Gainesville, FL, USA. J. Wiley. |
| GLFC | Great Lake Forest Centre, Natural Resources Canada, Sault Ste. Marie, ON, Canada. K. Nystrom. |
| HMUG | Hunterian Museum, Department of Zoology, University of Glasgow, Glasgow, Scotland. G. Hancock. |
| HNHM | Zoological Department, Hungarian Natural History Museum, Budapest, Hungary. |
| ICCM | Section of Insects and Spiders, Carnegie Museum of Natural History, Pittsburgh, PA, USA. J. E. Rawlins. |
| IES | Instituto de Ecología y Sistemática, La Habana, Cuba |
| INHS | Insect Collection, Illinois Natural History Survey, Champaign, IL, USA. |
| LECQ | Laurentian Forestry Centre, Natural Resource Canada, Ste. Foy, QC, Canada. I. Klimaszewski. |
| LEMQ | Lyman Entomological Museum and Research Laboratory, MacDonald College, McGill University, Ste. Anne de Bellevue, QC, Canada. T. A. Wheeler. |
| LSUK | Linnean Society, Burlington House, Piccadily, London, England. |
| MCZC | Entomology Department, Museum of Comparative Zoology, Harvard University, Cambridge, MA, USA. E. O. Wilson. |
| MTEC | Department of Entomology, Montana State University, Bozeman, MT, U.S.A. M. A. Ivie. |
| MHND | Museo Nacional de Historia Natural, Plaza de Cultura, Santo Domingo, Dominican Republic. C. Suriel. |
| MNHN | Muséum National d’Histoire Naturelle, Paris, France. C. Villemant. |
| MRNQ | Ministère des Ressources Naturelles, Direction de l’Environnement et de la Protection des Forêts, Service des Relevés et des Diagnostics, Québec, QC, Canada. C. Piché. |
| NCSU | North Carolina State University Insect Collection, Department of Entomology, North Carolina State University, Raleigh, NC, USA. |
| NFRC | Northern Forestry Centre, Natural Resource Canada, Northwest Region, Edmonton, AB, Canada. G. Pohl. |
| NFRN | Atlantic Forestry Centre, Corner Brook, NL, Canada. P. Bruce. |
| NSMT | Entomological Collection, National Science Museum (Natural History), Tokyo, Japan. A. Shinohara. |
| NZAC | New Zealand Arthropod Collection, Landcare Research, Auckland, New Zealand. D. Ward. |
| OSAC | Oregon State Arthropod Collection, Department of Zoology, Oregon State University, Corvallis, OR, USA. C. Marshall. |
| OXUM | Hope Entomological Collections, University Museum, Oxford, England. J. E. Hogan. |
| PANZ | Ministry of Agriculture and Forestry, Biosecurity New Zealand, Plant Health & Environment Laboratory, Auckland, New Zealand. O. Green. |
| PFRC | Pacific Forestry Centre, Natural Resource Canada, Victoria, BC, Canada. L. Humble. |
| ROME | Department of Entomology, Royal Ontario Museum, Toronto, ON, Canada. C. Darling. |
| SDEI | Deutsches Entomologisches Institut, Senckenberg, Germany. A. Taeger and S. M. Blank. |
| UAIC | Department of Entomology Collection, University of Arizona, Tucson, AZ, USA. D. Madison. |
| UAM | University of Alaska Museum, Fairbanks, AK, USA. D. Sikes. |
| UAMC | Universidad Autonoma de Morelos, Cuernavaca, Mexico. |
| UASM | Department of Zoology, Strickland Entomological Museum, University of Alberta, Edmonton, AB, Canada. D. Shpeley. |
| ULQC | Insect Collection, Department of Biology, Laval University, Quebec, QC, Canada. J. M. Perron. |
| UCRC | University of California, Riverside, CA, USA. D. Yanega. |
| USBD | Biology Department, University of Saskatchewan, Saskatoon, SK, Canada. |
| USFS-AK | USDA Forest Service, State and Private Forestry, Forest Health Protection, Fairbanks Unit, Fairbanks, AK. J. J. Kruze. |
| USFS-GA | USDA Forest Service, Southern Research Station, Athens GA, USA. D. Miller. |
| USFS-MS | USDA Forest Service, Stoneville, MS, USA. N. M. Schiff. |
| USNM | National Museum of Natural History, Smithsonian Institution, Washington, DC, USA. D.R. Smith. |
| ZMUC | Department of Entomology, Zoological Museum, University of Copenhagen, Universitetsparken, Copenhagen, Denmark. L. Vilhelmsen. |
Materials for DNA studies
Collection of samples: Woodwasps for the DNA analysis portion of this study were collected by numerous collaborators or the authors using 3 different methods. They were netted or hand-collected, especially at forest fires; reared from host material; or collected in Lindgren funnel or panel traps baited with terpenes and/or ethanol. The trapped specimens were mostly collected as by-products of bark beetle trapping programs. Specimens were frozen, preserved directly in 70%-95% ethanol or collected into diluted ethylene glycol or similar preservative and then transferred to 70%-95% ethanol. Specimens were accumulated at the USFS–MS, CNC, and PFRC for DNA analysis.
Methods for morphological studies
Most specimens were studied and images taken with a MZ16 Leica binocular microscope and an attached Leica DFC420 digital camera. Some specimens were photographed using a DSLR Canon Rebel Xti camera with a 100 mm macro lens. Multiple images through the focal plane were taken of a structure and these combined using Combine ZM or ZP designed by Alan Hadley to produce a single, focused image. Specimens were illuminated with a 13 watt daylight fluorescent lamp.
Methods for DNA studies
DNA Isolation. DNA was isolated, amplified and sequenced both in Guelph and Stoneville, MS. DNA from specimens from Ottawa and Victoria were sequenced in the Biodiversity Institute of Ontario, Guelph, ON, according to standard protocols (as detailed in Fernandez-Triana et al. 2011). Protocols used in Stoneville were as follows. Tissue for extraction was collected from the thorax either by pulling off a hind leg and collecting the muscle tissue still attached to the coxa or by digging tissue directly from the thorax with a pair of forceps. Genomic DNA was isolated from the tissue using either a slightly modified Quiagen DNeasy spin-column protocol for animal tissues or the Masterpure™ Yeast DNA Purification kit by Epicentre (Madison, WI). We modified the DNeasy spin–column protocol by changing the conditions of the proteinase K incubation from 1–3 hrs at 56° C to 1 hr at 70° C and by changing the final elution solution from 200μl Buffer AE to 50μl Buffer AE plus 200μl Ambion nuclease free water. In all extractions, care was taken to avoid digestive tract tissue and eggs which might contain microbial contaminants such as Wohlbachia sp. Early in the study, a Wohlbachia species was sequenced from a woodwasp but not from a species used in this study. We have sequenced more than 1000 woodwasps (leg or thorax tissue) since then with no further discovery of Wohlbachia.
Amplification and clean up. Over the course of the study several PCR reaction amplification protocols were used successfully. The most evolved and preferred protocol is very similar to that used by Roe et al. (2006). PCR reactions containing 10μl of DNA template, 9μl of Ambion nuclease free water, 2.5 μl Advantage 2 10X buffer (Clontech, Mountain View, CA), 2 μl of each oligo (each at 10mM), 1.5 μl of dNTP mix (each at 10mM) and 0.4 μl of Advantage 2 Taq, were amplified in a PTC-100 Programmable Thermal Controller (M. J. Research Inc.) as follows; an initial denaturation step at 94°C for 2 minutes followed by 35 cycles of 94°C for 30 seconds, 45°C for 30 seconds and 68°C for 2 minutes, followed by a final extension at 68°C for 10 minutes. The extension steps were at 68°C rather than 72°C because Advantage 2 Taq is more efficient at the lower temperature (Manufacturer’s instructions). The oligos used were LCO1490: 5’-ggtcaacaaatcataaagatattgg-3’and HCO2198: 5’-taaacttcagggtgaccaaaaaatca-3’of Folmer et al. (1994) where the numbers refer to the position of the Drosophila yakuba 5’ nucleotide. PCR Products were visualized on 30% acrylamide/bis gels (mini Protean II electrophoresis cell by BioRad) stained with either ethidium bromide or preferably EZ-Vision 2 (N650-Kit by Amresco Inc.). PCR products were cleaned using an Exo-SAP protocol. Up to 20 μl of PCR product was mixed with 8μl of Exo-SAP (2μl Exonuclease I at 10U/μl, USB product no. 70073Z, Cleveland, OH; 20 μl Shrimp Alkaline Phosphatase at 1U/μl USB product no. 70092Z, Cleveland, OH; 78 μl ddH2O) and heated to 37°C for one hour followed by 15 minutes at 80°C.
Sequencing. Double stranded PCR products (at least 20ng/μl) were sequenced on an ABI 3730xl sequencer (Applied Biosystems, Foster City, CA) using BigDye 3.1 in 10μl reactions (1.75μl 5X sequencing buffer, 0.5 μl BigDye 3.1, 0.8 μl 10 μM primer, at least 20 ng DNA template and water up to 10 μl). DNA template was quantified by comparison to Low DNA Mass Ladder (Invitrogen cat. No. 10068-013, Carlsbad, CA), at least 1 μl of template was used even if the concentration of DNA appeared to be significantly greater than 20 ng/μl. The cycle sequencing reaction was 2 minutes at 96°C followed by 25 cycles of 96°C for 30 seconds, 50 °C for one minute and 60°C for 4 minutes. The sequencing reaction (10μl) was stopped by addition of 2.5 μl 0.125 M EDTA (pH 8.0) followed by centrifugation at 4000 rpm for one minute. The products were precipitated for 30 minutes in the dark by addition of 30μl of 100% ethanol followed by centrifugation at 4000 rpm for 30 min at 4°C. The samples were washed with 100μl of 70% ethanol spun for 15 minutes at 1650 rpm for 15 minutes and then air-dried in the dark for 15 minutes. Dried products were stored at -20°C until injection. Products were re-upped in 100μl of deionized water, centrifuged at 4000 rpm for 2 minutes and injected immediately into the sequencer using the ABI default injection module appropriate for the installed capillary array, but decreasing the injection time to 2 sec.
Data Manipulation. Sequences were captured using Data Collection Software v3.0 with Dye set Z_BigDyeV3 from Applied Biosystems which gave us ab1. sequence trace files and seq. sequence text files. Templates were sequenced in both directions and the corresponding sequences were paired into individual specimen contigs using Lasergene Seqman by DNAStar. To obtain full length sequences it was sometimes necessary to sequence individual specimens several times and combine the partial sequences to form the final sequence used for analysis. Individual specimen contigs were aligned using Clustal V, and built into trees (Neighbor Joining) (Saitou and Nei 1987) using Megalign also by DNAStar.
Exclusion of Numts and Heteroplasmy. Two of the potential pitfalls of using mitochondrial sequences for identification include mistakenly sequencing nuclear pseudogenes of mitochondrial origin (NUMTs), or obtaining multiple sequences from heteroplasmic individuals. To reduce the risk of NUMTs we were careful to select only muscle (mitochondrial rich) tissue from specimens and all sequences were translated and inspected for stop codons and insertions and deletions (characteristics of pseudogenes). To date, all siricid sequences have been free of stop codons, insertions and deletions. Heteroplasmy is when an individual has more than one mitochondrial haplotype (sequence). To reduce possible variation due to heteroplasmy we sequenced double stranded PCR products directly rather than sequencing clones. If there were rare alternate haplotypes they would be masked by the most common haplotype. We further sequenced many individuals multiple times with no variation (data not shown).
Methods for active collecting, trapping and rearing Siricidae
Although siricids are large and colorful insects, they are not commonly encountered in general collecting in forests and more specialized techniques are often used to obtain them. These methods fall into three general categories: collecting in specific habitats based on knowledge of siricid behavior, trapping using a variety of different traps, and rearing from infested wood. With the recent discovery of Sirex noctilio in North America (Hoebeke et al. 2005, deGroot et al. 2006) there has been increased interest in surveys for S. noctilio and other siricids and the techniques below are evaluated in light of their utility for survey work.
Active collecting. Like many wood-boring insects, S. noctilio and presumably other siricids are attracted to the volatiles produced by wounded, stressed or dying trees (Madden 1971, Newmann et al. 1982). In some circumstances a single, cut tree can be attractive. NMS and Paul Lago collected more than 100 specimens of S. nigricornis and many other wood borers and parasitoids over a 3-day period in October, 2001, on a single loblolly pine (DBH approximately 30 cm) that was cut into approximately 50 cm bolts at a semi rural-setting in Oxford, Mississippi. Unfortunately, this was a rare occurrence; NMS has attended many freshly cut trees that were not visited by siricids. Presumably, in Oxford, there was a local population of recently emerged S. nigricornis and the cut loblolly pine was the only local source of volatiles.
Most often, siricids are attracted to areas where there are many wounded trees. In Western North America, siricids are commonly found at forest fires. Males form mating aggregations high up on unburned trees at the edge of forest fires and females can be found ovipositing into freshly burned stumps or trees (Middlekauf 1960, Middlekauf 1962, Westcott 1971, Schiff unpublished data). Larvae can develop in the fire-killed trees and adults sometimes emerge from houses built with salvaged lumber (Middlekauf 1962, Lynn Kimsey personal communication). Siricids are also found at logging decks and at mills where the cut trees presumably release attractive volatiles (Wickman 1964, Wood Johnson personal communication). Siricids can be surveyed at fires and mills but these are not always located in the study area of interest.
Siricids are also known to “hill-top”. Males and females of many widely dispersed insect species find mates at prominent landscape features like the tops of hills. Typically, there are more males than females and the host plants do need to be present as the females can fly to the host after mating. “Hilltopping” is probably much more common than has been reported because it is unusual to find a hill top with short vegetation where it can be observed (for general information, see Skevington (2008)). Similar behaviour has also been noted on fire towers. Specimens of Urocerus sah and Xeris melancholichus were collected over several years at the top of Mount Rigaud in eastern Canada (Fig. A2.1). At the same site, males of many species of Diptera, Lepidoptera, other Hymenoptera and Coleoptera were observed in similar aggregations. Among Hymenoptera, males of Xiphydria spp., Trichiosoma triangulum Kirby and Cimbex americana Leach were commonly collected with only occasional females being collected. This phenomenon is widespread. J. O’Hara, a dipterist, collected many males of Sirex obesus Bradley on hill tops in Arizona and New Mexico, Chapman (1954) recorded numerous males of Urocerus flavicornis on a mountain top in western Montana, and Jennings and Austin collected or recorded nine males of Austrocyrta fasciculata Jennings and Austin (Xiphydriidae) aggregating on top of Mount Moffatt and Mount Rugged in Queensland, Australia (Jennings et al. 2009).
Trapping. Siricids are most commonly collected by three trapping methods: 1) flight intercept trapping, 2) using artificial tree-mimicking traps baited with a chemical lure and 3) using trap or lure trees.
- The most commonly used flight intercept trap is the Townes style Malaise trap (Townes 1972). Although Malaise style traps were designed to catch Hymenoptera, including Symphyta, they only occasionally catch siricids (Smith and Schiff 2002) and are generally considered to be too expensive to use for siricid surveys.
- The use of artificial tree-mimicking traps with lures for siricids is largely a byproduct of bark beetle trapping programs. In fact, the discovery of S. noctilio in the United States resulted from the identification of a siricid caught in an exotic bark beetle survey funnel trap (Hoebeke et al. 2005). Almost all the survey work since the discovery of S. noctilio in North America has used artificial traps. The traps most commonly used are the Lindgren multiple-funnel trap and the cheaper cross-vane trap (Figs. A2.2 and A2.3). In silhouette, the traps mimic tree trunks and both use liquid filled collecting vessels. Typically the traps are baited with lures that mimic host volatiles of a wounded tree, namely a combination of monoterpenes and/or ethanol. These traps are relatively cheap and easy to assemble and service but like the Malaise trap they are not particularly efficient. In a 1999 study of five types of traps, 1661 siricids were collected over 5300 trap days for a trapping rate of approximately one siricid every three days. Presumably these are optimal results because the traps were located around a mill considered to be a wood-borer rich environment (McIntosh et al. 2001). The relatively low efficiency of these traps may be a function of the type of lure. These baited traps likely compete with all the stressed or damaged trees in the area, which reduces their effectiveness. Presumably trapping would be more efficient if the traps were baited with specific sex pheromone lures but none have been identified for Siricidae to date although components of contact sex pheromones for S. noctilio have recently been reported (Böröczky et al. 2009). An anomaly of artificial traps is that they seldom catch male siricids. We believe this is because traps are normally positioned with the top approximately two meters from the ground to facilitate collecting samples and male siricids spend most of their time in tree tops.
- Originally, “trap” trees were used as a means to detect the presence of S. noctilio in Southern Hemisphere Pinus radiata plantations. Selected trees that were mechanically wounded were found to be attractive to S. noctilio, depending on the season and degree of wounding. Felled trees were attractive immediately but only susceptible to attack for about 2 weeks whereas girdled trees were not attractive for 9–12 days but remained attractive for a season or more (Madden 1971, Madden and Irvine 1971). The method was later refined by switching to use of a chemical herbicide instead of mechanical wounding (Morgan and Stewart 1972, Minko 1981, Newmann et al. 1982) and the trap trees evolved into a delivery system for parasitic nematodes as well as a means of detecting S. noctilio. Once the wounded trap tree was infested with S. noctilio, it would be felled and inoculated with nematodes. The nematodes would attack the larvae and be distributed when the adult woodwasps emerged. In the northern United States, the suitability and attractiveness of trap trees for S. noctilio is dependent on timing of herbicide injection and host tree species (Zylstra et al. 2010). Although this is the preferred method for detecting S. noctilio and delivering the parasitic nematode to control infestations in the Southern Hemisphere, it is labor intensive for survey work and requires landowner consent to wound trees. As far as we know trap tree methods have not been developed for any native species.
Rearing. Perhaps the best way to collect siricids is by rearing them from infested logs. The advantages of this method are that males are often reared along with females, the host tree can often be positively identified, and living specimens can be obtained for biological studies. This method can also be proactive. Specimens of Urocerus taxodii for this study were reared by wounding three bald cypress trees in the Delta National Forest, Sharkey Co., Mississippi, waiting for them to be attacked and later caging 1.5 meter bolts from the trees at the USFS–MS. Many other specimens in this study were also reared from wounded trees as part of a decade long Canadian Forest Service wood borer survey (as in Figs. A2.4, A2.5 and A2.6). Disadvantages include difficulty finding suitably infested trees and the space and time required for rearing. NMS has found siricid-infested trees by following siricid specific parasitoids like the giant ichneumonid wasps Megarhyssa spp., and looking for siricid damage such as perfectly round emergence holes. In some cases, after multiple drillings, female siricids and/or Megarhyssa can no longer withdraw their ovipositors and they become stuck and die. Ants or birds dispose of the bodies but the ovipositors sometimes remain protruding from the wood, indicating siricid infested trees (Spradberry and Kirk 1978, Schiff, unpublished data). Another clue is to look for the characteristic brown staining in cut timber resulting from the symbiotic fungus, Amylostereum sp. (Spradberry and Kirk 1978, Tabata and Abe 1997).
Morphology
Structural terms
The following is intended as an overview of adult siricid structure wherein terms used in this work are defined and illustrated. Terms for structures mostly follow Huber and Sharkey (1993), but a few terms are specific to sawflies and Siricidae. English terms are used for the female genitalia for which the numerous figures in Ross (1937) were consulted. The terms used by Wong (1963) are also given in parenthesis.
The body consists of three distinct sections: the head, thorax and abdomen (lateral habitus of female Fig. A3.1 and lateral habitus of male Fig. A3.2).
The head consists of the head capsule, eye, antenna, and mouthparts (Fig. A3.1).
Head capsule. The head capsule is divided into several regions that usually have indistinct boundaries. In frontal view the clypeus is the region below and between the antennal sockets (Fig. A3.4). The face is the region lateral to the clypeus ventral to the antennal sockets which is mostly composed of the antennal scrobe (Fig. A3.4), a depression that receives the antennal scape when it is appressed to the head. The frons is the region between the inner edges of the eyes between the ventral edges of the antennal sockets and median ocellus (Fig. A3.4). The vertex is the region between the ventral margin of the median ocellus and highest part of the head capsule, which above the eyes in dorsal view extends laterally to about outer margin of each eye (Figs. A3.4, A3.6). The vertex has three ocelli, the median ocellus, and two lateral ocelli, but most Siricidae lack the clearly differentiated postocellar furrow behind each lateral ocellus that is more apparent in most other sawflies. The gena (often referred to as temple) is the surface posterior to the eye in lateral view, including the surface below the eye (Fig. A3.5). Although the occiput is not clearly differentiated from the gena and vertex it is considered as the posterior surface of the head capsule (Figs. A3.5, A3.6). The occiput surrounds the foramen magnum (an opening between the head and the thorax) and meets ventrally along the occipital junction.
Antenna. The antenna is divided into three principal sections, the scape, pedicel and flagellum. Little is described in the work for the first two sections but various character states of the flagellum are described. The flagellum consists of 4 to about 30 flagellomeres that are numbered consecutively following the pedicel (Fig. A3.11).
Mouth parts. The labrum is a very small, finger–like structure that is normally concealed under the clypeus between the mandibles. The labial palp (Fig. A3.5), though very short, consists of two or three palpomeres that are clearly visible below the mandible. The maxillary palp consists of a single palpomere that is hidden under other mouth parts.
The thorax consists of three major sections, the prothorax, mesothorax and metathorax, including the wings and the legs.
Prothorax (Figs. A3.1, A3.3). The prothorax is the anterior segment of the thorax. It consists of a dorsal, transverse sclerite, the pronotum, that laterally extends ventrally toward the procoxae. On either side ventral to the pronotum is the propleuron. The prothorax lacks wings but bears a pair of fore legs.
Mesothorax (Figs. A3.1, A3.3). The mesothorax is the middle segment of the thorax. The dorsal sclerite, the mesonotum is divided by the transscutal fissure (we are not certain that the broad furrow is really this structure seen in later Hymenoptera lineages, but its starting and ending point match) into an anterior mesoscutum and posterior axilla and mesoscutellum. The lateral surface of the mesothorax is the mesopleuron, which is differentiated into an anterior mesepisternum and posterior mesepimeron. The mesothorax has a pair of fore wings and a pair of mid legs.
Metathorax (Figs. A3.1, A3.3). The metathorax is the posterior segment of the thorax. The dorsal sclerite of the metathorax, the metanotum, bears a pad, the cenchrus, anterolaterally (Fig. A3.3). The lateral surface of the metathorax, the metepisternum and metepimeron, are not referred to in this work except for color patterns. The metathorax has a pair of hind wings, and a pair of hind legs.
Wings. The characteristic wing cells and veins of the fore and hind wings are illustrated in Figs. A3.29 & A3.30. One of the most striking features of Siricidae is what appears to be incredible variation in wing venation, including the appearance or the disappearance of veins symmetrically or asymmetrically on either wing. Such variation is very rarely seen in other Hymenoptera, a group where wing veins are important for classification. Habitus images in Schiff et al. (2006) provide many examples of variation in siricid wing venation and although this was not their intended goal, it is easy to observe the venation anomalies among the nicely spread specimens. Some veins of Siricidae are considered as part of the ground plan of the Hymenoptera such as the basal portion of vein 2A and the presence of fore wing vein cu1. The tendency for veins to appear or disappear in Siricidae might suggest atavisms, i.e., reactivation of long lost character states or a reversal to an ancestral state but we are more tempted to view the feature as newly created within the Siricidae. For example, we have seen specimens with a partial cross vein found basal to vein cu1, for which there is no equivalent in other Hymenoptera. Despite the exceptional variation in veins of Siricidae, we have used wing venation in keys to subfamily and genera. However, where possible we supplement these wing characters with others features not associated with wings.
Legs (Figs. A3.1 and A3.2). Each leg consists of five sections, the coxa, trochanter, femur, tibia and tarsus. This last section, the tarsus, consists of five tarsomeres that are numbered consecutively from the tibia. The prefixes “pro”, “meso” or “meta” are used to indicate which thoracic segment each leg segment belongs (see hind leg in Fig. A3.2). The tarsal pads (pulvillus/pulvilli), also known as plantulae (Schulmeister 2003), are membranous surfaces ventrally on tarsomeres 1-4 (Figs. A3.27 & A3.28) that are white and convex, and extend very slightly anterior to the apical margin of the tarsomeres (Schulmeister, 2003). In some species, the tarsal pads are relatively short (Fig. A3.28). The tarsal pads can best be observed on metatarsomere 2 because the tarsi of the fore and mid legs are often folded close to the body and the tarsal pads are then hidden. Observation of the tarsal pads is important for identification and is usually easy unless the specimen is covered with oil. A fine paint brush moistened with 95% ethanol can be used to help remove oil.
The abdomen consists of several segments that are numbered consecutively following the thorax. Tergum 1 (first abdominal tergum, Fig. A3.3) has a deep longitudinal cleft medially, it is not fused to the metapleuron laterally and although it is fused dorsally to the thorax it is separated from it by a deep furrow along its anterior edge. Structure of the abdomen of males and females otherwise differs and for this reason they are discussed separately below.
The female abdomen has ten terga (singular: tergum) dorsally and seven sterna (singular: sternum) ventrally (Fig. A3.7), of which terga 8-10 are conspicuously modified. Tergum 8 is greatly enlarged and is extended posteriorly. Tergum 9 is the largest tergum and has a deeply impressed dorsomedial impression, the median basin (Fig. A3.3), also known as the precornal basin. The lateral edges of the median basin are sharply outlined only near its base to almost to the posterior edge of tergum 9 (Fig. A3.12). The anterior edge of the basin, when visible, is ridge–like and its lateral limits are outlined by two slightly convergent furrows. The maximum width of the basin at its base is measured between the outer furrows, which are usually outlined in black. The posterior edge of the basin is a furrow between terga 9 and 10, which is often interrupted medially in specimens of Sirex. Tergum 10 is modified as a sharp horn–like projection, the cornus. The cornus varies in shape, but its apex forms a short tube (Fig. A3.9) that probably assists adult movement in their larval host tunnels.
The abdomen posterior to sternum 7 has an ovipositor that is covered by two sheaths when not in use.
- Each sheath consists of three parts: a basal small sclerite dorsobasally (valvifer 1), a long basoventral sclerite (valvifer 2), and an apical sclerite (valvula 3). In this work only the last two sclerites are referred to, as basal section and apical section of the sheath (Fig. A3.26). The length of these two sections is compared to one another and to the fore wing length.
- The ovipositor consists of a fused pair of dorsal lances (valvula 2) and a pair of ventral lancets (valvula 1) (Figs. A3.16 & A3.17). The lance and lancet slide along each other and help move the egg along the ovipositor as well as drilling in wood and removing the resulting sawdust for egg deposition. The part described in this work is the lancet, which is divided in numerous sections that we called annuli. Lancet annuli usually are outlined by vertical to slanted ridges (Fig. A3.17). The annuli are usually present to the base of the lancet, but in some species several basal annuli are difficult to distinguish because each annulus is barely outlined dorsally near the lance. The number of annuli varies within species and between species. The apex of the lancet consists of four annuli each with a large tooth (Fig. A3.17). Some or all of the annuli, anterior to these four apical annuli, have a pit adjacent to the line or ridge of the annulus (Fig. A3.17). The size of the pit varies from 0.1-0.7 times the length of the annulus (Figs. A3.18 – A3.21), but regardless of whether small or large the pits may gradually become markedly smaller anteriorly or even disappear suddenly or gradually toward the base. The pits may also be wide to narrow, from 2.5-1.0 times as long as high (Figs. A3.18-A3.21). To photograph the lancet for the best range of tonalities, we oriented it toward the light. Therefore contrary to normal, we present images of the ovipositor in lateral view but with the lancet at the top rather than at the bottom of the image. This view is most similar to what will be seen by users when viewing a female abdomen in lateral view with the ventral surface facing away from the user (toward the top of the page in most of our images).
The male abdomen has eight terga dorsally and nine sterna ventrally (Fig. A3.8). Tergum 8 is slightly longer than the preceding segments. The posterior edge of sternum 8 is narrowly or widely concave and sternum 9 is extended posteriorly as a horn or cornus. The lateral portion of the genitalia (the harpes) is usually visible between tergum 8 and sternum 9, but this was not studied here. In addition to structural terms for body parts, some terms designate surface features, such as ridges (plural carinae, singular carina), furrows (plural sulci, singular sulcus), pits (punctures) and microsculpture. The meaning of ridges and furrows are clear but pits and microsculpture require more discussion.
- Pits are concave impressions consisting of multiple cell. Each pit is usually associated with a sensory cell, which in most pits of Siricidae is a seta or seta-like mechanoreceptor. We use the word “pit” rather than the more common expression “puncture” because it refers to a concave impression not a hole through the cuticle. Pit sizes are compared to the maximum diameter of a lateral ocellus (e.g., for a small pit, the diameter may be 0.1 times the diameter of a lateral ocellus whereas for a large pit it may be 0.5 times times the lateral ocellus diameter), and the density is expressed as the number of typical pit diameters between pits (Figs. A3.22 & A3.23). Pits in Siricidae are usually simple concave and round impressions, but those on the mesoscutum and mesoscutellum may be very dense and polygonal with their edges becoming ridges of various heights so as to look like irregular craters or a fish net (Fig. A3.24). An unusual type of pit in Siricidae is the “pegged pit”, which is found on at least the ventral surface of most flagellomeres (Fig. A3.25). Each pegged pit has a sensory cell.
- Microsculpture consists of small cellular imprints on the cuticle within which there is no sensory cell. Typical microsculpture of insects is roughly hexagonal. The edge of a cellular imprint is almost always outlined by sharp furrows that forms a net– or mesh–like pattern resembling a fishing net. The surface area delimited by the furrows or meshes is called a “sculpticell” (Allen and Ball, 1980). A sculpticell surface may be flat, concave or pit–like (Fig. A3.13), convex, scale–like (i.e., surface is raised along the posterior or apical edge) (Fig. A3.14), or even seta–like. Each sculpticell is normally completely outlined by meshes but sometimes one or more sculpticells can be fused (Fig. A3.15). Sculpticells can also be stretched laterally (e.g., transverse meshes may be 2-4 times as wide as long), or longitudinally (an uncommon feature).
- Microsculpture is best observed at magnifications above 50 times under diffuse light. To reduce glare a translucent piece of plastic (e.g., tracing acetate) should be positioned between the light source and specimen about 20 mm from the specimen. A 13–watt daylight fluorescent light source also gives very good results.
Size is one variable that affects all structures of a specimen, but which normally is not analyzed or discussed in detail. Size range within well sampled siricid species is great. For example, both sexes of S. noctilio may range between 8 and 36 mm and similar size variation is true for many other species studied. One effect of body size is pit size. Because the taxonomically most significant pits are on the head, the size of pits is stated in relation to a nearby reference point, the diameter of the lateral ocellus. Pit density is also affected by specimen size, often being denser in larger than in smaller specimens of a species. Although the shape of the female cornus does not vary with size for most species (e.g., in S. nigricornis, it remains angular in lateral view for all sizes) in S. californicus the edge of the cornus is convex in the largest females, whereas it is straight in medium size females, and angular in small females.
Measurements
When possible, 30 specimens of each sex were measured. Means and standard deviations were calculated using Microsoft Excel software. The main measurements are the length of the basal and apical sections of the ovipositor sheath and the maximum length of the fore wing. Because a limited number of ovipositors were studied for each species, a range in the observed variation (e.g., for the ovipositor: relative size of pits at base and middle, relative height of pits, shape of pits, total number of annuli, annulus numbers between basal and apical sections of sheath, ridge development on apical pits and on ventral surface of lancet on annuli before the teeth annuli). For a few species, distances between pits 1 and 2, 4 and 5, and 9 and 10 of the ovipositor relative to the ovipositor diameter (including lance and lancet) between these pairs of pits is given. Other measurements were recorded as required. Measurements considered useful are given in Tables 1-5 in the “Appendix for statistical data”. Range of a measurement is given in the identification keys based on the calculation of two standard deviations. If a measurement falls within the overlap between values of the calculated two standard deviations, the character was rejected in favor of other characters, but if it is outside the range of the overlap portion, it is considered as a useful key character with a 1% chance of error.
Barcode information
For each specimen the following is recorded: country, year, state/province, specimen code, and number of base pairs.
Biology
Our knowledge of the biology of Siricidae is uneven. We know very little about most genera and species except for Sirex noctilio, which, as the major pest of pines in the Southern Hemisphere, was the focus of an intense and successful classical biological control program in the 1960s, 70s and 80s (Haugen and Underdown 1990, Haugen et al. 1990). Much of what we know about the biology of S. noctilio has been summarized in review papers by Morgan (1968) and Talbot (1977) and most recently in several chapters of the book The Sirex Woodwasp and its Fungal Symbiont (Slippers et al. 2011). We do not attempt to match the details of these works here but instead present a generalized version of siricid biology, leaning heavily on our knowledge of S. noctilio. Although we use it as our model species, it is important to recognize that S. noctilio differs fundamentally from most other species in that, where it is adventive, it attacks and kills stressed but relatively healthy trees. In its native range, like most other siricids, it is relatively benign.
The central paradigm of siricid woodwasp biology is that they live in symbiotic relationships with basidiomycete wood decay fungi (Buchner 1928, Cartwright 1929, 1938, Clark 1933, Francke-Grossman 1939, Stillwell 1960, 1962, 1964, 1965, 1966, 1967 and Gaut 1969, 1970, Slippers et al. 2003, among others). Female woodwasps carry fungal arthrospores, oidia or hyphal fragments in paired abdominal glands (intersegmental pouches) called mycangia and inoculate their tree host with fungus at oviposition. The fungus grows through the tree and larvae feed on the fungus as they bore through the wood. This relationship is mutualistic and obligate as far as we know for all genera and species except the genus Xeris. Adult females of Xeris species have significantly reduced glands that do not contain a wood decay fungus. They oviposit exclusively into trees that have already been attacked by another genus of woodwasp and infested with an appropriate wood decay fungus (Franke-Grossman 1939, Stillwell 1966, Spradberry 1976, Fukuda and Hijii 1997).
Early literature attempting to associate siricid species with specific symbionts was confusing because it was difficult to identify the fungi using classical methods and the Siricidae were in need of revision (Morgan 1968, Talbot 1977). With the development of molecular identification methods and taxonomic revisions, associating each siricid woodwasp with its specific symbiont has become less problematic. To date, four species of basidiomycete wood decay fungi are associated with Siricidae. Tremex columba (Stillwell 1964), T. fuscicornis in Poland (Pažoutová and Šrǔtka 2007), T. longicollis in Japan (Tabata and Abe 1995), and Eriotremex formosanus (Schiff unpublished data from North America) use Cerrena unicolor whereas Sirex noctilio, S. nitobei from Asia and S. juvencus from Europe use Amylostereum areolatum (Gaut 1969, 1970); Urocerus japonicus and U. antennatus both from Japan use Amylostereum laevigatum (Tabata and Abe 1997, 1999) and all other siricids examined (including Sirex cyaneus, S. imperialis, S. areolatus, S. californicus, S. nigricornis, S. varipes, Urocerus californicus, U. flavicornis, U. gigas, U. augur and U. sah (Stillwell 1966, Gaut 1970, Schiff unpublished data) use Amylostereum chailletii. Although woodwasp/fungus specificity is generally accepted, a recent exception was the isolation of Amylostereum areolatum from two specimens of Sirex nigricornis (formerly edwardsii) that were reared from logs also infested with S. noctilio. Presumably, the S. nigricornis acquired A. areolatum when they fed on parts of the tree already infested by the symbiont from S. noctilio (Nielsen et al. 2009).
In the Sirex noctilio /Pinus radiata association, the symbiotic fungus has two basic functions; it provides food for developing woodwasp larvae and, in conjunction with phytotoxic mucus, it kills the tree, rendering it more suitable for fungal growth. Like most wood boring insects, siricids do not make the complex of cellulases necessary to digest wood and must either obtain them from symbionts or eat something that digests cellulose for them (Chapman 1982), in this case the symbiont itself (mycophagy). Indirect evidence suggests they do both. Sirex cyaneus larvae have been observed to live and grow for three months on pure culture of their symbiont (Cartwright 1929) and Kukor and Martin (1983) demonstrated that S. cyaneus acquired digestive enzymes from its fungal symbiont, Amylostereum chailletii. Fungal mediated nutrition is very important to Sirex noctilio and fungal growth is positively correlated with adult size and thus fecundity, and dispersal ability (Madden 1981).
The ability to kill the host tree with fungus and mucus distinguishes Sirex noctilio from most other siricids and is the reason why S. noctilio is a major pest of some hosts whereas most other woodwasps are not. Oviposition behavior of S. noctilio has been well studied. Females drill into stressed trees and depending on the tree’s response either deposit eggs followed by a dose of fungus and mucus in a separate shaft (Coutts and Dolezal 1969, Madden 1981), or they deposit only the fungus and mucus. In the latter case, injecting only fungus and mucus is adaptive because the tree is rendered more suitable for future oviposition. There are generic level differences in drilling behavior. Sirex species make from 1–4 drills per insertion of the ovipositor through the bark, only some of which contain eggs and/or fungus; Urocerus species make a single long drill with many eggs alternating with masses of fungus; Xeris species make from 1–5 long drills per insertion with a few eggs in each drill but no fungus (Spradbery 1977) and Tremex columba either leaves unfertilized eggs in the adult female emergence tunnel or up to 7 presumably fertilized eggs in each oviposition tunnel (Stillwell 1967). Siricids like other Hymenoptera are haplodiploid with unfertilized eggs becoming males and fertilized eggs developing into females. It is important to note that neither fungus nor mucus alone kills the tree — only in combination are they toxic (Coutts 1969a and b). The mucus, produced by glands in the female abdomen and stored in a median reservoir, weakens the tree’s immune response allowing the phytotoxic fungus to kill the tree. Woodwasps other than Sirex noctilio all have mycangia and mucus reservoirs but their function has not been well studied. Spradberry (1973) determined the effects of various combinations of mucus and fungus from three genera of woodwasps, Sirex, Urocerus and Xeris, on live trees or fresh branches of several coniferous hosts and found that Amylostereum areolatum and the mucus from Sirex noctilio on Pinus radiata was the most phytotoxic combination. This explains why S. noctilio has been such a great pest of P. radiata plantations in the Southern Hemisphere but does not explain the presence of mucus glands in non toxic species. Presumably, in other woodwasps the mucus helps condition the tree in a more subtle way to improve growth of the fungus. Recently, Tremex fuscicornis, adventive in Chile, has been reported to kill weakened hardwoods and even vigorous Acer negundo and Populus sp. (Baldini 2002, Ciesla 2003). Presumably, the combination of fungus and mucus from Tremex fuscicornis can kill selected hardwoods just as Sirex noctilio kills some pines. Perhaps comprehensive studies of the effects of fungus and mucus from different siricid species on a wide variety of exotic hosts may predict which species will become pests in adventive situations.
Adult behavior of Siricidae is poorly known except for Sirex noctilio. In general, males emerge from the tree earlier than females and fly to the tops of trees to form swarms (Madden 1982, Schiff unpublished data). Individual females are mated when they fly into the swarm; they then proceed to oviposit in weakened trees. Studies of S. noctilio indicate that females select the height of oviposition sites based on moisture content (Coutts and Dolezal 1965) and localized turgor pressure within the host (Madden 1968, 1981). Western North American Sirex and Urocerus species have been observed ovipositing in the base of burned trees where presumably the turgor pressure and moisture content are appropriate (Schiff unpublished data). At least in Sirex noctilio (Madden 1981), and presumably in other species, there is selection for host condition that is most favorable for growth of the fungal symbiont.
The life cycle of siricid woodwasps is quite varied. Some species develop in a single year others may take 2–3 years (Stillwell 1966, 1967) and some like Sirex noctilio and Tremex columba can rush part of the population through in less than one year while other individuals take a full year or more. Depending on the availability and quality of the fungus, there are from 6–12 larval instars (Stillwell 1928, 1967, Madden 1981) that can mine 5–20 cm for Sirex and Urocerus spp. and up to 3 m for Tremex columba up and down in the trunk of the host (Solomon 1995). Larvae are cylindrical and have a characteristic “S” shape with a cornus (spike) on the last segment. The cornus is thought to help the larvae pack the frass in the tunnel. When the larvae finish feeding they turn sharply to the outside of the tree leaving a characteristic “J” shaped end of the mine. As the exit mines are perpendicular to the surface of the tree, emergence holes are perfectly round. Female woodwasp larvae have paired hypopleural organs in the fold between the first and second abdominal segments (Parkin 1941, 1942, Stillwell 1965). These organs are believed to be involved with transfer of the symbiont to the adult (see Morgan 1968 and Talbot 1977 for discussion).
Most of our knowledge of the natural enemies of siricids comes from efforts to control Sirex noctilio in Australia. The primary effort was to search for natural enemies that controlled siricids in their native lands and determine if they could be used to control populations of S. noctilio adventive in Australia. Starting in the early 1960s a massive effort was made to search for and rear parasitic wasps (parasitoids of each siricid species are listed in a separate section of this publication). Many species were collected, reared, released and became established in Australia (Kirk 1974 and 1975, Spradberry and Kirk 1978, Taylor 1967a and 1967b and others) but the parasitoid wasp complex (including ichneumonids, ibaliids and stephanids) seldom killed more than 40% of the Sirex noctilio population and was not effective in preventing population outbreaks (Haugen et al. 1990). However, in 1962 nematode parasites were discovered in S. noctilio in New Zealand (Zondag 1962) and their biology was described a few years later (Bedding 1967, modified in 1972). The biology of the nematodes is intimately entwined with the biology of siricids and their fungal symbionts and is summarized briefly here. The nematode Beddingia (Deladenus) siricidicola has two alternate life cycles each with a different female morphology. The two forms, one mycetophagous and the other parasitic on siricids, are morphologically distinct and were originally thought to be representatives of two different nematode families, Neotylenchidae and Allantonematidae, respectively. The mycetophagous form feeds on fungal mycelium and will feed continuously for many generations as long as the fungus quality is maintained. If environmental conditions change or the nematode encounters a siricid larva, the alternate cycle begins. Juvenile nematodes develop into the alternate (parasitic) morphology and penetrate the cuticle of the siricid larva leaving a small dark mark at the entry site. In the haemocoel of the siricid larva, the nematode increases greatly in size, waiting to reproduce ovoviviparously when the woodwasp pupates. At the end of pupation juvenile nematodes emerge from their mother and migrate to the gonads of the adult woodwasp where they begin to feed on the eggs in the female or the testes in the male, respectively. The nematodes do not appear to affect the development or behavior of the adult wasp and when the female woodwasp emerges from the host she mates and oviposits in new trees. However, instead of depositing a new generation of woodwasps she deposits eggs filled with parasitic nematodes. As many woodwasps often oviposit into a single tree, the nematodes are quickly spread through the population, effecting control in as little as three years (Haugen and Underdown 1990). Male woodwasps infested with nematodes mate but do not transfer nematodes to females and are thus a dead end for the nematode. The use of nematodes to control woodwasps has been improved by development of techniques to handle nematodes and by selection of optimal strains (Bedding and Akhurst 1974, Bedding and Iede 2005, Bedding 2009). Seven species of nematodes parasitic on 31 host species (siricids or their parasitoids) have been described from around the world (Bedding and Akhurst 1978) and there are more awaiting description (Bedding, personal communication, Schiff, unpublished data). They can be divided into three groups based on their fungal associations. The mycetophagous form of Beddingia siricidicola feeds only on Amylostereum areolatum. The mycetophagous form of Beddingia rudyi, B. imperialis, B. nevexii, B. canii, B. proximus and an undescribed species feed only on Amylostereum chailletii and the mycetophagous form of Beddingia wilsoni feeds on both. Even though they do not carry a fungal symbiont of their own, Xeris species, like many of the wasps parasitic on siricids, can be parasitized by Beddingia species (Bedding and Ackhurst 1978, see table 2). This information is presented in a table in Bedding and Akhurst (1978) with the siricid hosts. Taxonomic revisions of the Siricidae and easier methods to identify fungal symbionts may change this information slightly; for example, Urocerus japonicus and U. antennatus are listed as using Amylostereum chailletii instead of A. laevigatum as their symbiont.
Although they cannot be easily manipulated to target a particular infestation, birds are also natural enemies of both adult and larval siricids. In Tasmania, the dusky wood swallow, the forest raven, and the spine-tailed swift, attacked mating swarms of Sirex noctilio in the tops of trees to such an extent that they altered sex ratios in the next year’s population (Madden 1982), and Spradberry (1990) found an overall larval predation rate of 28.8% by woodpeckers in a European study.
Hosts
Hosts of New World species of Siricidae are summarized from Cameron (1965), Middlekauff (1960), Ries (1951), Smith (1979) and specimens studied in collections. In the list below we have rearing records of New World Siricidae from 13 plant families and 76 plant species. The host cited is the plant on which the larvae actually fed or the female was found ovipositing, plant species on which adults were found resting are not included. For accidentally introduced siricid species, we consider only host plant records with plant species native or introduced to North America, and host plant genus records from the Palaearctic found also in North America as native or ornamental plant genera. In the “Hosts” section under each species of siricid species treated, we list the plant species attacked and, when possible, we add in parenthesis the number of specimens we have recorded from a given host. We also include published records if we are confident about the accuracy of the published siricid name.
Parasitoids
Parasitoids of Siricidae are not very diverse, but they are striking for their large size. Not all parasitoid species have large specimens, but most have specimens ranging from small to very large depending on size of the host specimen. They are all easily recognized at family and generic level, and in many instances at species level. The North American parasitoids of Siricidae are keyed for Megarhyssa, Pseudorhyssa, and Rhyssa (Ichneumonidae) (Townes and Townes 1960), for Ibalia (Ibaliidae) (Liu and Nordlander 1992, 1994), and for Schlettererius (Stephanidae) (Townes 1949, Aguiar and Johnson 2003). Adults of most species fly before the main flight period of their siricid host. Even when the host adults are flying commonly, some parasitoids can still be found. Oviposition may easily be observed when it occurs on the lower portion of a tree trunk. We observed a female of Megarhyssa macrura (Linnaeus) ovipositing for 15 minutes (Fig. A4.1). Miller and Clark (1935: 155) observed and illustrated the oviposition stages in Rhyssa persuasoria (Linnaeus). For more information on the biology of parasitoids and their host trees see Champlain (1922), Chrystal and Myers (1928a, 1928b), Chrystal (1930), Hanson (1939), Cameron (1965), Taylor (1977) and Kirk (1974, 1975). An unusual behaviour of Megarhyssa is described by Fattig (1949). Males were observed inserting their abdomen for some time into the emergence hole of a female. Then, they waited for the female to emerge, and mated several times. A female parasitoid may visit the same tree several times in search of hosts.
New World species of parasitoids associated with Siricidae are listed below. Because it is often difficult to associate a parasitoid with a siricid host we also provide a list of named tree species as a clue. The flight period and range for each parasitoid species is then given.
To read a summary about the range and flight period of each species of parasitoid, please click on the corresponding name in the table and/or scroll below.
| Parasitoid species | Siricid species | Tree name & note |
| IBALIIDAE | ||
| Ibalia anceps Say (Fig. A4.2) | Tremex columba (Linnaeus) | See host trees under T. columba |
| Ibalia arizonica Liu & Nordlander | Conifer Siricidae | |
| Ibalia kirki Liu & Nordlander | Perhaps Sirex nitidus (T. W. Harris) | Picea engelmannii |
| Ibalia leucospoides (Hochenwarth) (Fig. A4.3) | Sirex sp., S. behrensii (Cresson), Sirex noctilio Fabricius, S. cyaneus Fabricius, S. areolatus (Cresson), S. nigricornis Fabricius, Urocerus sp., U. albicornis (Fabricius), Xeris sp. | Various conifers genera; common in Pinus resinosa |
| Ibalia montana Cresson | Probably conifer Siricidae | |
| Ibalia ruficollis Cameron | Probably conifer Siricidae | |
| Ibalia rufipes Cresson | Sirex cyaneus Fabricius or S. nitidus (T. W. Harris) | Various conifers genera |
| ICHNEUMONIDAE | ||
| Megarhyssa atrata (Fabricius) (Fig. A4.4) | Tremex columba (Linnaeus), Urocerus sp. (unlikely host) | See host trees under T. columba |
| Megarhyssa greeni Viereck | Tremex columba (Linnaeus) | See host trees under T. columba |
| Megarhyssa macrura (Linnaeus) (Fig. A4.5) | Tremex columba (Linnaeus) | See host trees under T. columba |
| Megarhyssa nortoni (Cresson) | Sirex noctilio Fabricius, Urocerus albicornis (Fabricius), Xeris morrisoni (Cresson) | Abies concolor, A. grandis, A. lasiocarpa, A. magnifica, Picea sitchensis, Pinus contorta, P. jeffreyi, Pseudotsuga menziesii, Tsuga canadensis |
| Rhyssa alaskensis Ashmead | Siricidae on conifers | Abies lasiocarpa, Picea englemannii, P. sitchensis, Pinus contorta, Tsuga heterophylla |
| Rhyssa crevieri (Provancher) | Sirex noctilio Fabricius, Urocerus albicornis (Fabricius) | Abies balsamea |
| Rhyssa hoferi Rohwer | Siricidae on conifers | Juniperus sp., Pinus edulis, P. ponderosa |
| Rhyssa howdenorum Townes & Townes | Sirex cyaneus Fabricius, S. nigricornis Fabricius | Pinus virginiana |
| Rhyssa lineola (Kirby) (Fig. A4.6) | Sirex sp., Sirex nigricornis Fabricius, S. cyaneus Fabricius or S. nitidus (T. W. Harris), S. noctilio Fabricius, Urocerus albicornis (Fabricius), U. flavicornis (Fabricius) | Abies balsamea, A. fraseri, A. lasiocarpa, Picea sitchensis, Pinus radiata, P. rigida, Tsuga canadensis |
| Rhyssa persuasoria (Linnaeus) (Fig. A4.7) | Sirex areolatus (Cresson), S. cyaneus Fabricius, S. noctilio Fabricius, Xeris sp. | Abies balsamea, A. concolor, A. lasiocarpa, Juniperus scopulorum, Larix decidua, Picea engelmannii, Pinus edulis, P. ponderosa, P. virginiana |
| Rhyssa ponderosae Townes & Townes | Sirex areolatus (Cresson) | Pinus ponderosa |
| Pseudorhyssa nigricornis (Ratzeburg) (Fig. A4.8) | Cleptoparasite on Rhyssa spp. | Abies balsamea, A. concolor, Larix laricina; Picea engelmannii, P. mariana, Pinus ponderosa, |
| STEPHANIDAE | ||
| Schlettererius cinctipes (Cresson) (Fig. A4.9) | Sirex sp., Sirex noctilio (in Tasmania), Urocerus sp., Xeris sp. | Abies concolor, Picea engelmannii, Pinus ponderosa, Pseudotsuga menziesii |
Ibaliidae – Ichneumonidae – Stephanidae
Ibaliidae
Ibalia anceps adults have been captured from mid April to late July and, rarely, in early September (Smith and Schiff 2002). Their main flight period, from between early June to mid-July, is well ahead of the Tremex columba flight. The range is from Minnesota and Nova Scotia in the North to Colorado, Texas and Florida in the South (Liu and Nordlander 1992).
Ibalia arizonica is recorded from Arizona and New Mexico where conifers grow (Liu and Nordlander 1992). No other information is available.
Ibalia kirki is recorded from Arizona and New Mexico where conifers grow (Liu and Nordlander 1992). No other information is available.
Ibalia leucospoides adults have been captured from mid April to early October. The main flight period is from July to early October (Smith and Schiff 2002). The range is from Alaska and Nova Scotia in the North to California and Florida in the South, where conifers grow (Liu and Nordlander 1992). Flanders (1925) observed that horntails attack nearby Ibalia. The parasitoid biology was treated by Hanson (1939).
Ibalia montana adults have been captured in July (Kirk 1975). The range is from British Columbia and Montana in the North to California and New Mexico in the South (Liu and Nordlander 1992).
Ibalia ruficollis adults have been captured from mid July to early October. The main flight period is in August and September (Kirk 1975). The range is from Arizona and northern Mexico (Chihuahua) (Liu and Nordlander 1992).
Ibalia rufipes adults have been captured from early May to late July. The main flight period is all of July (Kirk 1975). The range is from Oregon and Quebec (it may occur across the boreal zone) in the North to California, Nevada, Arizona and Colorado in the South, where conifers grow (Liu and Nordlander 1992).
Ichneumonidae
Megarhyssa atrata adults have been captured from mid May to early August. The main flight period is in June. The species is divided into two subspecies. The range of M. atrata atrata is from Wyoming, Minnesota to Massachusetts in the North to eastern Texas and Georgia in the South (host data by Walsh and Riley 1868, Riley 1870, Thomas 1876, Riley 1888, Packard 1890). The range of M. atrata lineata Porter is from Ontario, Quebec, New York and New Hampshire (Townes and Townes, 1960).
Megarhyssa greeni adults have been captured from mid May to early August for M. greenei greenei or March, April and September for M. greenei florida Townes. The main flight period is in June and early July. The range of M. greenei greenei is from Minnesota and Quebec in the North to Alabama and Georgia in the South. The range of M. greenei florida Townes is central Florida (Townes and Townes 1960).
Megarhyssa macrura adults have been captured from mid May to late September. The main flight period is in late June and July. This widespread species is divided into three subspecies. The range of M. macrura lunator (Fabricius) is east of the Rocky Mountains from South Dakota, Ontario, Quebec and Maine in the North to New Mexico, Texas and Georgia in the South (host data by Walsh and Riley 1868, Riley 1870, Harrington 1882b, Riley 1888 (illustrated on larva of T. columba larva), Packard 1890, Felt 1905, Fyles 1917, Herrick 1935). The range of M. macrura macrura (Linnaeus) is Chihuahua (Mexico), Texas, South Carolina and Florida. The range of M. macrura icterosticta Michener is Utah, Colorado Arizona and New Mexico (Townes and Townes 1960).
Megarhyssa nortoni adults have been captured from late May to early August. The main flight period is in July. The species is divided into two subspecies, both associated with conifers. The range of M. nortoni nortoni is from southern British Columbia and southwestern Alberta in the North to southern California and New Mexico in the south. The range of M. nortoni quebecensis (Provancher) is from Ontario to Nova Scotia in the North to North Carolina in the South (Townes and Townes 1960).
Rhyssa alaskensis adults have been captured from late May to early September. The main flight period is in June and July. The range is from Alaska and Alberta in the North to California and New Mexico in the South (Townes and Townes 1960).
Rhyssa creveiri adults have been captured from late May to early September. The main flight period is in June. The range is from Minnesota, Ontario and Nova Scotia in the North to North Carolina in the South (Townes and Townes 1960).
Rhyssahoferi adults have been captured from April to August. The main flight period is in July (Kirk 1975). The range is Colorado to Arizona (Townes and Townes 1960).
Rhyssa howdenorum adults have been captured in April and June. The range is Alabama, Georgia, Nebraska, North Carolina, South Carolina and Virginia (Townes and Townes 1960, Kirk 1974).
Rhyssa lineola adults have been captured from mid May to late September. The main flight period is in July and August. The range is from southern British Columbia and Nova Scotia in the North to Wyoming and South Carolina in the South (Townes and Townes 1960).
Rhyssa persuasoria adults have been captured from late May to early September. The main flight period is late May to early July (Kirk 1975). The range is from southern British Columbia, Minnesota, Quebec and New Hampshire in the North to California, Arizona and North Carolina in the South (Townes and Townes 1960). The biology was treated by Hanson (1939).
Rhyssa ponderosae adults have been captured in April, May and June. The range is California (Townes and Townes 1960).
Pseudorhyssa nigricornis adults are cleptoparasites of Rhyssa. Adults have been captured from late May to late June (Townes and Townes 1960). Females search for an oviposition shaft of Rhyssa and oviposit into the same shaft with their narrower ovipositor. Wet siricid frass and vaginal gland secretions are attractants. The larva of P. nigricornis eliminates the Rhyssa larva and develops on the siricid larva (Couturier 1949, Spradbery 1969, Spradbery 1970).
Stephanidae
Schlettererius cinctipes adults have been captured from early June to early September. The main flight period is in July (Kirk 1975). The range is from southern British Columbia and Idaho in the North to California and Arizona in the South (Townes 1949, Aguiar and Johnson 2003). It has become established recently in eastern North America (Smith 1997). The biology was studied by Taylor (1967).
Distribution
The ranges of native species of Siricidae are grouped in six major distribution patterns. The transamerican distribution pattern extends from the Atlantic to the Pacific coasts usually centered in the boreal zone from Alaska to Newfoundland. The following species have this distribution pattern: S. nitidus, U. flavicornis and X. melancholicus. Occasionally a species with a more temperate range will be found from British Columbia to Newfoundland. The following species has this distribution pattern: U. albicornis.
Ranges restricted to regions father south (usually the southern boreal zone or further south) are divided into eastern and western distribution patterns.
The eastern distribution pattern varies greatly in extent. A range could extend as far west as east of the Cascades Mountains. Only one species shows such a wide range: Tremex columba. This species is centered in eastern Northern America but one color form occurs from the eastern edge of the prairie ecotone west to the eastern edges of the Great Basin. A more typical eastern range is one that extends from the Atlantic coast between Nova Scotia and the Gulf of Mexico to at most regions east of the Rocky Mountains and north of the prairie ecotone. The following species have this distribution pattern: S. cyaneus (south of New York the range is restricted to high Appalachian Mountains), S. nigricornis, U. cressoni and U. taxodii (this species was previously known to occur only in southeastern United States, but following its recent discovery in Ontario its range now fits with the above distribution pattern).
The western distribution pattern occurs from the Rocky Mountains to the Pacific coast and also includes the coniferous zone of highlands in the prairies such as the Cypress Hills in Alberta and the Black Hills in South Dakota. The following species have this distribution pattern: S. abietinus, S. areolatus, S. behrensii, S. californicus, S. longicauda, S. varipes, U. californicus, X. indecisus, and X. caudatus. These species extend widely from British Columbia down to California and probably northernmost Mexico south of California. Most have ranges extending north into southern British Columbia, but the ranges of S. abietinus and S. californicus extend as far north as southern Yukon or northernmost British Columbia. The range of X. tarsalis is restricted to the Pacific coast.
Species in southwestern United States that occur east of the Sierra Nevada and as far north as southern Utah and Colorado correspond to a variation of the western distribution pattern. All are probably found in Mexico at least along the Sierra Madre Occidental where there is a rich diversity of conifers. The following species show this distribution pattern: S. obesus, S. xerophilus, S. mexicanus, X. chiricahua and X. morrisoni.
Species found south of the Isthmus of Tehuantepec are part of another distribution pattern probably associated with the Guatemalan highlands. Only X. tropicalis has this pattern.
The Caribbean distribution pattern in the Greater Antilles is the most unusual. So far only two species have this pattern pattern: S. hispaniola (pine forests above 1000 m) and T. cubensis (low elevation).
The association of Siricidae with tree trunks and wood have pre–adapted them for worldwide travel, mostly by means of human activity involving international transport of wood products and untreated logs. Their concealed larvae and frequently a multi–year life cycle means they usually remain unnoticed until they become established in areas far outside their native ranges. The primary example is Sirex noctilio, native to the Palaearctic region, which has become established in pine plantations in Australia, New Zealand, southern South America, South Africa and, most recently, eastern North America. Numerous other alien siricids have been intercepted at Western Hemisphere ports of entry. The distribution patterns of the species that are now established in the new area are in flux because all are still expanding their ranges.
Five exotic species from the Palaearctic and Oriental regions have become established in the Western Hemisphere: Sirex noctilio in southern South America (Iede et al. 1998) and eastern North America (Hoebeke et al. 2005), Urocerus sah in eastern North America (Smith 1987), Urocerus gigas in Chile and Argentina (Smith 1988), Eriotremex formosanus in southeastern United States (Smith 1975b, 1996), and Tremex fuscicornis in Chile (Baldini 2002). Urocerus flavicornis has been reported from Brazil (Ries 1946) but it has not been confirmed since.
Interceptions at ports of entry give an idea of the movement of species. Benson (1943, 1963) reported Sirex areolatus, S. cyaneus, Urocerus albicornis, U. californicus, and U. flavicornis, as adventive but not established in Britain. We have seen and studied numerous intercepted specimens from Canada, New Zealand and United States. No doubt there are many other records of interceptions awaiting discovery in collections of various countries. We summarize data from Canada and the United States, based on identified adults found in collections. In the United States, records for the past 40 years (DRS unpublished) indicate that more than 12 species have been intercepted in incoming wood, dunnage, or other wood products. They originated from more than 20 countries and were intercepted at 30 different ports of entry, mostly along the eastern and western seaboards, and a few at the Mexican border. Many unidentified intercepted larvae could include additional species. Other than Sirex noctilio, the only exotic Siricidae known to be established in the United States are Urocerus sah and Eriotremex formosanus. It is surprising that more species of Siricidae have not become established because interceptions include species of Sirex, Urocerus, Xeris, and Tremex. At least six species of Sirex have been intercepted from Europe, eastern Asia, and Mexico. Based on adults, the earliest interception record for S. noctilio is 1978. Since then, it has arrived from at least six European countries and been intercepted at seven different ports along the eastern seaboard. Urocerus gigas is the most commonly intercepted species of Urocerus, mostly from European countries. Western Palaearctic and Asian species of Xeris have been intercepted at eastern and western ports; and several species of Tremex, mostly from eastern Asia, have been intercepted at western ports.
Within Canada and United States, siricid wasps have been found outside their native range emerging from imported structural wood. Eastern United States records for Sirex areolatus, S. behrensii, S. longicauda, and S. varipes from homes and other buildings result from importations in wood from the western United States (Smith 1979, Smith and Schiff 2002). They often emerge from structures several years after wood is used for construction. Records indicate that only S. areolatus may have become established in the southeastern states.
Identification Key
- Key to genera of Siricidae
- Key to Sirex species
- Key to Tremex species
- Key to Urocerus species
- Key to Xeris species
| 1. | A) | Minimum distance (at top of eye) between eyes 0.7-1.2 times as long as maximum height of eye (Fig. B1.1). | |
| B) | Distance between inner edges of antennal sockets 3.5-10.0 times as long as distance from outer edge of antennal socket to nearest edge of eye (Fig. B1.3). | ||
| C) | Flagellomeres flattened dorsoventrally (Fig. B1.5). | ||
| [Additional character. Eye narrow: 1.7-1.9 times as high as long except in male of Teredon cubensis with a long eye (1.3 times as high as long) causing a very narrow gena.] | |||
| . . . . . . . . 2 | |||
| – | a) | Minimum distance (at top of eye) between eyes 1.2-1.6 times as long as maximum height of eye (Fig. 1.2). | |
| b) | Distance between inner edges of antennal sockets 1.5-2.5 times as long as distance from outer edge of antennal socket to nearest edge of eye (Fig. B1.4). | ||
| c) | Flagellomeres circular or almost circular in cross section (Fig. B1.6). | ||
| . . . . . . . . 6 | |||
 |
|||
| 2(1). | A) | Fore wing vein 2r–m present (Fig. B1.7). | |
| B) | Fore wing vein 1cu–a not aligned with vein M, but joining vein Cu near middle or in basal 0,25 between veins 1m–cu and M (Fig. B1.9). | ||
| C) | Hind wing with hamuli present basal and apical to junction of veins R1 and C (as in Fig. B1.11). | ||
| . . . . . . . . 3 | |||
| – | a) | Fore wing vein 2r–m absent (Fig. B1.8). | |
| b) | Fore wing vein 1cu–a aligned or almost aligned with vein M (Fig. B1.10). | ||
| c) | Hind wing with hamuli present only apical to junction of veins R1 and C (Fig. B1.12). | ||
| . . . . . . . . 4 | |||
|
|||
| 3(2). | A) | Distance between inner edges of lateral ocelli subequal to distance from outer edge of lateral ocellus to nearest edge of eye (Fig. B1.13). | |
| B) | Hind wing vein 1r–m slightly longer than vein M; vein M slightly curved (Fig. B1.15). | ||
| C) | Metatarsomere 1 scarcely compressed laterally and lateral surface not twisted when seen in dorsal view (as in Fig. B1.17). | ||
| D) | Female: cercus broad at base of cornus (Fig. B1.19). | ||
| E) | Female: tergum 9 with median basin more than 1.5 times as wide as long and medial length about 0.5 as long as cornus (Fig. B1.21). | ||
| Siricosoma Forsius, 1933 | |||
| [Note. Only one species, Siricosoma tremecoides Forsius, from the Malay Peninsula.] | |||
| – | a) | Distance between inner edges of lateral ocelli more than 1.5 times as long as distance from outer edge of lateral ocellus to nearest edge of eye (Fig. B1.14). | |
| b) | Hind wing vein 1r–m clearly shorter than vein M; vein M markedly curved (Fig. B1.16). | ||
| c) | Metatarsomere 1 greatly compressed laterally and lateral surface twisted when seen in dorsal view (Fig. B1.18). | ||
| d) | Female: cercus very small at base of cornus (Fig. B1.20). | ||
| e) | Female: tergum 9 with medial basin about as wide as long and medial length about 2.0 times as long as cornus (Fig. B1.22). | ||
| Teredon Norton, 1869 | |||
| [Note. Only known species, Teredon cubensis (Cresson) from Cuba] | |||
|
|||
| 4(2). | A) | Antenna with 11-19 flagellomeres (Fig. B1.23). | |
| B) | Fore wing cell 2R1 about 0.5 times as long as cell 3R1; vein 2r-rs joining stigma near middle; stigma gradually attenuated even after junction with vein 2r-rs (Fig. B1.25). | ||
| C) | Male (only E. formosanus studied): antenna as long as length of fore wing costal cell and stigma combined (Fig. B1.27). | ||
| D) | Female: tergum 9 with disc of medial basin very convex and lightly to densely pitted (Fig. B1.29). | ||
| E) | Female: cercus present and thumb–like (Fig. B1.31). | ||
| Eriotremex Benson, 1943 | |||
| [Note. Twelve species restricted to the Oriental region and Papua New Guinea. One species, Eriotremex formosanus, accidentally introduced into southeastern United States.] | |||
| – | a) | Antenna almost always with fewer than 14 flagellomeres (Fig. B1.24). | |
| b) | Fore wing cell 2R1 at least 0.63 times as long as cell 3R1; vein 2r-rs joining stigma in apical 0.2–0.33; stigma before junction with vein 2r-rs parallel and beyond junction abruptly attenuated (Fig. B1.26). | ||
| c) | Male: antenna at most as long as length of fore wing costal cell (Fig. B1.28). | ||
| d) | Female: tergum 9 with disc of medial basin at most slightly convex, but usually flat to concave, and most of surface not pitted (Fig. B1.30). | ||
| e) | Female: cercus absent (Fig. B1.32). | ||
| . . . . . . . . 5 | |||
|
|||
| 5(4). | A) | Flagellomere 1 about 0.5 as long as flagellomere 2 (Fig. B1.33). | |
| B) | Fore wing cell 2R1 at most 0.7 times as long as cell 3R1 (Fig. B1.35). | ||
| C) | Head with setae (exclusive of those on occiput) enlarged at apex, club–like (Fig. B1.37). | ||
| D) | Frons with pits separated by 1-2 pit diameters (surface quite bright because surface between pits smooth) (Fig. B1.39). | ||
| Afrotremex Pasteels, 1951 | |||
| [Note. Two species known A. hyalinatus (Mocsáry) and A. violaceus Pasteels. Both only recorded from sub–Saharan Africa.] | |||
| – | a) | Flagellomere 1 at least 0.7 times as long as flagellomere 2 (Fig. B1.34). | |
| b) | Fore wing cell 2R1 at least 0.85 times as long as cell 3R1 (cell 2R1 is commonly subequal or clearly longer than length of 3R1) (Fig. B1.36). | ||
| c) | Head with setae gradually tapering sharply at apex (Fig. B1.38). | ||
| d) | Frons with pits dense and generally in contact with each other (Fig. B1.40). | ||
| Tremex Jurine, 1807 | |||
| [Note. Thirty three species known. Almost all species restricted to Palaearctic region except for one, Tremex columba Linnaeus, in North America. One species, T. fuscicornis (Fabricius), introduced into the Western Hemisphere.] | |||
|
|||
| 6(1). | A) | Gena behind eye with short ridge (Fig. B1.41). | |
| B) | Hind wing without cell 1A (Fig. B1.43). | ||
| C) | Metatibia with one apical spur (Fig. B1.45). | ||
| D) | Female: apical section of sheath without teeth in apical third of dorsal margin (Fig. B1.47). | ||
| Xeris A. Costa, 1894 | |||
| [Note. Ten species known. Three species in Palaearctic region and seven in New World.] | |||
| – | a) | Gena behind eye without ridge (Fig. B1.42). | |
| b) | Hind wing with cell 1A (Fig. B1.44). | ||
| c) | Metatibia with two apical spurs (Fig. B1.46). | ||
| d) | Female: apical section of sheath with teeth in apical third of dorsal margin (except in a few species of Urocerus in Asia) (Fig. B1.48). | ||
| . . . . . . . . 7 | |||
|
|||
| 7(6). | A) | Fore wing broadly rounded at apex (Fig. B1.49). | |
| B) | Fore wing with cell 1Rs2 short (2r–m and 3r–m slightly longer than veins Rs2 and M above and below) (Fig. B1.51). | ||
| C) | Fore wing with cell 3R1 short (2.2 times as wide as long) (Fig. B1.53). | ||
| D) | Flagellum with 10-11 flagellomeres, and middle flagellomeres about 1.5 times as long as high in lateral view (Fig. B1.55). | ||
| Sirotremex Smith, 1988 | |||
| [Note.One species, Sirotremex flammeus Smith, from Mexico. Only males known.] | |||
| – | a) | Fore wing angularly rounded at apex (Fig. B1.50). | |
| b) | Fore wing with cell 1Rs2 long (2r–m and 3r–m slightly or very clearly shorter than veins Rs2 and M above and below) (Fig. B1.52). | ||
| c) | Fore wing with cell 3R1 long (3.0-6.0 times as wide as long) (Fig. B1.54). | ||
| d) | Flagellum with 12 or more flagellomeres, and middle flagellomeres at least 2.0 times as long as high in lateral view (Figs. B1.56 & B1.57). | ||
| . . . . . . . . 8 | |||
|
|||
| 8(7). | A) | Dark sections of body with dark blue or green metallic reflections (Figs. B1.58 & B1.60). | |
| B) | Head entirely black with dark blue or green metallic reflections (Fig. B1.62), at most with dark brown on gena behind eye (Fig. B1.63). | ||
| C) | Fore wing with vein Cu1 complete or almost so (Fig. B1.66). | ||
| Sirex Linnaeus, 1761 | |||
| [Note. Twenty eight species known. Almost equally divided between the Palaearctic (15 species) and Nearctic (14 species) regions. One species, S. noctilio, introduced into temperate South America, New Zealand, Australia and South Africa.] | |||
| – | a) | Dark sections of body without dark blue or green metallic reflections (Figs. B1.59 & B1.61). | |
| b) | Head variably colored, but with at least a pale spot (white, light reddish brown or reddish brown) on gena behind eye in upper half (Figs. B1.64 & B1.65). | ||
| c) | Fore wing without vein Cu1 at most with a stump or very rarely complete on one wing only (Fig. B1.67). | ||
| [Additional character. Female: cornus long and constricted in almost all species; rarely small and not constricted as in S. longicauda.] | |||
| . . . . . . . . 9 | |||
|
|||
| 9(8). | A) | Gena densely pitted (Fig. B1.68). | |
| B) | Fore wing vein 2r–m displaced apically and joined to cell 3M (Fig. B1.70). | ||
| C) | Pronotum with vertical surface mainly smooth, with pits medially and along dorsal margin (Fig. B1.72). | ||
| D) | Female: tergum 9 with median basin about as wide as long, and with short and slightly divergent ridge edges at base; cornus narrow (Fig. B1.74). | ||
| Xoanon Semenov, 1921 | |||
| [Note. Two species recorded from China, eastern Russia and Japan.] | |||
| – | a) | Gena with almost no pits (Fig. B1.69). | |
| b) | Fore wing vein 2r–m more basal and joined to cell 2M (Fig. B1.71). | ||
| c) | Pronotum with vertical surface almost completely pitted (Fig. B1.73). | ||
| d) | Female: tergum 9 with median basin about 2.0 times as wide as long, and with long and very divergent ridge edges; cornus wide (Fig. B1.75). | ||
| Urocerus Geoffroy, 1785 | |||
| [Note. Thirty three known species. Most (28 species) restricted to Palaearctic region and few (7) in New World. Two of the New World species, Urocerus gigas and U. sah, introduced.] | |||
| 1. | A) | Metafemur black (Fig. B2.1). | |
| . . . . . . . . 2 | |||
| – | a) | Metafemur light reddish brown (Fig. B2.2). | |
| [Doubtful specimens from Alaska and Yukon key out through both parts of the couplets] | |||
| . . . . . . . . 10 | |||
|
|||
| 2(1). | A) | Metatarsomere 2 4-5 times as long as high (Fig. B2.3). | |
| B) | Sheath with basal section relative to apical portion less than 0.8 (Fig. B2.5). | ||
| C) | Ovipositor with more than 38 annuli. | ||
| [Additional character. Fore wing vein 3A clearly present.] | |||
| . . . . . . . . 3 | |||
| – | a) | Metatarsomere 2 1.5-3.5 times as long as high (Fig. B2.4). | |
| b) | Sheath with basal section relative to apical portion greater than 0.9 (Fig. B2.6). | ||
| c) | Ovipositor with fewer than 37 (usually 29-31) annuli. | ||
| . . . . . . . . 4 | |||
|
|||
| 3(2). | A) | Tibiae and tarsi reddish brown (Fig. B2.7). | |
| B) | Ovipositor with 13-18 annuli outlined by annulus line only (Fig. B2.11) followed more distally by 23-28 annuli with pits before teeth annuli (Fig. B2.9); 10–15 annuli (anterior to teeth annuli at apex of ovipositor) each with a ridge extending from pit to ventral margin (Fig. 2.9). | ||
| C) | Sheath with basal section relative to apical section less than 0.53 (if between 0.53 and 0.61, use only A and B) (See Fig. B2.5 for measurements). | ||
| Sirex longicauda Middlekauff, 1948 | |||
| – | a) | Tibiae and tarsi dark brown or black (Fig. B2.8). | |
| b) | Ovipositor with all annuli before apical teeth annuli with pits (Fig. B2.12); 5–7 annuli (anterior to teeth annuli at apex of ovipositor) each with a ridge from pit to ventral margin (Fig. B2.10). | ||
| c) | Sheath with basal section relative to apical section greater than 0.61 (if between 0.53 and 0.61, use only a and b) (See Fig. B2.5 for measurements). | ||
| Sirex areolatus (Cresson, 1867) | |||
|
|||
| 4(2). | A) | Abdomen mostly reddish brown and abdominal segment 10 entirely light reddish brown (Fig. B2.13). | |
| B) | Gena behind eye with a weakly outlined ridge (rounded and not sharp) (Fig. B2.16). | ||
| C) | Ovipositor pits (if necessary, remove apical section of sheath to see pits) 0.2 times as long as an annulus near middle or aligned with base of apical section of sheath (Fig. B2.18), and tibiae black and tarsi reddish brown. | ||
| [Additional character. Fore wing vein 3A present and extended along posterior wing margin. Ovipositor with very small pits at base.] | |||
| Sirex behrensii (Cresson, 1880) | |||
| – | a) | Abdomen black (Fig. B2.14), or mostly reddish brown and abdominal segment 10 with cornus black at least apically (Fig. B2.15). | |
| b) | Gena behind eye without ridge (Fig. B2.17). | ||
| c) | Ovipositor pits (if necessary, remove apical section of sheath to see pits) 0.12 times as long as an annulus (Figs. B2.20 & B2.21), or 0.3-0.7 times as long as an annulus near middle or aligned with base of apical section of sheath (Fig. B2.19), or if as C then tibiae light reddish brown. | ||
| . . . . . . . . 5 | |||
|
|||
| 5(4). | A) | Metatarsomere 2 with tarsal pad slightly shorter than ventral length of tarsomere (Fig. B2.22). | |
| B) | Ovipositor without pits in basal 0.4-0.5 or pits very small at base (Fig. B2.24). | ||
| C) | Tibiae and tarsi light reddish brown (Fig. B2.26) and abdomen black with dark blue metallic reflections (Fig. B2.29), or tibiae and tarsi completely black (one specimen from Alaska). | ||
| D) | Specimen from Alaska, Yukon, north of central Alberta and probably northernmost British Columbia. | ||
| [Additional character. Head dorsally with diameter of pits 0.15-0.25 that of lateral ocellus.] | |||
| . . . . . . . . 14 | |||
| – | a) | Metatarsomere 2 with tarsal pad about half as long as ventral length of tarsomere (Fig. B2.23). | |
| b) | Ovipositor with medium to large pits on all annuli before teeth annuli (Fig. B2.25). | ||
| c) | Tibiae and tarsi black (Fig. B2.27), or light reddish brown (Fig. B2.28) and most of abdomen reddish brown (Fig. B2.30). | ||
| d) | Specimen clearly south or east of region described in D. | ||
| . . . . . . . . 6 | |||
|
|||
| 6(5). | A) | Fore wing darkly tinted (Fig. B2.31a) or clear with darkly tinted bands near middle and apex (Fig. B2.31b). | |
| . . . . . . . . 7 | |||
| – | a) | Fore wing clear and slightly yellow tinted (Fig. B2.32). | |
| . . . . . . . . 9 | |||
|
|||
| 7(6). | A) | Gena in lateral view (Fig. B2.33) and in dorsal view (Fig. B2.35) with most pits relatively larger and 0–1 diameters apart (only a few pits farther apart). | |
| B) | Ovipositor pits near base (e.g., annuli 3–5) as long as pits of middle annuli or pits aligned with base of apical sheath section (0.3 or more than 0.37 times as long as annulus) (Fig. B2.37). | ||
| . . . . . . . . 8 | |||
| – | a) | Gena in lateral view (Fig. B2.34) and in dorsal view (Fig. B2.36) with most pits relatively smaller and 1–3 diameters apart (rarely, pits touching). | |
| b) | Ovipositor pits near base (e.g., annuli 3–5) shorter (about 0.25 as long as annulus) than pits of middle annuli or pits aligned with base of apical sheath section (about 0.3 times as long as annulus) (Fig. B2.38). | ||
| Sirex californicus (Ashmead, 1904)[dark leg form] | |||
| [Note. Adults of this species exist in two color forms. The dark-legged form keys out here. The pale-legged form keys out in couplet 13.] | |||
|
|||
| 8(7). | A) | Metatarsomere 2 in lateral view about 1.5 times as long as high (Fig. B2.39), and ventral tarsal pad about 0.5-0.7 times as long as tarsomere. | |
| B) | Mesoscutum with discal pits usually without tooth-like processes except at middle; some processes fused laterally into irregular transverse ridges (Fig. B2.41). | ||
| C) | Abdomen black. | ||
| D) | Ovipositor with pits near middle or pits aligned with base of apical section of sheath (if necessary, remove apical section of sheath to see pits) about as long as high and small, their length 0.3 as long as annulus (Fig. B2.43). | ||
| Sirex obesus Bradley, 1913 | |||
| – | a) | Metatarsomere 2 in lateral view 2.0-2.5 times as long as high (Fig. B2.40), and ventral pad 0.3-0.5 times as long as tarsomere. | |
| b) | Mesoscutum with most discal pits with tooth-like processes; most processes fused in many directions forming a net-like pattern (Fig. B2.42). | ||
| c) | Abdomen black or mainly reddish brown. | ||
| d) | Ovipositor with pits near middle or pits aligned with base of apical section of sheath (if necessary, remove apical section of sheath to see pits) 1.4–1.8 times as long as high and their length 0.37–0.45 as long as annulus (Fig. B2.44). | ||
| Sirex nigricornis Fabricius, 1781 | |||
|
|||
| 9(6). | A) | Femora brown. | |
| B) | Mesoscutum with most discal pits with processes; processes usually fused in many directions forming a net-like pattern (Fig. B2.45). | ||
| C) | Fore wing without vein 3A (Fig. B2.47). | ||
| D) | Ovipositor with pits (if necessary, remove apical section of sheath to see pits) near middle or aligned with base of apical section of sheath about 3.0 times as long as wide, their anterior end long and furrow-like (Fig. B2.49). | ||
| E) | Ovipositor thin and long: annulus length divided by ovipositor diameter at annulus between pits 1 and 2 = 1.9–2.4, and between pits 12 and 13 = 1.5–2.1 (Fig. B2.51). | ||
| Sirex xerophilus Schiff, n. sp. | |||
| – | a) | Femora black though sometimes dark brown dorsally. | |
| b) | Mesoscutum with most discal pits usually mainly round with tooth behind large pits; some processes fused laterally into irregular transverse ridges (Fig. B2.46). | ||
| c) | Fore wing with vein 3A (Fig. B2.48). | ||
| d) | Ovipositor with pits (if necessary, remove apical section of sheath to see pits) near middle or pits aligned with base of apical section of sheath 1.2–1.3 times as long as wide, their anterior end not extended as narrow furrow (Fig. B2.50). | ||
| e) | Ovipositor thick and short: annulus length divided by ovipositor diameter at annulus between pits 1 and 2 = 1.3, and between pits 12 and 13 = 1.0 (Fig. B2.52). | ||
| Sirex mexicanus Smith, n.sp. | |||
|
|||
| 10(1). | A) | Abdomen posterior to segment 2 or 3 almost completely reddish brown (Fig. B2.53). | |
| B) | Gena (Fig. B2.55) and vertex (Fig. B2.57) with pits large (diameter 0.3-0.4 times that of lateral ocellus) and dense (on gena and vertex pits 0.0-0.5 pit diameter apart). | ||
| C) | Metatarsomere 2 1.7 times as long as high (Fig. B2.59). | ||
| [Additional characters. Metatarsomere 2 in ventral view with tarsal pad 0.9 times as long as tarsomere. Sheath with apical section clearly shorter than basal section, their junction aligned between 15th and 16th annuli of ovipositor. Cornus in dorsal view short and clearly angular.] | |||
| Sirex hispaniola Goulet, n. sp. | |||
| – | a) | Abdomen black with dark blue metallic reflections (Fig. B2.54). | |
| b) | Gena (Fig. B2.56) and vertex (Fig. B2.58) with pits smaller (diameter 0.1-0.25 that of lateral ocellus) and scattered (on gena pits between 4-10 pit diameters apart, and on vertex 2-8 pit diameters apart). | ||
| c) | Metatarsomere 2 2.0-3.6 times as long as high (Fig. B2.60). | ||
| . . . . . . . . 11 | |||
|
|||
| 11(10). | A) | Head posterodorsally with setae each with or without small pit at base (Fig. B2.61). | |
| B) | Mesoscutum with most discal pits mainly round with tooth behind larger pits, giving a rasp-like pattern; few processes fused laterally into irregular transverse ridges (Figs. B2.63 & B2.64). | ||
| C) | Metatarsomere 2 with tarsal pad 0.3–0.4 as long as tarsomere (Fig. B2.66). | ||
| D) | Ovipositor pits (if necessary, remove apical section of sheath to see pits) near middle or pits aligned with base of apical section of sheath at least 0.5 as long as annulus length (Fig. B2.68). | ||
| [Additional character. Metatarsomere 5 black or dark brown.] | |||
| Sirex noctilio Fabricius, 1793 | |||
| – | a) | Head posterodorsally with setae with large, clearly outline pit at base (Fig. B2.62). | |
| b) | Mesoscutum with most discal pits with processes; processes usually fused in many directions forming a net-like pattern (Fig. B2.65). | ||
| c) | Metatarsomere 2 with tarsal pad 0.4–0.5 or 0.8 times as long as tarsomere (Fig. B2.67). | ||
| d) | Ovipositor pits (if necessary, remove apical section of sheath to see pits) near middle or pits aligned with base of apical section of sheath 0.1–0.4 times as long as annulus (Figs. B2.69-B2.71). | ||
| . . . . . . . . 12 | |||
|
|||
| 12(11). | A) | Tibiae light reddish brown and their dorsal surface almost always with dark blue with metallic reflections (Fig. B2.72). | |
| [Additional characters. Ovipositor pits near middle or aligned with base of apical section of sheath (if necessary, remove apical section of sheath to see pits) 1.5–2.0 times as long as wide and 0.3–0.4 times as long as length of annulus (Fig. B2.71). Fore wing clear, faintly yellow tinted, and without dark bands at middle and apex.] | |||
| Sirex varipes Walker, 1866 | |||
| – | a) | Tibiae completely light reddish brown (Fig. B2.73). | |
| . . . . . . . . 13 | |||
|
|||
| 13(12). | A) | Fore wing clear with dark bands at center and apex or completely darkly tinted (Fig. B2.74). | |
| B) | Metarsomere 5 completely black (Fig. B2.76). | ||
| C) | Metatarsomere 2 with tarsal pad about 0.5 times as long as ventral length of tarsomere (Fig. B2.78). | ||
| D) | Ovipositor pits near middle portion or aligned with base of apical section of sheath 1.5-2.0 times as long as wide and 0.3-0.4 as long as length annulus (Fig. B2.80). | ||
| Sirex californicus (Ashmead, 1904) [pale leg form] | |||
| [Note. This species has two color forms: the pale-legged form keys out here, and the dark-legged form in couplet 7.] | |||
| – | a) | Fore wing clear, faintly yellow tinted, and with at most a dark band at apex (Fig. B2.75). | |
| b) | Metarsomere 5 entirely light reddish brown or almost black in apical half (Fig. B2.77). | ||
| c) | Metatarsomere 2 with tarsal pad about 0.8 times as long as ventral length of tarsomere (Fig. B2.79). | ||
| d) | Ovipositor either without pits in basal 0.4–0.5, or pits present, almost as long as wide, and at most 0.25 times as long as annulus length (Figs. B2.81 & B2.82). | ||
| . . . . . . . . 14 | |||
|
|||
| 14(13). | A) | Ovipositor pits near middle or pits aligned with base of apical section of sheath 0.15–0.25 as long as annulus and present even on annulus 2 but much smaller than pits at middle; ovipositor annulus lines clearly outlined in basal 0.3–0.4 (Fig. B2.83). | |
| [Additional character. Lancet with length of annulus 10 1.27–1.85 times as long as width of ovipositor at this annulus.] | |||
| Sirex nitidus (Harris, 1841) | |||
| – | a) | Ovipositor pits near middle portion or pits aligned with base of apical section of sheath 0.0–0.14 times as long as annulus and pits absent in basal 0.4–0.5 of ovipositor; ovipositor annulus lines in basal 0.3 weakly outlined near dorsal edge or not outlined at all (Fig. B2.84). | |
| . . . . . . . . 15 | |||
|
|||
| 15(14). | A) | Sheath with basal section relative to apical section less than 0.87 (if between 0.87-1.0, use only B and C). | |
| B) | Lancet with length of annulus 10 greater than 1.82 times as long as width of ovipositor at this annulus (if between 1.76-1.82, use A and C) [based on 26 specimens, we found no values below 1.85] (Fig. B2.85). | ||
| C) | Cornus usually long (about 2.0 times as long as wide) and broad in basal half (Fig. B2.87). | ||
| Sirex abietinus Goulet, n. sp. | |||
| – | a) | Sheath with basal section relative to apical section greater than 1.0 (if between 0.87–1.0, use b and c). | |
| b) | Lancet with length of annulus 10 less than 1.76 times as long as width of ovipositor at this annulus (if between 1.76–1.82, use a and c) [based on 40 specimens, we found no values above 1.77] (Fig. B2.86). | ||
| c) | Cornus usually short (about 1.5 times as long as wide) and narrow in basal half (Fig. B2.88). | ||
| Sirex cyaneus Fabricius, 1781 | |||
| 1. | A) | Metafemur black (Fig. B2.89). | |
| . . . . . . . . 2 | |||
| – | a) | Metafemur mainly reddish brown (Figs. B2.90-B2.92). | |
| . . . . . . . . 5 | |||
|
|||
| 2(1). | A) | Legs completely black (including base of metatibia) (Fig. B2.93). | |
| [Additional characters. Head with dorsal surface coarsely pitted, but pits scattered.] | |||
| Sirex areolatus (Cresson, 1868) | |||
| – | a) | Fore and middle legs with tibiae and tarsi reddish brown or paler (mesotibia and/or mesotarsomere 1 partly brown or black on dorsal surface in some species) (Figs. B2.94 & B2.95). | |
| . . . . . . . . 3 | |||
|
|||
| 3(2). | A) | Head with dorsal surface finely pitted and the pits scattered (Fig. B2.96). | |
| . . . . . . . . 4 | |||
| – | a) | Head with dorsal surface coarsely and densely pitted (Fig. B2.97). | |
| [Additional characters. Abdomen black except for segments 5 and 6 (rarely an additional segment), or abdomen light reddish brown except for anterior segments.] | |||
| Sirex nigricornis Fabricius, 1781 | |||
|
|||
| 4(3). | A) | Metatibia with extreme base light reddish brown (Fig. B2.98). | |
| B) | Mesotibia and/or mesotarsomere 1 with dorsal surface light reddish brown and with brown or black spot dorsally (spot size varies from small to large) (Fig. B2.100). | ||
| Sirex nitidus (Harris, 1841) [in part] | |||
| [Notes. Many specimens of this color form seen from Alaska, northernmost British Columbia, and the Yukon Territory, and Saskatchewan east to Newfoundland. In a few of these specimens, abdomen completely black. In Alaska, femora commonly black, and mesotibia and mesotarsomeres 1–3 widely black.] | |||
| – | a) | Metatibia with base more widely light reddish brown (Fig. B2.99). | |
| b) | Mesotibia and mesotarsus completely light reddish brown (Fig. B2.101). | ||
| Sirex longicauda Middlekauff, 1948 | |||
|
|||
| 5(1). | A) | Metafemur completely reddish brown; metatibia light reddish brown or black (Figs. B2.102 & B2.103). | |
| B) | Gena black with dark blue metallic reflections (Fig. B2.105). | ||
| . . . . . . . . 6 | |||
| – | a) | Metafemur reddish brown and black along dorsal surface; metatibia brown (Fig. B2.104). | |
| b) | Gena brown posterodorsally (Fig. B2.106). | ||
| [Additional characters. Metatibia and metatarsus brown, not reddish brown or black; dorsal surface of head coarsely and densely pitted.] | |||
| Sirex behrensii (Cresson, 1880) | |||
|
|||
| 6(5). | A) | Metatibia and metatarsus reddish brown or paler, and base of metatibia not obviously pale (Fig. B2.107). | |
| B) | Gena posterodorsally with pits mostly touching (except S. californicus) one another to about one diameter apart, only a few pits farther apart (Fig. B2.110). | ||
| . . . . . . . . 7 | |||
| – | a) | Metatibia and at least metatarsomeres 1-3 almost completely black, and metatibia clearly light reddish brown at base or black (Figs. B2.108 & B2.109). | |
| b) | Gena posterodorsally with pits mostly 1–3 diameters apart, the pits rarely touching (Fig. B2.111). | ||
| . . . . . . . . 10 | |||
|
|||
| 7(6). | A) | Antenna black or, at most, pedicel and flagellomeres 1 and 2 brown (Fig. B2.112). | |
| B) | Fore wing clearly yellow tinted, especially the cells posterior to costal cell and stigma (Fig. B2.114). | ||
| [Additional character. Head densely pitted dorsally.] | |||
| Sirex obesus Bradley, 1913 | |||
| – | a) | Antenna with at least scape, pedicel and flagellomeres 1-5 light reddish brown (Fig. B2.113). | |
| b) | Fore wing clear, scarcely tinted (Fig. B2.115). | ||
| . . . . . . . . 8 | |||
|
|||
| 8(7). | A) | Antenna with scape, pedicel and flagellomeres 1-3 or 4 light reddish brown, remaining flagellomeres black (Fig. B2.116). | |
| B) | Head dorsally with scattered pits and pit diameter 0.15-0.3 times lateral ocellus diameter (Fig. B2.118). | ||
| Sirex californicus (Ashmead, 1904) | |||
| – | a) | Antenna almost completely reddish brown or paler (apical 2–4 flagellomeres darker in a few specimens) (Fig. B2.117). | |
| b) | Head dorsally densely pitted and pit diameter 0.3–0.4 times lateral ocellus diameter (Fig. B2.119). | ||
| . . . . . . . . 9 | |||
|
|||
| 9(8). | A) | Coxae black (as in Fig. B2.120). | |
| B) | Mesoscutum submedially with net-like arrangement of polygonal pits with distinct raised margins; pit diameter 0.5–1.0 times lateral ocellus diameter (Fig. B2.122). | ||
| Sirex xerophilus Schiff, n. sp. | |||
| – | a) | Coxae completely reddish brown (Fig. B2.121). | |
| b) | Mesoscutum submedially with mostly round pits usually separated from one another, and usually without raised margins; pit diameter 0.3–0.7 times lateral ocellus diameter (Fig. B2.123). | ||
| Sirex mexicanus Smith, n.sp. | |||
|
|||
| 10(6). | A) | Metatibia at base widely light reddish brown (Fig. B2.124). | |
| B) | Head with setae posterodorsally behind eye each with a small pit at their base or without pit (Fig. B2.127). | ||
| C) | Mesoscutum submedially with small pits, each usually with a tooth behind (giving a rasp-like pattern), the tooth usually not fused laterally with others (Fig. B2.129). | ||
| Sirex noctilio Fabricius, 1793 | |||
| – | a) | Metatibia at base narrowly light reddish brown (Figs. B2.125 & B2.126). | |
| b) | Head with setae posterodorsally behind eye each with a deeply outlined pit at their base (Fig. B2.128). | ||
| c) | Mesoscutum submedially with moderate to large pits, each often surrounded with raised margins forming a net-like pattern (Fig. B2.130). | ||
| . . . . . . . . 11 | |||
|
|||
| 11(10). | A) | Mesotibia and/or mesotarsomere 1 with brown to black spot on dorsal surface (Fig. B2.131). | |
| . . . . . . . . 13 | |||
| – | a) | Mesotibia and metatarsomere 1 completely light reddish brown (Fig. B2.132). | |
| . . . . . . . . 12 | |||
| [Note. In the range of Balsam fir in Alberta and perhaps Saskatchewan, males of S. cyaneus matching above two couplets cannot be segregated with certainty using this character. Elsewhere this character almost always (99%) works.] | |||
|
|||
| 12(11). | A) | Abdomen with tergum 8 (in most specimens) and sterna 8 and 9 (in all specimens) black or mainly so (Fig. B2.133). | |
| B) | Western Alberta and eastward. | ||
| Sirex cyaneus Fabricius, 1781 | |||
| [Note. In western Alberta the apex of abdomen is light reddish brown. Character works from Manitoba eastward. No males seen from Saskatchewan.] | |||
| – | a) | Abdomen with apical segments light reddish brown (Fig. B2.134). | |
| b) | Rocky Mountains and westward. | ||
| Sirex abietinus Goulet, n. sp. | |||
|
|||
| 13(12). | A) | Mesotibia dark brown on about 0.5 of outer surface and dark spot not expanded on inner and lateral surfaces; mesotarsomere 1 or 1 and 2 dark brown (Fig. B2.135). | |
| B) | Metatibia with base narrowly light reddish brown, the length of reddish brown area about as long as minimum width of tibia (Fig. B2.137). | ||
| C) | Abdomen with tergum 7 and sterna 7 and 8 black (Fig. B2.139) or light reddish brown (Fig. B2.140) (if the latter, use A, B, and D). | ||
| D) | Across North America where spruces grow. | ||
| Sirex nitidus (Harris, 1841) [in part] | |||
| [Note. Specimens with abdomen light reddish brown apical segments rarely seen in eastern North America, but commonly seen in western North America. In Alaska and probably Yukon, mesotibia very darkly and widely black as in S. varipes. Sirex varipes recorded only south of southern British Columbia.] | |||
| – | a) | Mesotibia black on about 0.7 of outer surface, and partly or completely covering lateral and inner surfaces; tarsomeres 1 and 2 or 1–3 black (Fig. B2.136). | |
| b) | Metatibia with base very narrowly light reddish brown, the length of reddish brown area shorter than minimum width of tibia (Fig. B2.138). | ||
| c) | Abdomen with apical segments light reddish brown (as in Figs. B2.140 & Fig. B2.141). | ||
| d) | Rocky Mountains westward. | ||
| Sirex varipes Walker, 1866 | |||
| 1. | A) | Body setae generally short; frons in lateral view with setae about 0.5 times as long as distance between inner edges of lateral ocelli (Fig. B3.1). | |
| B) | Female: cornus in lateral view with lateral edge protruded and angular in basal 0.3 (Fig. B3.3). | ||
| C) | Female: abdominal tergum 9 laterally with slightly raised, semicircular pit anterior to each seta and pit clearly separated from other such pits (Fig. B3.5). | ||
| D) | Female: metatarsomere 2 in lateral view with dorsal edge clearly convex (Fig. B3.7). | ||
| E) | Male: metatarsomere 5 as long as metatarsomere 2 (Fig. B3.9). | ||
| Tremex columba (Linnaeus, 1763) | |||
| – | a) | Body setae generally long; frons in lateral view with setae about as long as or longer than distance between inner edges of lateral ocelli (Fig. B3.2). | |
| b) | Female: cornus in lateral view with lateral edge straight in basal 0.3 (Fig. B3.4). | ||
| c) | Female: abdominal tergum 9 laterally with distinct circular pit surrounding each setae, and pit contiguous with other such pits (Fig. B3.6). | ||
| d) | Female: metatarsomere 2 in lateral view with dorsal edge almost straight (Fig. B3.8). | ||
| e) | Male: metatarsomere 5 as long as metatarsomere 2 + 3 (Fig. B3.10). | ||
| Tremex fuscicornis(Fabricius, 1787) |
| 1. | A) | Abdomen black with light reddish brown transverse bands on at least segment 2 and anterior half of segment 8 (Fig. B4.1). | |
| B) | Protarsomeres 2-5 reddish brown (Fig. B4.4). | ||
| [Additional character. Flagellum completely light reddish brown.] | |||
| . . . . . . . . 2 | |||
| – | a) | Abdomen black with or without white lateral spot on tergum 8 (Fig. B4.2), or partly to completely reddish brown but without light reddish brown transverse bands (Fig. B4.3). | |
| b) | Protarsomeres 2-5 black (Fig. B4.5). | ||
| . . . . . . . . 4 | |||
|
|||
| 2(1). | A) | Abdominal segment 7 light reddish brown (may be black at side) and segment 9 black (Fig. B4.6) or almost completely light reddish brown. | |
| B) | Pronotum black (Fig. B4.8). | ||
| C) | Metatibia almost completely light reddish brown except for brownish spot on medial surface in apical 0.2 (Fig. B4.10). | ||
| D) | Vertex covered with densely spaced pits (Fig. B4.12). | ||
| . . . . . . . . 3 | |||
| – | a) | Abdominal segment 7 black and segment 9 with light reddish brown transverse band in apical 0.5 (Fig. B4.7). | |
| b) | Pronotum reddish brown (Fig. B4.9). | ||
| c) | Metatibia mostly black except for a yellowish transverse band in basal 0.3 (Fig. B4.11). | ||
| d) | Vertex mostly smooth with few pits except along posterior edge of eye, just behind ocelli and on median longitudinal furrow (Fig. B4.13). | ||
| Urocerus sah (Mocsáry, 1881) | |||
|
|||
| 3(2). | A) | Tergum 8 entirely, tergum 9 in posterior half and tergum 10 (except posterolateral corners in some specimens) light reddish brown (Fig. B4.14). | |
| B) | Sheath with apical section more than 1.52 times as long as basal section (if between 1.31 and 1.52, use A). | ||
| Urocerus gigas (Linnaeus, 1758) | |||
| – | a) | Tergum 8 in basal half and only cornus on tergum 10 light reddish brown; (tergum 8 rarely completely black) (Fig. B4.15). | |
| b) | Sheath with apical section less than 1.31 times as long as basal section (if between 1.31 and 1.52, use a). | ||
| Urocerus flavicornis (Fabricius, 1781) | |||
|
|||
| 4(1). | A) | Antenna with at least basal 0.25–0.7 black, the remaining antennomeres white but brown to black at apex of last segment (Fig. B4.16). | |
| B) | Cornus completely reddish brown to light reddish brown (Fig. B4.18). | ||
| C) | Tergum 8 sublaterally with microsculpture reticulate between spiracle and pitted sculpticells dorsally and sculpticells clearly scale-like (Fig. B4.20). | ||
| . . . . . . . . 5 | |||
| – | a) | Antenna with at most the three to four basal antennomeres black, the remaining antennomeres white, or remaining antennomeres white except for 3–7 apical antennomeres brown (Fig. B4.17). | |
| b) | Cornus usually black, rarely partly light reddish brown (Fig. B4.19). | ||
| c) | Tergum 8 sublaterally without (at most suggested) microsculpture between spiracle and pitted sculpticells dorsally (Fig. B4.22) or reticulation outlined and sculpticells flat and scarcely elevated posteriorly (Fig. B4.21). | ||
| . . . . . . . . 6 | |||
|
|||
| 5(4). | A) | Abdomen reddish brown in at least apical half (including cornus) (Fig. B4.23). | |
| B) | Tergum 9 with dorsal surface lateral to tergum 8 entirely smooth and without reticulation, lateral surface reticulate but sculpticells flat and scarcely elevated posteriorly (best seen in posterior view of segment) (Fig. B4.25). | ||
| C) | Metatarsomere 2 in lateral view about 2 times as long as high (Fig. B4.27), and in ventral view tarsal pad about half as long as tarsomere. | ||
| D) | Sheath with length of apical section less than 1.39 times basal section (if between 1.39 and 1.45, use A–C). | ||
| Urocerus cressoni Norton, 1864 | |||
| – | a) | Abdomen black, except cornus light reddish brown (Fig. B4.24). | |
| b) | Tergum 9 with dorsal surface lateral to tergum 8 smooth only medially near segment 8 and median basin, otherwise clearly reticulate laterally and sculpticells clearly scale-like (best seen in posterior view of segment) (Fig. B4.26). | ||
| c) | Metatarsomere 2 in lateral view about 3 times as long as high (Fig. B4.28), and in ventral view with tarsal pad more than 0.7 times as long as tarsomere. | ||
| d) | Sheath with length of apical section greater than 1.45 times basal section (if between 1.39 and 1.45, use a–c). | ||
| Urocerus taxodii (Ashmead, 1904) | |||
|
|||
| 6(4). | A) | Flagellum completely yellowish to light reddish brown (Fig. B4.29). | |
| B) | Wings clearly yellow tinted (Fig. B4.31). | ||
| C) | Metatarsomere 2 about 4.0 times as long as high (Fig. B4.33). | ||
| D) | Tergum 8 sublaterally without microsculpture between spiracle and pitted sculpticells dorsally, the surface shiny (Fig. B4.35). | ||
| Urocerus californicus Norton, 1869 | |||
| – | a) | Flagellomere 1 or 1 and 2 black, except for brown apical flagellomeres 3-7, remaining flagellomeres white to light reddish brown (Fig. B4.30). | |
| b) | Wings darkly tinted (Fig. B4.32). | ||
| c) | Metatarsomere 2 about 2.5 times as long as high (Fig. B4.34). | ||
| d) | Tergum 8 sublaterally with microsculpture and with clearly outlined meshes between spiracle and pitted sculpticells dorsally (Fig. B4.36). | ||
| Urocerus albicornis (Fabricius, 1781) | |||
| 1. | A) | Antenna black at base and sharply white to light reddish brown in apical half (Fig. B4.37). | |
| B) | Abdomen with apical segments light reddish brown (Fig. B4.41) and metatibia mainly to completely black (Fig. B4.43). | ||
| . . . . . . . . 2 | |||
| – | a) | Antenna black (Fig. B4.38), black and light reddish brown at base (pale and dark portions not sharply divided) (Fig. B4.39), or completely light reddish brown (Fig. B4.40). | |
| b) | Abdominal segments 7-9 or 8 and 9 black (Fig. B4.42) and metatibia mainly black (Fig. B4.44), or apical abdominal segments light reddish brown and metatibia reddish brown or mainly black (if the latter, use a). | ||
| . . . . . . . . 3 | |||
|
|||
| 2(1). | A) | Femora, tibiae, tarsi, head capsule except yellow genal spot, and thorax completely black (Figs. B4.45 & B4.47). | |
| Urocerus cressoni Norton, 1864 | |||
| – | a) | Femora black except reddish brown at apex; metatibia in basal 0.25, protarsus mesotarsus and mesotibia, metatarsomeres 1 and 2 at base, and head capsule ventrally light reddish brown; pronotum reddish brown (Figs. B4.46 & B4.48). | |
| Urocerus taxodii (Ashmead, 1904) | |||
|
|||
| 3(1). | A) | Head mainly to completely reddish brown (Fig. B4.49) or genal white spot extending dorsally to medial area. | |
| B) | Antenna light reddish brown (Fig. B4.51). | ||
| . . . . . . . . 4 | |||
| – | a) | Head completely or mainly black in dorsal half, and with white genal spot restricted to area behind eye (Fig. B4.50). | |
| b) | Antenna black (Fig. B4.53), pale at base shifting to brown or black at apex (Fig. B4.52), or very rarely completely light reddish brown (if the latter, use a). | ||
| . . . . . . . . 5 | |||
|
|||
| 4(3). | A) | Head without pits on much of dorsal surface except pits usually present and usually small near posterior edge of eye, behind ocelli and along longitudinal median furrow (Fig. B4.54). | |
| B) | Head capsule black in at least ventral half (Fig. B4.56). | ||
| C) | Metafemur black and reddish brown in apical third, metatibia brown except basal fifth, metarsomere 1 brown except for reddish brown base and apex (Fig. B4.58); mesofemur black except apex; mesotibia and mesotarsomeres 1 and 2 light reddish brown; abdominal segments 7 (totally or partly), 8 and 9 black (Fig. B4.60). | ||
| Urocerus sah (Mocsáry, 1881) | |||
| – | a) | Head with large pits on much of dorsal surface except absent on genal spot behind eye (Fig. B4.55). | |
| b) | Head capsule completely light reddish brown (Fig. B4.57). | ||
| c) | Femora, tibiae (except light reddish brown basal third of mesotibia, most of protibia and all of protarsus) and at least tarsomeres 1 and 2 of middle and hind legs reddish brown (Fig. B4.59); abdominal segments 7-9 light reddish brown (Fig. B4.61). | ||
| Urocerus californicus Norton, 1869 | |||
|
|||
| 5(3). | A) | Metatarsomere 1 in lateral view 5.5-8.2 times as long as high (if between 5.5 and 6.3, use B) and its base with light reddish brown area about twice as long as high (Fig. B4.62). | |
| B) | Metatibia generally more than 7.0 times as long as high (if between 6.8 and 7.0, use A) (Fig. B4.64). | ||
| [Additional characters. Apex of metatarsomere 1 with narrow reddish brown transverse band. Head (except for white spot on gena) and pronotum black.] | |||
| Urocerus flavicornis (Fabricius, 1781) | |||
| [Note. If specimen from North America, then the character “A” range is 5.5–8.0 for U. flavicornis and 4.0–5.2 for U. albicornis, and the character “B” range is 5.5–7.0 for U. albicornis and 6.8–9.0 for U. flavicornis.] | |||
| – | a) | Metatarsomere 1 in lateral view 4.0–5.5 times as long as high (if between 5.5–6.3, use b) and its base with light reddish brown area about 1.0 or 1.5 times as long as high (Fig. B4.63). | |
| b) | Metatibia generally less than 6.8 times as long as high (if between 6.8-8.5, use a) (Fig. B4.65). | ||
| . . . . . . . . 6 | |||
|
|||
| 6(5). | A) | Abdominal tergum 7 at least mainly black (Fig. B4.66). | |
| B) | Metatarsomere 1 in lateral view 4.0–4.4 times as long as high (if between 4.5–5.2, use A), its base with light reddish brown area about as long as high and its apex black or dark brown (Fig. B4.68). | ||
| [Additional characters. Abdomen with tergum 2 usually black; antenna usually black at least apically; pronotum dorsally usually partly to mostly reddish brown, rarely entirely black; head usually partly or mostly reddish brown ventral to antennal sockets.] | |||
| Urocerus albicornis (Fabricius, 1781) | |||
| – | a) | Abdominal tergum 7 mainly or completely reddish brown (Fig. B4.67). | |
| b) | Metatarsomere 1 in lateral view 5.3–6.3 times as long as high (if between 4.5–5.2, use a), its base with light reddish brown area about 1.5 times as long as high and its apex reddish brown (Fig. B4.69). | ||
| [Additional characters. Abdomen with tergum 2 reddish brown, rarely black; antenna usually all white, rarely darkened in apical 0.25; pronotum black dorsally, rarely with white area laterally on vertical surface ventral to anterolateral corner; head rarely with reddish brown spots ventral to antennal sockets.] | |||
| Urocerus gigas (Linnaeus, 1758) | |||
| 1. | A) | Gena in dorsal view with lateral angle not prominent (Fig. B5.1), the maximum distance between outer genal edges thus at most about as wide as maximum distance between outer edges of eyes (Fig. B5.3). | |
| B) | Maximum eye height in lateral view 0.53–0.61 times maximum head height (measured from genal ridge) (Fig. B5.5). | ||
| C) | Female: tibiae black and tarsi light reddish brown (Fig. B5.8). | ||
| D) | Female: sheath with length of basal section about 0.5 times length of apical section (Fig. B5.11); apical section without longitudinal ridge between dorsal and ventral edges (Fig. B5.11, insert). | ||
| E) | Female: ovipositor with pits on each annulus anterior to teeth annuli at apex (Fig. B5.14) and each pit with anterior end extending toward preceding annulus as a shallow furrow (as in middle and apex Fig. B5.14); sheath with junction of basal and apical sections aligned between annuli 8 and 9 of ovipositor. | ||
| Xeris tarsalis (Cresson, 1880) | |||
| – | a) | Gena in dorsal view with lateral angle more prominent (Fig. B5.2); the maximum distance between outer genal edges at least slightly wider than maximum distance between outer edges of eyes (Fig. B5.4). | |
| b) | Maximum eye height in lateral view at most 0.51 times maximum head height (measured from genal ridge) (Figs. B5.6 & B5.7). | ||
| c) | Female: tibiae and tarsi similar in color: black (Fig. B5.9) or light reddish brown (Fig. B5.10). | ||
| d) | Female: sheath with length of basal section at most 0.46 times length of apical section (Figs. B5.12 & B5.13); apical section with longitudinal ridge between dorsal and ventral edges (insert in Fig. B5.13). | ||
| e) | Female: ovipositor with pit only on apical 5–7 annuli anterior to teeth annuli (very small pit may be present on one or more additional annuli anteriorly) (Fig. B5.15); each pit with anterior end sharp and round, and shorter than 0.5 times annulus length (as in apex Fig. B5.15); sheath with junction of basal and apical sections aligned between 2 and 3, 3 and 4, or 4 and 5 annuli. | ||
| . . . . . . . . 2 | |||
|
|||
| 2(1). | A) | Wings darkly tinted over most or all of surface (Fig. B5.16). | |
| . . . . . . . . 3 | |||
| – | a) | Wings very lightly tinted or clear except for lightly tinted apical 0.25 (Fig. B5.17). | |
| . . . . . . . . 5 | |||
| [Note. Some specimens of X. indecisus could key through either alternate of this couplet.] | |||
|
|||
| 3(2). | A) | Gena below eye and genal ridge (including adjacent occiput) densely pitted (Fig. B5.18). | |
| B) | Gena with transverse ridge dorsal to mandible, broadly rounded and coarsely pitted (Fig. B5.20). | ||
| C) | Female: legs black (Fig. B5.22). | ||
| D) | Female: sheath with basal section 0.4 as long as apical section (Fig. B5.24). | ||
| Xeris tropicalis Goulet, n. sp. | |||
| [Note. Male not known, but characters A and B will help recognizing it.] | |||
| – | a) | Gena below eye and genal ridge (including adjacent occiput) with or without a few pits, the surface shiny (Fig. B5.19). | |
| b) | Gena with transverse ridge dorsal to mandible narrow, sharp and mainly smooth (Fig. 5.21). | ||
| c) | Female: at least tibiae and tarsi light reddish brown (Fig. B5.23). | ||
| d) | Female: sheath with basal section at most 0.35 times as long as apical section (Fig. B5.25). | ||
| . . . . . . . . 4 | |||
|
|||
| 4(3). | A) | Gena narrow, its maximum length from eye to genal ridge at most 0.50 times as long as maximum eye length (Fig. B5.26). | |
| B) | Female: coxae and femora black (Fig. B5.28). | ||
| C) | Female: flagellum brown or black in basal 0.3, gradually becoming light reddish brown in apical 0.6 (Fig. B5.30). | ||
| Xeris morrisoni (Cresson, 1880) | |||
| – | a) | Gena wide, its maximum length from eye to genal ridge at least 0.50 times as long as maximum eye length (Fig. B5.27). | |
| b) | Female: coxae brown usually becoming reddish brown apically, and femora light reddish brown (Fig. B5.29). | ||
| c) | Female: flagellum entirely light reddish brown (Fig. B5.31). | ||
| Xeris indecisus (MacGillivray, 1893) [in part] | |||
| [Note. Only females with reddish brown abdomen have darkly tinted wings and all are from southwestern United States or South Dakota.] | |||
|
|||
| 5(2). | A) | Vertex between eye and postocellar furrows with large, densely spaced pits over most of surface (many pits polygonal) (Fig. B5.32). | |
| B) | Gena below eye and genal ridge (including adjacent occiput) densely pitted; clypeus, face, frons and vertex with setae about 2.0 times as long as posterior ocellus (Fig. B5.34). | ||
| C) | Female: coxae black and rest of legs light reddish brown (Fig. B5.36). | ||
| D) | Male: metatibia with dorsal edge in lateral view very deeply indented in basal 0.3 (Fig. B5.39). | ||
| [Additional character. Pronotum in dorsal view with broad white longitudinal band along the lateral margin between anterior and lateral angles.] | |||
| Xeris chiricahua Smith, n. sp. | |||
| – | a) | Vertex between eye and postocellar furrows with mostly small, more sparsely spaced pits over most of surface (pits round) (Fig. B5.33). | |
| b) | Gena below eye and genal ridge (including adjacent occiput) with or without a few pits, the surface shiny; clypeus, face, frons and vertex with setae at most as long as posterior ocellus (Fig. B5.35). | ||
| c) | Female: coxae either completely light reddish brown (Fig. B5.37) or brown shifting to reddish brown apically (Fig. B5.38). | ||
| d) | Male: metatibia with dorsal edge in lateral view shallowly indented in basal 0.3 (Fig. B5.40). | ||
| . . . . . . . . 6 | |||
|
|||
| 6(5). | A) | Gena with white spot behind eye (very rarely absent) not extending to genal ridge (Fig. B5.41). | |
| B) | Gena with few, small pits between dorsal and ventral limits of genal ridge (Fig. B5.43). | ||
| C) | Female: abdomen black and coxae completely light reddish brown except near articulation of coxa to thorax (Fig. B5.45). | ||
| D) | Female: flagellum black, at most dark brown in apical 0.25 (Fig. B5.48). | ||
| E) | Male: femora mainly or completely light reddish brown (Fig. B5.51). | ||
| [Additional character. Pronotum in dorsal view with broad longitudinal band along lateral margin between anterior and lateral angles.] | |||
| . . . . . . . . 7 | |||
| – | a) | Gena with white spot behind eye large, extending to genal ridge (Fig. B5.42). | |
| b) | Gena with numerous, larger pits between upper and lower limits of genal ridge (Fig. B5.44). | ||
| c) | Female: abdomen black and coxae mainly brown laterally, becoming reddish brown near apex (Fig. B5.47) or abdomen mainly reddish brown and coxae reddish brown or procoxae at least brown laterally, becoming reddish brown apically (Fig. B5.46). | ||
| d) | Female: flagellum black, becoming light reddish brown (in specimens with black abdomen) (Fig. B5.49), or completely reddish brown (in almost all specimens with reddish brown abdomen and very rarely with those with black abdomen) (Fig. B5.50). | ||
| e) | Male: femora or at least metafemur completely or almost completely black (Fig. B5.52). | ||
| Xeris indecisus (MacGillivray, 1893) [in part] | |||
| [Note. Females with either black and reddish brown abdomens are found together except in southwestern United States where females with black abdomens have not been recorded.] | |||
|
|||
| 7(6). | A) | Female: sheath with basal section less than 0.25 times length of apical section (if 0.25–0.27, use B) (Fig. B5.53). | |
| B) | Range from mid latitudes of Alberta and British Columbia south to mountains of California and Northern Mexico, and east of cordillera in Alberta and perhaps as far east as north central Saskatchewan. | ||
| Xeris caudatus Cresson 1865 | |||
| [Note. Both sexes are difficult to recognize on morphological features, but can be distinguished by the CO1 barcode sequence. The general range is a good indication. This species occurs in the Rocky Mountains westward. East of the Rocky Mountains, in central Alberta, both species occur sympatrically.] | |||
| – | a) | Female: sheath with basal section more than 0.27 times length of apical section (if 0.25–0.27, use b) (Fig. B5.54). | |
| b) | Range from Alberta to Nova Scotia and south east of the prairie region Michigan to Maine. | ||
| Xeris melancholicus (Westwood, 1874) | |||
| [Note. Both sexes are difficult to recognize on morphological features, but can be distinguished by the CO1 barcode sequence. The general range is a good indication. This species occurs east of the Rocky Mountains and is sympatric with X. melancholicus in central Alberta (perhaps as far east as north central Saskatchewan]. | |||
Taxonomic Treatments
Family Siricidae
Diagnostic Combination
Both sexes of Siricidae are easily distinguished from all Symphyta (and probably all Hymenoptera) by the collar-like pronotum, and the cornus (horn) present on tergum 10 in females and on sternum 9 in males.
Description
General. Body length 7–38 mm, slender and mostly covered with long, more or less entangled setae. Males and females of the same species often differ considerably in color pattern and adults of most species may show great variation in size.
Head. In frontal view, head markedly constricted below the eye (Fig. A3.4). Malar space with well defined horizontal antennal groove between eye and mandible, sharply outlined ventrally. In posterior view, foramen magnum widely separated from mouth opening by occiput (Fig. C1.1). Mouthparts. Labrum small, finger-like and hidden under clypeus. Mandible with three teeth. Maxillary palp with 1 article; labial with 2 or 3 articles. Antenna. Scape with ventral surface flattened and concave, fitting into antennal groove when retracted (Fig. C1.2); pedicel wider than long and about 0.25 times as long as scape; flagellum with 4–30+ flagellomeres, flagellomere 1 as long as, longer, or shorter than following flagellomere (Fig. A3.11); flagellomeres each with sensory oval impression (often quite sharply outlined especially in female) on part or most of ventral surface (males in some genera, without sensory oval impression on apical flagellomeres) (Fig. A3.25).
Thorax. Pronotum long medially, collar-like with anterior margin slightly concave, and with acute anterolateral corners (Fig. C1.3). Propleura widely touching medially. Mesonotum with median lobe usually without notauli (except in Xeris, notauli slightly outlined in anterior third and far in front of scutellum) and each lateral lobe transversely divided by a wide, deep oblique furrow (possibly the precursor of the transscutal fissure) extending from scutellum posteromedially toward base of fore wing (Fig. C1.4). Tegula very small and mostly hidden under pronotal angle (the “tegula” of authors probably refers to the humeral plate). Mesoscutellum with a small, very narrow and sharply outlined posteromedian appendage. Legs. Tibial spur number: 1 (protibia), 1 (mesotibia), and 1 or 2 (metatibia). Tarsal pad (pulvillus) present on tarsomeres 1-4 and integrated within ventral surface of tarsomeres (slightly extended posteriorly in fresh specimens) (Figs. A3.27 & A3.28), without microtrichae, either smooth or papillate with scattered sensilla, almost as long as ventral length of tarsomeres 3 and 4, 0.4–0.8 times length of tarsomere 2, and 0.01–0.2 times length of tarsomere 1. Protibia with one row of spatula-like setae along posterodorsal margin. Pro- and mesotibiae with dorsal and ventral surfaces curved, commonly appressed to body. Pro- and mesofemora clearly longer than metafemur, their ventral or dorsoventral surface rasp-like, with numerous transverse ridges (Fig. C1.5). Female with tarsomere 1 0.7–1.0 times length of corresponding tibia. (Fig. C1.6). Male with hind leg greatly modified: tibia and tarsomeres 1–3 either thicker (Fig. C1.7) or compressed laterally and leaf-like (much less so on fore and middle legs) (Fig. C1.8); metatibia in lateral view with dorsal edge sinuate or sharply constricted in basal 0.3 and ventral edge sinuate in basal 0.3. Wings. Fore wing cell 3R1 enlarged toward apex (especially apical to vein 3r–m) and cell apex far from wing margin; fore wing veins R1 and Rs2 faint ending with a short petiole (Fig. C1.9); stigma very narrow; cell 1M much narrower (about 0.5 as wide) than cell 2M (Fig. C1.9); vein 2A with basal portion clearly outlined; vein 3A present or absent (Fig. C1.9). Hind wing with only one set of hamuli along edge, either only apical to vein R1 or apical and basal to vein R1 (Figs. B1.11 & B1.12); anal cell absent, or present and with apical petiole almost reaching wing edge (Fig. A3.29).
Abdomen. Tergum 1 divided medially (Fig. C1.10). Terga 2–8 with pit like sculpticells (surface similar to velvet) over most of median area (except in X. matsumurae) (Fig. C1.11). Female with tergum 8 in dorsal view with disc markedly extended posteriorly (Fig. A3.1); tergum 9 in lateral view greatly lengthened (about 0.3–0.5 times abdomen length) (Fig. A3.1) with sharp longitudinal furrows basolaterally (Fig. C1.12) and median basin dorsally (Fig. A3.12); median basin anteriorly outlined laterally by two sets of short furrows and extending posteriorly to base of tergum 10. Tergum 10 separated at least laterally from tergum 9 by transverse furrow and extended posteriorly as a wide or narrow horn (cornus) ending in a rod-like apex (Figs. A3.1 & A3.12); cercus present or absent anterior to anus, and usually very small when present (Figs. B1.31 & B1.32). Ovipositor. Sword-like, with both lance and lancet subdivided into annuli (Figs. A3.16 & A3.17). Lancet with 12-50 annuli, ventrally smooth (without teeth) but apical 3 or 4 annuli each with a large tooth laterally (Fig. A3.17); annuli before teeth annuli laterally each with apical pit, but pit present on as few as 3–5 apical annuli each with a pit (Figs. A3.16 & A3.17); if pits absent on basal annuli, the annuli either outlined or not. Male with sternum 8 deeply cleft medially and sternum 9 extended as a triangular horn ending with a rod-like apex (Fig. C1.13).
Taxonomic Notes
Viitasaari (1984) and Viitasaari and Midtgaard (1989) introduced sawfly taxonomists to pits on the ovipositor lancet. The character was first used by Kjellander (1945) to distinguish S. juvencus from S. noctilio. The ovipositor pits turned out to be crucial in deciphering the species of Sirex in the New World. Undoubtedly this character will be important in the study of Euroasiatic species of this genus and other genera.
The following keys to families of Hymenoptera include useful features to identify the family Siricidae: Ross (1937), Benson (1938), Smith (1988), Goulet (1992) and Mason (1993).
Range
Based on species listed by Taeger et al. (2010) and the species recognized here, there are 122 extant species known worldwide. These are grouped into ten genera classified traditionally in two subfamilies. Ninety-seven species are recorded from the Old World mostly in Eurasia, and 28 native species in the New World are known from Guatemala and the Dominican Republic north to the tree line in North America. Except for the introduced Sirex noctilio, Urocerus gigas and Tremex fuscicornis in South America, South Africa, Australia, and New Zealand, and two native species in equatorial Africa, there are no extant native species in the southern hemisphere. Siricidae are not known from oceanic islands.
In the New World, Siricidae are represented by seven extant genera (including one introduced into southeastern United States) and 33 extant species (including five introduced species). One species, Urocerus patagonicus Fidalgo and Smith – a Paleocene fossil from Patagonia (Argentina) – is the only native species recorded from the southern hemisphere (Fidalgo and Smith 1987). Twenty-eight native species are distributed as follows: Sirex – 13 species recorded north of Guatemala and the Dominican Republic, Sirotremex – one species restricted to Mexico, Teredon – one species restricted to Cuba, Tremex – one species in temperate regions of Canada, United States and northernmost Mexico, Urocerus – five species from Mexico northward, and Xeris – seven species from Mexico and northward. We have seen fewer than 25 specimens from Mexico representing five species, three of which are new. No doubt numerous species await discovery in the conifer zone of the Mexican highlands.
Subfamily Siricinae
Diagnostic combination
Both sexes of Siricinae are recognized by the fore wing junction of vein Rs originating from vein 1r–rs and ending typically at veins Rs and M (Fig. A3.30).
Diversity and Hosts
There are four genera and 64 extant species in the world, and three genera and 18 native species in the Western Hemisphere. Taeger et al. (2010) recognized 7 genera; here we synonymized one of these (Neoxeris) and transferred Sericosoma, Xeris and Neoxeris (a new synonym of Xeris discussed under this genus) to the Tremicinae. All reared specimens (three genera with known hosts) in this subfamily were from conifers.
Genus Sirex Linnaeus
Fig. C3.1 (live female, habitus)
Diagnostic Combination
Both sexes of Sirex are recognized by presence of the fore wing vein Cu1, the dark areas of the body with dark blue or green metallic reflections, the gena without ridge behind eye, and without a white spot dorsally. Females also have the cornus in dorsal view not constricted near the middle.
Description
Color. Black portions of body with dark blue or green metallic reflections, remaining pale surfaces, if present, light reddish brown to reddish brown.
Head. Antennal sockets with distance between their inner edges 1.5–2.0 times distance between inner edge of eye and outer edge of socket (Fig. C3.2). Distance between inner edges of lateral ocelli about as long as distance between outer edge of lateral ocellus and nearest edge of eye (Fig. C3.3). Maximum distance between outer edges of eyes clearly less than maximum width of head (thus, in frontal view, genal edge completely visible and not intersected by outer edge of eye) (Fig. C3.2). Minimum distance between inner edges of eyes about 1.5 times maximum eye height (Fig. C3.2). Gena without ridge behind eye and without white spot (at most with brown spot in males of one species) (Fig. C3.4), with large pits, each not elevated as low tooth. Head with setae sharp at apex. Antenna with 12 or more flagellomeres (the smallest specimens have the lowest number), and middle flagellomeres in dorsal view 1.5–3.0 times as long as wide; middle and apical flagellomeres with sensory pits over all except outer surface, apical 5–10 flagellomeres each with sensory oval impression on inner dorsal and inner ventral surfaces.
Thorax. Pronotum smooth or pitted over less than 0.5 of anterior surface. Mesoscutum densely pitted over median 0.5–0.7 only. Mesotarsomere 1 in lateral view not enlarged, its dorsal and ventral edges almost parallel and base of tarsomere at most 0.7 times its maximum width. Metatibia with two apical spurs, in male metatibia in lateral view 3.5–5.6 times as long as maximum width. In female, metatarsomere 2 in lateral view 1.5–5.0 times as long as maximum height. Metatarsomere 5 as long as metatarsomere 2 or metatarsomeres 2 + 3. Fore wing with apex acutely and angularly rounded, with vein 2r–m joined to cell 2M (as in Fig. B1.71), with vein 2r–m present, with cell 1Rs2 clearly wider than long, with cell 3R1 3.0-3.8 times as wide as long, with cell 2R1 about 0.5 times as wide as cell 3R1, with vein 2r-rs joining stigma near middle, with stigma gradually attenuated even distal to junction with vein 2r-rs (Fig. A3.30), with vein Cu1 almost always fully developed, with vein 1cu–a joining vein Cu about mid way between veins 1m–cu and M, with vein 2A adjacent to posterior edge of wing for 0.25 times length of cell 1A length (Fig. A3.30), and with vein 3A absent or present but short. Hind wing with anal cell 1A (as in Fig. 1.44); hamuli clearly present both basal and apical to junction of veins R1 and C (Fig. B1.11).
Abdomen. Female. Cornus in dorsal view short or long, lateral edges markedly to slightly convergent, but not constricted (Figs. B2.87 & B2.88). Tergum 9 with lateral edges of median basin slightly divergent, straight or almost so, and sharply outlined for less than 0.3 times median length of basin (Figs. B2.87 & B2.88), and with basin base (outlined by black furrows laterally) 0.85–1.5 times as wide as median length of basin. Cercus present but very small and wart-like. Sheath. Length of basal section 0.4–1.4 times as long as apical section; apical section without longitudinal lateral ridge, and with teeth in apical third of dorsal margin (as in Fig. B1.48) and each tooth usually with small seta at base. Ovipositor. Lancet with any of annuli 10–17 aligned with junction of basal and apical sections of sheath; first two or three annuli anterior to teeth annuli each with clearly outlined, open ended pit extending along most of annulus and most pits with ventral edge ridged; pits anterior to first annulus before teeth annuli large to very large and edge of annulus below pit sharply and acutely produced and clearly outlined to ventral edge of lancet (Fig. C3.5).
Diversity and Distribution
Sirex is diverse in the Northern Hemisphere with 28 extant species (15 known from the Palaearctic Region) (Taeger and Blank 2011, Taeger et al. 2010). This is the most diverse genus in the New World with 14 species, one of which, S. noctilio, was introduced from the Old World. The genus is widespread across North America. More species are expected from the Mexican highlands and perhaps the large Caribbean islands. We studied six Palaearctic species in addition to the Nearctic ones.
References
Species List
The 14 species treated are:
- abietinus Goulet, n.sp.
- areolatus (Cresson)
- behrensii (Cresson)
- californicus (Ashmead)
- cyaneus Fabricius
- hispaniola Goulet, n. sp.
- longicauda Middlekauff
- mexicanus Smith, n. sp.
- nigricornis Fabricius
- nitidus (T. W. Harris)
- noctilio Fabricius
- obesus Bradley
- varipes Walker
- xerophilus Schiff, n. sp.
Sirex abietinus Goulet, n. sp.
Fig. C4.1 (female habitus)
Fig. C4.2 (male habitus)
Fig. C4.4 (map)
Sirex juvencus race cyaneus Bradley, 1913: 14, (not S. cyaneus Fabricius, 1781: 419); accepted as subspecies by Ries 1951: 83, Middlekauff 1960: 65, Smith 1979: 126. This synonymy applies only to females from the Rocky Mountains and westward.
Sirex cyaneus Ries, 1951: 83 (not Fabricius, 1781: 419); Middlekauff 1960: 64, Smith 1979: 127. This synonymy applies only to females from the Rocky Mountains and westward.
Diagnostic Combination
Among females with a completely light reddish brown metafemur, short metatarsomere 2 (tarsomere 1.5 to 3.0 times as long as high), and long tarsal pad (pad 0.7–0.8 times as long as ventral length of tarsomere) [cyaneus, hispaniola, and nitidus], those of S. abietinus are recognized by the very small pits at the middle of the lancet (length 0.0–0.13 times as long as length of annulus), length of annulus 10 1.76–2.37 times as long as height of ovipositor (lance + lancet), and the lack of pits in basal 6–9 annuli of the ovipositor. Among males with a reddish brown metafemur and mainly black metatibia [cyaneus, nitidus, noctilio and varipes] those of S. abietinus are recognized by the completely light reddish brown mesotibia and mesotarsus, the generally larger pits on the gena and vertex (pit diameter 0.25–0.4 times lateral ocellus diameter), and the narrow pale spot at the base of the metatibia (spot extending slightly beyond minimum constricted portion and as long as or slightly longer than wide).
Adults of this species are extremely similar to those of S. cyaneus, but the range of S. abietinus is from the Rocky Mountains and westward.
Description
FEMALE
Color. Body, antenna and palps black with dark blue metallic reflections. Coxae black, femora, tibiae and tarsi light reddish brown (apical half of tarsomeres 5 occasionally darker but not dark brown or black, and femora black in one specimen from southern Yukon). Fore wing mainly clear, at most tinted light brown in apical third.
Head. Gena with pits 0.0–4.0 pit diameters apart; vertex especially on postocellar area with pits 0.0–2.0 pit diameters apart, and each pit diameter 0.15–0.25 times lateral ocellus diameter.
Thorax. Mesoscutum with coarse, net-like pits in median area. Metatarsomere 2 in lateral view 2.1–3.2 times as long as high, and its length about 1.0–1.2 times length of tarsomeres 3 + 4; tarsal pad 0.8–0.9 times as long as ventral length of tarsomere. Fore wing vein 3A absent.
Abdomen. Median basin of tergum 9 with basal width 0.65-1.2 times as long as median length, maximum width 1.1-1.4 times as long as median length, and median length 0.55-0.65 times cornus length (Fig. B2.87). Cornus in dorsal view usually long and thick, with edges straight and curved apically, its median length 1.2–1.4 as long as maximum width of abdomen at junction of terga 9 and 10 (Fig. B2.87). Sheath. Length 0.75–0.95 times fore wing length, basal section 0.75–1.0 times as long as apical section. Ovipositor. Lancet with 31–37 annuli (basal annuli weakly outlined); junction of basal and apical section of sheath aligned between 9th and 10th or 10th and 11th annuli, with 26–29 pits beginning with annuli 4–11 (Fig. C4.3). Pits near middle annuli or area at base of apical section of sheath 0.03–0.14 times as long as an annulus (pits gradually and markedly decreasing in size toward base), 0.15–0.4 times as high as lancet height in lateral view, and 1.0–1.7 times as long as high; annulus 10 length/ovipositor diameter (lance + lancet) 1.76–2.37 (based on 26 specimens) (Fig. B2.85). Last 4-6 annuli before teeth annuli as well as first tooth annulus with ridge on ventral edge of pit (Fig. C3.5). Edge of apical 6-8 annuli before teeth annuli extended as ridge to ventral edge of lancet (Fig. C3.5).
MALE
Color. Head, thorax and coxae black with dark blue metallic reflections. Coxae, metatibia (except extreme base), and metatarsomeres 1-3 black; femora, and tibiae and tarsus of fore and mid legs light reddish brown. Fore wing tinted light yellow. Abdomen with segments 1–3 (basomedian region from tergum 4 to as many as terga 4–7) black, segments 3–7 (excluding black median spot when present) light reddish brown, and sternum 9 light reddish brown rarely with some black at side.
Thorax. Metatibia 3.9-5.5 times as long as maximum width. Metatarsomere 1 in lateral view 3.1-3.4 times as long as maximum height.
Type Material
Holotype female (CNC), in perfect condition, labeled “Clearwater BC 20–VI–67” “66–6076–03 Abies lasiocarpa R’rd [reared] logs Coll [struck out]” [White label], “HOLOTYPE Sirex abietinus Goulet CNC No. 23907” [Red label]. Type locality: Canada, British Columbia, Clearwater.
Paratypes. 50 females and 10 males. CANADA. Alberta: Banff, 10.IX.1924 (1F, MTEC); Banff, 11,IX.1924 (1 F, MTEC). British Columbia: Atlin 22.VIII.1955 (1 F, CNC); Clearwater, 2.VIII, 3.VIII.1966, 31.V, 5.VI, 20.VI, 22.VI.1967, reared from Abies lasiocarpa (8F, 1M allotype [20.V], CNC); Forest Insect Survey 272, 6.VIII.1938 (1 F, CNC); Forest Insect Survey 393, 15.IX.1939 (1 F, CNC); Hope Mountains, 20.VIII.1931 (1 F; CNC); Lower Hazel Cr., 10.VIII (1 F, CNC); Lumberton 3.VIII.1935 (1 F, CNC); Mount Revelstoke, 6000’, 12.VIII.1923 (11 F, CNC); Quam Lake (1 F, CNC); Sarita River 2.VIII. 1946, 22.VII, 30.VII, 5.VIII..1948 (3 F, 3 M, CNC); Uslika Lake 5.VII, 20VII,1967, reared from Abies lasiocarpa (2 M, CNC); Uslika Lake 20.VII.1966, reared from Abies lasiocarpa (2 M, CNC); Mi 41, Uslika Lake Rd. 18.VI.1966, reared from Abies lasiocarpa (1 M, CNC); Vancouver, 18.VIII.1914 (1 F, CNC); Vancouver Island (1 F, CNC); Vernon, 30.VI, 5.VII.1965, reared from Abies lasiocarpa (3 F, CNC); White Pine Cr., 26.V, 3.VII.1967, reared from Abies lasiocarpa (2 M, CNC). Yukon Territory: Lake Laberge, 1929 (1 F, CNC); Whitehorse 27.VIII.1959 (1 F, CNC). USA. California: Napa Co., Angwin, 20.IX.1968 (1 F, USNM). Colorado: no data (1 F, USNM). Montana: Gallatin Co., Bozeman, 19.VIII.1984 (1F, MTEC); Rivali Co., Nezperce Mountain, VII.1923 (1F, MTEC). Nevada: Elko Co., Jarbidge, Hopk. U.S. 18677, 15.VIII.1929 (1 F, USNM). Oregon: Klamath Co., Crater Lake Nat. Park, Crater Springs (1 F, USNM); Sisters, 15.VII.1938, reared from Abies lasiocarpa, R. L. Furniss, Hopk. U. S. 31,766–S, barcode 00105829 (1 F, OSAC). Utah: Tabionia, 25.IX.1941, R. L. Furniss, barcode 00110916 (1 F, OSAC). Washington: Clear Lake, 24.II.1955, reared from Abies amabilis, cage 26, barcode and 00105775 (1 F, OSAC); Mount Rainier Nat. Park, Paradise Valley, Hopk. U.S. 4245a (1 F, USNM). Wyoming: Teton Co., Yellowstone Nat. Park, Old Faithful, 26.VIII.1925 (1 F, 2 M, USNM).
Taxonomic Notes
Sirex abietinus is a Nearctic species. Adults of this species are very similar to those of S. cyaneus, a Nearctic species. Sirex cyaneus should not be confused with the European “S. cyaneus”, a name incorrectly used in Europe for two European species that should be called S. torvus M. Harris (see chapter D. Additional Notes) and S. juvencus. The ovipositor of S. abietinus has no pits in basal 0.4, a character state that does not occur in either European species. Sirex abietinus is the western equivalent of the more eastern S. cyaneus. Sirex abietinus females have relatively long ovipositor annuli (value calculated only for annulus between pits 9 and 10) and, commonly, a thick and long cornus, and males have completely light reddish brown apical abdominal segments. Sirex cyaneus females have relatively short ovipositor annuli (value calculated only for annulus between pits 9 and 10) and a short cornus, and males (except in Alberta and perhaps Saskatchewan) have at least sterna 8 and 9 black (in most specimens, tergum 8 is completely black). The information from morphology and DNA barcoding shows a difference of almost 10.6% in the base pair number between S. abietinus and S. cyaneus. Clearly, the western populations (i.e., S. abietinus) are specifically distinct from S. cyaneus. The ranges of both species are allopatric. The two species have no known close relatives in Eurasia.
In western North America, this species is sympatric with S. nitidus and the pale femora form of S. californicus. In S. abietinus females, the pit size on the middle annuli of the ovipositor and the proportion of the length of the annulus between pits the 9 and 10 relative to the ovipositor diameter distinguish them from females of S. nitidus. In S. abietinus males (except specimens from Alberta and perhaps Saskatchewan) the middle leg color patterns distinguish them from S. nitidus males. Sirex abietinus females are easily distinguished from S. californicus females with pale femora by the long tarsal pad of metatarsomere 2, and the ovipositor pit size and shape at middle and base.
Though not yet within the range of S. noctilio, both sexes of S. abietinus are easily distinguished from S. noctilio by puncture size on the vertex and the pit development of the mesoscutum; females are easily separated by the long tarsal pad of metatarsomere 2 and the pit development near the middle of the ovipositor, and males by the reduced pale spot at the base of the metatibia.
Origin of Specific Epithet
This is an adjective derived from the genus name for the host tree, Abies, and abietinus means “of fir” because most specimens have been reared from fir.
Hosts and Phenology
Sirex abietinus was reared mainly (83%) from Abies spp. (Pinaceae) (Morris 1967 [as S. cyaneus from Abies lasiocarpa]). Kirk (1975) reared 453 specimens from Abies concolor and Picea engelmannii, but we suspect that most of the specimens reared from firs are S. abietinus and most of the specimens reared from spruce are S. nitidus. Based on 68 reared and confirmed specimens, other hosts are: Abies amabilis (2), A. lasiocarpa (56) (reported by Morris (1967) under the names S. cyaneus and S. juvencus), Picea engelmannii (4), P. glauca (may not have been reared) (1), P. sitchensis (may not have been reared) (1), and Tsuga heterophylla (4). We have only one record from Cupressus macrocarpa (Cupressaceae).
Based on 30 field collected specimens, the earliest and latest capture dates are July 20 and September 15. The main flight period is from late July to mid September with a peak in August.
Range
CANADA: AB, BC, YT. USA: CA, CO, MT, NV, OR, UT, WA, WY. Sirex abietinus, a western North American species, is known from southern Yukon and British Columbia south to California and Colorado (Fig. C4.4). It has been intercepted in England (Saunt 1924). We have seen one male from New Zealand (FRNZ).
Specimens studied and included for range map: 111 females and 44 males from BYUC, CNC, DEBU, EDUM, MTEC, OSAC, PFRC, USFS–GA, and USNM.
Specimens for molecular studies: 5 specimens. See Fig. E2.5e.
CANADA. British Columbia: 2008, CNCS 1029, 601; 2000, SIRCA 053, 612; 1969, SIRCA 064, 583; 2000, SIRCA 069, 553. USA. California: 1999, CBHR 103, 658.
Sirex areolatus (Cresson)
Fig. C5.1, Schiff et al. 2006: 20, 21 (female habitus)
Fig. C5.2, Schiff et al. 2006: 19 (male habitus)
Fig. C5.3 (map)
Diagnostic Combination
Among females with longer tarsi (metatarsomere 2 about 5.0 times as long as high) [longicauda] those of S. areolatus are recognized by their completely black legs. Males are recognized by their completely black legs.
Description
Color. Body, legs, palps and antenna black with dark blue metallic reflections. Fore wing darkly to lightly tinted.
Head. Gena with pits 1.0-5.0 pit diameters apart; vertex with pits 1.0-2.0 pit diameters apart, and each pit diameter about 0.25 times lateral ocellus.
Thorax. Mesoscutum with quite dense pits and numerous transverse ridges in median area. Metatarsomere 2 in lateral view about 5.0 times as long as high (Fig. B2.3); tarsal pad 0.35-0.5 times as long as ventral length of tarsomere. Wings. Fore wing vein 3A present and extending along posterior margin of wing.
Abdomen. Median basin of tergum 9 with basal width 0.6-1.1 times as long as median length, maximum width about 0.9-1.3 times as long as median length, and median length about 0.55-0.7 times as long as cornus length. Cornus in dorsal view long, attenuated in apical 0.25-0.3, and edges not angular midway; median length 1.2-1.5 times as long as maximum width of abdomen at junction of terga 9 and 10. Sheath. Length 0.95-1.2 times fore wing length; basal section 0.5-0.8 times as long as apical section (Fig. B2.5). Ovipositor. Lancet with 39-46 annuli (basal annuli clearly outlined); junction of basal and apical sections of sheath aligned between 10th and 11th to 12th and 13th annuli, with 35-41 pits beginning with annulus 2 (Fig. B2.12). Pits near middle annuli or area apical section of sheath about 0.15 times as long as an annulus (pits gradually decreasing in size toward base), about 0.3 times as high as lancet height in lateral view, and 1.0-1.2 times as long as high; annulus 10 length/ovipositor diameter (lance + lancet) not measured. Last two annuli before teeth annuli with ridge on ventral edge of pit. Edge of apical 5-7 annuli before teeth annuli extending as ridge to ventral edge of lancet (Fig. B2.10).
Color. Head, thorax, antenna, palps, abdominal segments 1, 2, 8, sterna 2 and 3 at side, and 8 black with dark blue metallic reflections; abdominal segments 3-7 mostly light reddish brown. Coxae and femora black (Fig. B2.93). Fore wing clear.
Thorax. Metatibia in lateral view 3.9-4.2 times as long as maximum width. Metatarsomere 1 2.8-3.1 times as long as maximum height.
Taxonomic Notes
Sirex apicalis Kirby was not examined, but the description, especially the leg color pattern, perfectly matches this species.
Biological Notes
Essig (1926) described adults and pupa as well as the microhabitats of the larvae and pupae. Chamberlin (1949) described pupae both in a stump and in adjacent soil.
Hosts and Phenology
The host range of S. areolatus is very wide (Flanders 1925, Essig 1926, Middlekauff 1960, Cameron 1965, Westcott 1971). Based on 76 reared and confirmed specimens, the main hosts are Cupressaceae: Cupressus macrocarpa (49), Juniperus occidentalis (20) (from scorched trees (Westcott 1998)), Calocedrus decurrens (2), Sequoia sempervirens (first recorded by Baumberger (1915), and also from fresh cut burnt trees by De Leon (1952)), and Taxodium distichum (5). They are less often recorded from Pinaceae: Pinus contorta, P. jeffreyi, P. lambertiana, P. radiata, and Pseudotsuga menziesii (Chamberlin 1949).
Based on 44 field-collected specimens, the earliest and latest capture dates are late June and late November. The main flight period is from early September to early October.
Range
CANADA: BC, NS. USA: AR, AL, AZ, CA (Middlekauff 1960), CO, ID, FL, HA, NM, OR, UT, VA, WA. Sirex areolatus is mainly a western North American species known from British Columbia to California and New Mexico (Fig. C5.3). It is adventive in eastern North America (FL, AR, AL, NS, VA) and Hawaii (Burks, 1967) and is probably not established. The species was also intercepted in England (Benson 1940), and we have seen one female from New Zealand (PANZ). However, Smith and Schiff (2002) think that the Virginia record may suggest an establishment in wild habitats.
Specimens studied and included for range map: 50 females and 84 males from BYUC, CNC, FSCA, OSAC, PFRC, UAIC, UCRC, and USNM.
Specimens for molecular studies: 15 specimens. See Fig. E2.5a.
CANADA. British Columbia: 2008, CNCS 1042, 601; 2007, CNCS 1043, 532; 2007, CNCS 1044, 601; 2007, CNCS 1045, 607. USA. California: 1997, CBHR 6, 658; 1999, CBHR 101, 658; 2006, CBHR 377, 658; 2006, CBHR 657, 658; 2006, CBHR 658, 658; 2006, CBHR 659, 658; 2006, CBHR 660, 658; 2006, CBHR 661, 658; 2006, CBHR 662, 658; 2006, CBHR 663, 658; 2006, CBHR 668, 658.
Sirex behrensii (Cresson)
Fig. C6.1, Schiff et al. 2006: 24, 25 (female habitus)
Fig. C6.2, Schiff et al. 2006: 23 (male habitus)
Fig. C6.4 (map)
Urocerus Behrensii Cresson, 1880: 35. Holotype female (ANSP), examined by DRS. Cresson 1916: 9. Type locality: California.
Sirex behrensii; Kirby, 1882: 379 (change in combination); accepted by Bradley 1913: 16, Ries 1951: 83, Middlekauff 1960, Smith 1979: 126.
Diagnostic Combination
Among females with a black metafemur and metatibia and short metatarsomere 2 (less than 3.0 as long as high) [californicus, mexicanus, nigricornis, obesus and xerophilus] those of S. behrensii are recognized by the reddish brown tarsi and the mainly reddish brown abdomen. Males are recognized by the metafemur with a reddish brown ventral half and a black dorsal half, and by the brown spot on the gena behind the eye and occipital margin.
Description
FEMALE
Color. Head, antenna, palps, thorax, abdominal segments 1 and 2, lateral surface of terga 3–9 or 3–10, and lateral surface of sterna 3–7 or 4–7 black with dark blue metallic reflections; most of terga 3–9, or all of tergum 9 and 10, and most of sterna 3–7 or 4–7 reddish brown (Fig. B2.13). Coxae, femora, most of tibiae, and most of or part of tarsomere 1 of fore leg or fore and middle legs black; apex and ventral half of tibiae, tarsomeres 2–5 of fore leg, 1–5 or 2–5 of middle leg, and metatarsus reddish brown. Fore wing in apical third and basal to stigma with darkly tinted bands (Fig. C6.3).
Head. Gena with pits 4.0–8.0 diameters apart between eye and posterior head margin; very dense on vertex and postocellar area, and each pit diameter about 0.25 times lateral ocellus. Gena with central surface with a round ridge between eye and occiput (Fig. B2.16).
Thorax. Mesoscutum with dense pits in median area; pits round, and transverse ridges moderately numerous. Metatarsomere 2 in lateral view 2.4–3.0 times as long as high; tarsal pad 0.4–0.5 times as long as ventral length of tarsomere. Fore wing vein 3A present and extending to posterior wing margin (Fig. C6.3).
Abdomen. Median basin of tergum 9 with basal width 0.8–1.0 times as long as median length, maximum width 1.1–1.7 times as long as median length, and median length 1.0–1.2 times as long as cornus length. Cornus in dorsal view short, with edges straight or slightly angular midway; its median length 1.0–1.2 as long as maximum width of abdomen at junction of terga 9 and 10. Sheath. Length 0.68–0.82 times fore wing length, basal section 0.93–1.17 times as long as apical section. Ovipositor. Lancet with 31–36 annuli (basal annuli clearly outlined); junction of basal and apical section of sheath aligned between 12th and 13th annuli, with 28–32 pits beginning with annulus 2. Pits near middle annuli or area at base of apical section of sheath, about 0.2 times as long as an annuli (pits gradually decreasing in size and very small toward base), about 0.3 times as high as lancet height in lateral view, and about 1.5 times as long as high (Fig. B2.18); annulus 10 length/ovipositor diameter (lance + lancet) not measured. Last 2-3 annuli before teeth annuli as well as first tooth annulus with ridge on ventral edge of pit. Edge of apical 5-7 annuli before teeth annuli extending as ridge to ventral edge of lancet.
MALE
Color. Head (except behind eye), thorax, antenna beyond flagellomere 6, palps, and abdominal segments 1 and 2 black with dark blue metallic reflections; smooth surface on gena between eye and posterior margin of occiput brown (Fig. B2.106); antennomeres 1-5, and abdominal segments 3-9 light reddish brown. Coxae, striated surface of femora of fore and middle legs, and dorsal 0.5 of metafemur black (Fig. B2.104); metatibia (except extreme base), apical 0.3–0.5 of mesotibia and mesotarsomeres 1–2, and metatarsomeres 1–3 and 5 brown to dark brown (Fig. B2.104); most of femora of fore and middle legs, ventral half of metafemur, tibiae and tarsi of fore leg, basal 0.3–0.7 of mesotibia, mesotarsomeres 3–5, metatarsomeres 4, and extreme base (spot about 0.5 times as long as minimum width of tibia at base) of metatibia light reddish brown. Fore wing clear.
Thorax. Metatibia 3.5-4.0 times as long as maximum width (Fig. B2.104). Metatarsomere 1 in lateral 2.7-3.5 times as long as maximum height.
Taxonomic Notes
Females of S. behrensii may be confused with the pale abdomen females of S. nigricornis. The clearly outlined banded wing pattern, the broad black longitudinal band along the side of the abdomen and completely reddish brown segment 10, and the presence of fore wing vein 3A should distinguish them from S. nigricornis females. Males are easily distinguished among New World Sirex by antenna and hind leg color patterns. Daly (1963) used specimens of S. behrensii for thoracic muscle studies.
Hosts and Phenology
The host range of S. behrensii is moderately wide (Flanders, 1925, Essig 1926, Middlekauff 1960, Cameron 1965). All but one hosts, based on 50 reared and confirmed specimens, are Pinaceae: Pinus Jeffreyi (2), P. lambertiana (1), P. ponderosa (46), P. radiata, and Pseudotsuga menziesii (1). One record is on Cupressus macrocarpa (Cupressaceae).
Based on 30 field-collected specimens, the earliest and latest capture dates are from early June late November. The main flight period is from late July to late October with a peak in late September.
Range
CANADA: BC. USA: CA (Middlekauff 1960), ID, NV, OH (probably not established), OR, WA, WV (probably not established). Sirex behrensii, a western North American species, is recorded from southernmost British Columbia to California and Nevada (Fig. C6.4). The specimen from Ohio was on imported lumber and is probably not established (Smith and Schiff 2002).
Specimens studied and included for range map: 32 females and 38 males from CNC, OSAC, PFRC, UCRC, and USNM.
Specimens for molecular studies: 13 specimens. See Fig. E2.5a.
CANADA. British Columbia: 2002, SIRCA 048, 416; 2002, SIRCA 050, 407; 2002, SIRCA 051, 575; 2002, SIRCA 052, 407. USA. California: 2006, CBHR 664, 658; 2006, CBHR 665, 499; 2006, CBHR 666, 658; 2006, CBHR 667, 658; 2006, CBHR 669, 658. Oregon: 2006, CBHR 1075, 658; 2006, CBHR 1076, 658; 2006, CBHR 1077, 658. Unknown State: unknown year, CBHR 171, 658.
Additional Notes
Species excluded from the New World Siricidae
Sirex juvencus Linnaeus, 1758 has been commonly accepted as an established species in North America (Benson 1943, 1945 and 1963; Smith 1979). However, the species is not established though it has been intercepted at many sea ports in the United States and Canada. The species is a well known traveler; it also was often intercepted in New Zealand (FRNZ, NZAC and PANZ), Australia, and the Philippines. The range of S. juvencus in the Old World is said to extend from Europe to Asia, but we have seen specimens only from Europe. The few specimens seen by us and labeled with this name in Asia are not S. juvencus. In the New World, this species is clearly segregated on ovipositor pits size (pits size similar to those seen at middle of lancet in S. nitidus, but pits only slightly smaller on basal annuli) and flagellum color pattern. The main hosts of S. juvencus are various species of Picea. These hosts do not occur around most ports in eastern North America where the species was intercepted.
A specimen from one interception in the United States was even described as a new species, S. hirsutus Kirby, 1882. Surprisingly, the male type (BMNH) is typical in all details with those of the European S. juvencus. Though this type specimen did not have a locality label, Kirby (1882: 380) believed that it was probably from “Georgia”. If so, there was no host for S. juvencus on the coast that that it could not have reproduced on so it could have become established. Sirex hirsutus is a NEW SYNONYM of the European S. juvencus.
Xeris spectrum has been commonly accepted as an established species in North America (Maa 1949, Ries 1951, Smith 1979, Schiff et al. 2006). However, it is not established, though it has been intercepted several times at various sea ports in the United States and New Zealand (specimens studied by us (FRNZ and USNM)). The range of X. spectrum extends from the Atlantic to the Pacific coasts in at least boreal regions of Eurasia (Maa 1949). The Nearctic species consists of two species, X. caudatus and X. melancholicus, and adults are distinguished from those of the X. spectrum complex by color pattern in both sexes and pit development on the ovipositor.
A name for the European “S. cyaneus”
The name S. cyaneus has long been used in Europe (Benson 1943) for a species presumed to be introduced from North America. The species does not match the North American S. cyaneus (see “Taxonomic notes” under Sirex cyaneus Fabricius). Based on the ovipositor character states, this species is close to S. nitidus and S. atricornis (see “Taxonomic notes” under S. nitidus) but does not match them or other Central European species of Sirex. Because the species is well represented in Central Europe and has been often intercepted at sea ports of North America and New Zealand, it is important to have a name for this species. We studied about 40 specimens from SDEI, FRNZ, PANZ and USNM. We tried to find a described species within the range of S. juvencus and S. noctilio that matches the species (which is, in fact, European, not North American) and found three: S. torvus M. Harris, 1779: 96 + plate 28 (figure 1 under Sirex), S. duplex Shuckard, 1837: 631, and S. leseleuci Tournier, 1890: 200. Sirex torvus is the oldest name for the European “S. cyaneus”.
For reasons mentioned above (“taxonomic notes” under S. cyaneus and S. nitidus) and the probable loss of the syntypes from the collection containing S. torvus (Evenhuis 1997) [ICZN 75(d) (4)], a neotype for S. torvus is required [ICZN 75(a), 75(d) (3)]. Even though the original illustration (Fig. D2.1) and description of the female are sufficiently diagnostic to distinguish the species from other species in Central Europe, S. torvus is extremely similar to the subarctic European S. atricornis and the North American S. nitidus. The neotype female, here designated, is deposited in SDEI [ICZN 75(d) (6)]. It is labeled as follows:
- [White and black outline] Schwäbische Alp Plettenberg bei Dottenhausen 7.VIII, 1976 Lauterbach leg.
- [White label and black outline] Paururus (♀) noctilio F. 6.79 P. Westrich det.
- [White and black outline] Sirex cyaneus Fabr. E.Jansen det.’ 93
- [Red] NEOTYPE (♀) Sirex torvus M. Harris Des. H. Goulet, 2011
[ICZN article 75(d) (2)]. The neotype is perfect except for the broken off right flagellum. Its type locality is from Germany as entered above [ICZN 75(f)]. Because S. torvus females and males may be confused with two other Central European species of Sirex (S. juvencus and S. noctilio), they are distinguished from these briefly here to satisfy ICZN 75(b) (3). Females of S. torvus, including the neotype (Fig. D2.2, neotype), are distinguished from S. juvencus by their black antenna and long ovipositor sheath (M. Harris 1779), and from S. noctilio by their very long ovipositor sheath (length of sheath portion beyond apex of cornus as long as combined length of terga 9 and 10) (Chrystal 1928) [ICZN article 75(d) (1)].
The synonymy is as follows:
- Sirex torvus M. Harris, [1779]: 96, plate 28 [for publication year see Evenhuis 1997 and Blank et al. 2009].
- Sirex duplex Shuckard, 1837: 631. Syntypes: 43 males and females (reared from Pinus nigra [now known as Picea mariana – information from P. Catling and G. Mitrow]), not seen. Shuckard’s collection was auctioned off by T. Desvignes and J. C. Stevens in London in 1868 soon after Schukard’s death (Horn et al., 1990: 364). Syntype depository unknown and specimens assumed lost. NEW SYNONYM. Type locality: “Cambridgeshire”.
- Sirex Leseleuci Tournier, 1890: 200. Syntypes presumed lost, not seen. NEW SYNONYM. Type locality: “Douarnenez, France”.
- Sirex cyaneus; Benson, 1943: 38 (not Fabricius, 1781: 419).
Mitochondrial DNA Results
Although a large part of this work is a classical morphological revision of the New World Siricidae, DNA barcoding analysis was used to identify potential new species and develop a method to identify siricid larvae.
DNA barcoding as used here was originally proposed by Hebert et al (2003) as “a new approach to taxon identification.” They postulated that if we wished to identify extant biodiversity we needed a faster, easier system than classical morphological methods and proposed that animal species could be uniquely identified by an approximately 600 base pair DNA sequence (barcode) of the mitochondrial Cytochrome Oxidase 1 gene. The advantages of barcode analysis included that it was fast, inexpensive, the characters are relatively uniform and unbiased, the analysis is quantitative, it can be used on all life stages, and it requires no specialized taxonomic experience or knowledge.
Since the proposal of Hebert et al. in 2003, barcodes have been used to identify animals including birds, fish and arthropods, discover cryptic species and associate life stages (Hajibabaei et al. 2006, Hebert et al. 2004, Hebert et al. 2004A, Hogg and Hebert 2004, Ball and Armstrong 2006, Smith et al. 2006, Ward 2005). However, as more studies were published, theoretical and practical difficulties were used to challenge the use of DNA barcodes alone for new species identification and classification (summarized in Rubinoff et al. 2006). These issues included heteroplasmy, where more than one mitochondrial haplotype is present in an individual (Frey and Frey 2004); numts (Lopez et al. 1994) where a nuclear pseudogene of mitochondrial origin was sequenced instead of the mitochondrial gene itself (Song et al. 2008, Pamilo et al. 2007, Koutroumpa et al. 2009); hybridization or indirect selection resulting from organisms like Wohlbachia mediating mitochondrial introgression in closely related species (Whitworth et al. 2007, Linnen and Farrell 2007, 2008); effects related to the biology of mitochondria such as reduced population size, maternal inheritance and limited recombination; and, finally, how much genetic distance should be used to delimit species (see Rubinoff et al. 2006 and the references therein). These limitations made it very difficult to use DNA barcoding as an easy alternative to classical or more sophisticated molecular methods for identifying new species. However, DeSalle (2006) in a rebuttal to Rubinoff et al. (2006) made a distinction between “species discovery” and “species identification.” He argued that using barcodes alone for species discovery was indeed rife with difficulties, but that once a set of barcodes was established for a group of species, unidentified specimens could be identified with the caveat that some specimens might not be resolvable. He suggested that a novel barcode sequence should be viewed as only a new species hypothesis to be tested and verified with more established methods. Although this resolution does not solve the challenge of how to recognize the vast number of undescribed species in the world, with our combined morphological and barcoding approach, it should allow us a means to identify adults and thus immature stages of New World Siricidae.
As with many groups of Hymenoptera, there are no morphological keys to immature stages of Siricidae, for several mostly practical reasons. First, until recently, there has been no pressing need for morphological keys to siricid larvae. Sirex noctilio, the most significant siricid pest, has only been an economic pest in conifer plantations in the Southern Hemisphere where there were no native woodwasps to confuse it with (Hoebeke et al. 2005). Second, rearing larvae from trees is costly and time consuming. Locating, harvesting and storing infested trees is labor intensive and because many species of woodwasps take up to several years to attain maturity it is quite time consuming and thus expensive. Third, until this manuscript, most woodwasps were not considered to be particularly host specific and because many species can attack the same host it was not easy to associate specific larvae with reared adults.
The primary reasons to identify larvae are to recognize an infestation of a pest species and to prevent further introductions of exotic species. As the larval stage is present for 11 months and adults are only present for a few weeks it would be advantageous to be able to identify larvae immediately using molecular methods (hours or days) rather than wait as much as a year or more until identifiable adults can be reared. Because DNA is the same for all life stages, a molecular technique that identifies adults will also identify immature life stages.
Results of DNA analysis
The 622 specimens of woodwasps sequenced were resolved into 31 taxa including 28 taxa of Siricidae (603 sequences) and one taxon each of Xiphydriidae (Xiphydria mellipes, 3 sequences), Syntexidae (Syntexis libocedrii, 12 sequences) and Orussidae (Orussus thoracicus, 4 sequences) (Fig. E2.1). Complete consensus sequences, 658 base pairs, were obtained for 29 of the 31 taxa ultimately resolved. The consensus sequences for Sirex obesus and Sirex near californicus were only 613 and 615 base pairs, respectively. Of the 622 specimens sequenced, 476 (76.5%) were complete sequences; of the rest, 88 specimens were greater in length than 600 base pairs, 48 were longer than 500bp, 6 were longer than 400bp and 4 were longer than 300bp. Length of sequence for individual specimens is recorded under each species description. All species except Sirex obesus and Sirex near californicus had at least one specimen with a full length sequence.
Although all 622 specimens were unambiguously assigned to the correct family, genus and species/taxon according to the siricid family revision proposed here, when this work was started, under the former classification (summarized in Smith 1979, Smith and Schiff 2002, Schiff et al. 2006), barcoding results generated several new species level hypotheses. In two cases, one in Xeris and one in Sirex, pairs of what were considered to be good species or subspecies were found to share identical barcodes. What were formerly classified as Sirex nigricornis and S. edwardsii are now listed as S. nigricornis and what were formerly listed as Xeris spectrum townesi and X. morrisoni indecisus are now listed as X. indecisus. Further, two pairs of subspecies, X. morrisoni morrisoni and X. morrisoni indecisus, and Urocerus gigas gigas and U. gigas flavicornis were easily separated using barcodes and are now elevated to species as Xeris indecisus, X. morrisoni, Urocerus gigas and U. flavicornis, respectively. DNA barcodes also hypothesized or supported several new taxa. Sirex abietinus was a single novel sequence until the species was characterized morphologically and more specimens were obtained and sequenced. Xeris melancholicus was initially recognized by its unique barcode and then characterized morphologically. Sirex obesus was identified morphologically and then, when fresh specimens were obtained and sequenced, supported by barcodes. Two other taxa, Sirex near nitidus and especially Sirex near californicus are recognized by barcodes but have not been assigned species names because we have been unable to find supporting morphological characters with so few specimens.
The neighbor-joining tree of consensus sequences of each taxon (Fig. E2.1) showed well-delimited taxa. Separate neighbor-joining trees (Figs. E2.2, E2.3, E2.4a, E2.4b, E2.4c, E2.5a, E2.5b, E2.5c, E2.5d, E2.5e and E2.5f) for individual specimens of small groups of species showed low intra-specific and high inter-specific divergence with no overlap between species. Percent identity and divergence for consensus sequences of all taxa are presented in Table E2.6. The greatest divergences were between families of woodwasps (30–40%). Anaxyelidae was most divergent from the others (34.1%–45.5%) followed by Orussidae (30.5%–42.6%) and Xiphydriidae (30.5%–40.3%). Within the Siricidae, the genera were well defined with percent divergences in the 20s–30s and within genera as low as 1.7% to the 20s. Divergences for the closest pairs of taxa were 1.7% for Sirex nitidus and S. near nitidus, 2.2% for Xeris indecisus and X. morrisoni, 2.8% for Urocerus gigas and U. flavicornis, 3.3% for Xeris caudatus and X. melancholicus, 4.6% for Sirex abietinus and S. varipes, 5.1% for Sirex californicus and S. near californicus and approximately 3.7% for Sirex cyaneus and S. nitidus or S. near nitidus. Of these least divergent pairs the smallest and largest divergences were for pairs that lacked morphological support.
Discussion
The most important question when deciding to use a new technique to identify species is: does the technique unambiguously identify specimens of each species correctly 100% of the time? In the case of using DNA barcodes to identify New World Siricidae the answer is yes but it was difficult to get to this answer because the Siricidae was in need of revision when the project was started. Our simultaneous morphological and barcoding analyses are in almost complete agreement. Unique barcodes exist for all morphologically distinct species for which we could obtain sequences. However, two of the morphologically distinct species, Sirex californicus and S. nitidus, each appear to harbor a cryptic taxon that is only recognizable by DNA barcode. The question remains: are these cryptic taxa good species? It is possible they could be artifacts of barcoding such as heteroplasmy or numts or it may be they are very good cryptic species and we have been unable as yet to discover morphological or behavioral support for them. To reduce the risk of heteroplasmy we directly sequenced double stranded PCR products. If there were rare haplotypes they would be masked by the most common haplotype. If there were two or more common haplotypes there would have been double peaks and the sequences would have been difficult to read. To reduce the possibility of having amplified numts we isolated samples from mitochondrial rich tissue and we inspected translated sequences to look for artifacts common in numts such as stop codons, insertions and deletions. There were no stop codons, insertions or deletions in any of the samples except for Orussus thoracicus which was missing one codon, in frame. We do not believe this is indicative of a nuclear mitochondrial pseudogene however, as the same codon is absent in three other Orussus species (data not presented). Either, all four Orussus species have the same pseudogene which is amplified preferentially over the mitochondrial gene, which seems unlikely, or the missing codon reflects a genuine difference between Orussus and all the other woodwasps. Although we believe the cryptic taxa are probably valid species, until we can examine more specimens and do further analyses we have chosen to leave the cryptic taxa unnamed. Despite the utility of barcodes for identifying Siricidae we still believe new species require a morphological description.
One of the reasons barcoding was so useful in revising the North American Siricidae is because it is color blind. Prior to this study, abdomen and leg color were often used as simple diagnostic characters for siricid species (Middlekauf 1960, Smith and Schiff 2002, Schiff et al. 2006). However, identical DNA barcodes supported by morphological characters suggested that pairs or groups of what were considered to be good species based on abdomen color were really single species. In this study there were three examples, Sirex nigricornis, Xeris indecisus and Tremex columba. In the first two examples, each species has two female color morphs with either red (the former Sirex nigricornis and the former Xeris morrisoni indecisus) or black (the former Sirex edwardsii and the former Xeris spectrum townesi) abdomens. In the third example, females of T. columba have one of three color morphs associated with wing color differences. These color morphs were recognized as separate species until Bradley (1913) lumped them together, a position supported by the current barcode results. Whereas it is easy to understand why such dramatic characters would be considered diagnostic for species, this study demonstrates that abdomen color can be misleading. Interestingly, in the original description Brullé suggested that the only difference he saw between Sirex edwardsii and Sirex nigricornis was that the abdomen was blue and he even suggested that it might just be a variety of Sirex nigricornis. Genetic control of abdomen color must be fairly loose in Symphyta because there are several examples of different color morphs in at least four different families. Species with both red and black abdominal color morphs have been recorded in the Xiphydriidae (Xiphydria tibialis Say, in Smith 1976), Xyelidae (Macroxyela ferruginea (Say), in Smith and Schiff 1998), Tenthredinidae (Lagium atroviolaceum (Norton), in Smith 1986) and, Siricidae (present study). Barcodes were also useful in resolving leg color morphs. Sirex californicus, S. nitidus and S. noctilio each have pale and dark leg color morphs. At least for Sirex californicus and S. nitidus both color forms have the same barcode. We have no sequences for the dark color morph of Sirex noctilio. Ironically, abdomen and leg color are still useful characters for identifying woodwasps (e.g., Sirex varipes) but this work shows that they should not be used as sole diagnostic characters. Instead, they should be combined with other characters, as we do here, to lead to a diagnosis.
To identify any stages of woodwasps using barcodes, a novel sequence should be aligned with the 31 consensus sequences reported here (See appendix 3) using Clustal V and then visualized in a neighbor-joining tree using appropriate software. The novel sequence should align very closely with the branch of its congener. The range of intra-specific variation is represented in the species trees (Figs. E2.2, E2.3, E2.4a, E2.4b, E2.4c, E2.5a, E2.5b, E2.5c, E2.5d, E2.5e and E2.5f) and it should be easy to recognize if a species falls outside its expected range. Determining a species threshold limit for barcode data of unknown taxa is quite controversial (Rubinoff et al. 2006). Hebert et al. (2003) originally proposed that a 2-3% difference would be sufficient to separate animal species. At that level, we might not be able to separate Sirex nitidus from the cryptic taxon S. near nitidus, or two pairs of closely related but morphologically distinct species, Urocerus flavicornus from U. gigas and Xeris morrisoni from X. indecisus. Later, Hebert et al. (2004A) proposed a threshold that was 10 times the mean intraspecific variation for the group under study. This new threshold addresses the diagnostic value of the relationship of interspecific to intraspecific variation but still presupposes a level of species uniformity. Both of these thresholds could be problematic if we were trying to separate species from a sea of unknowns; fortunately, we are trying to identify unknowns by comparison to a relatively well sampled database of recognized species. Unknown sequences will either match one of the known species or become a new hypothesis to be evaluated with morphological or other methods. Although all the species represented here are well delimited, it is possible that barcodes for newly recognized, closely related species could overlap and this database would not be able to resolve them.
We believe the consensus tree (Fig. E2.1) is robust because of the species sampling that went into it. We obtained representatives of each species from as much of the geographic and temporal ranges as possible, as can be seen in the specimens for molecular studies section under each species description. Although sampling can never be complete, multiple samples across the range are a more cogent representation of the species variation then a single specimen from one location in its range.
Conclusion
The combination of classical morphological and DNA barcoding methods have allowed us to revise New World Siricidae and develop a DNA database that will enable identification of most New World siricid larvae. Each morphological species has a corresponding well-delimited barcode. Two species appear to have a cryptic taxon which we have chosen to keep unnamed because they lack morphological support. Our work demonstrates that barcodes are a useful addition to other taxonomic methods, especially for tasks such as associating life stages.
Orussus thoracicus:
USA. California: 2005, CBHR 35, 655; 2005, CBHR 306, 655; 2005, CBHR 307, 655; 2005, CBHR 308, 655.
Syntexis libocedrii:
USA. California: 2005, CBHR 86, 658; 2005, CBHR 87, 658; 2005, CBHR 88, 658; 2005, CBHR 89, 658; 2005, CBHR 90, 658; 2005, CBHR 91, 658; 2005, CBHR 92, 658; 2005, CBHR 93, 658; 2005, CBHR 94, 658; 2005, CBHR 95, 658. Oregon: 2003, CBHR 7, 658; 2003, CBHR 9, 658.
Xiphydria mellipes:
CANADA. Ontario: 2005, CBHR 1055, 658; 2005, CBHR 1095, 658. USA. Wisconsin: 2005, CBHR 149, 658.
Acknowledgments
Many colleagues generously contributed various elements that helped us producing a comprehensive revision. We are most appreciative of and indebted for their support.
Systematic research is based on specimens stored in collections and looked after by conscientious colleagues. The quality of research is proportional to the number of specimens studied. We were fortunate to obtain a large number of them and are most thankful to the curators mentioned under “materials and methods” that either facilitated our visit to their collection or sent us specimens on loan. With the establishment of Sirex noctilio in the Great Lake region, many surveys were carried out and long series of specimens were submitted to us for identification. We greatly appreciate the survey specimens of Siricidae generously given to us by H. Douglas (CFIA), D. Langor (NFRC), the late P. de Groot, K. Nystrom and I. Ochoa (GLFC), L. Humble and J. Smith (PFRC), J. J. Jones (Alberta), J. Kruze (USFS–AK), D. Miller (USFS–GA), C. Piché (MNRQ), J. Sweeney and J. Price (FRLC), and K. Zylstra (USDA). These fresh and clean specimens permit us to study the DNA of significant specimens and did enrich our collections.
We would like to thank A. Abel, A. Lancaster, C. Oberle, and C. Wilkins for assistance in the lab and with rearing specimens and the following who helped either with specimens or in the field: I. Aguayo, M. Allen, R. Bashford, L. Bezark, C. Brodel, M. Chain, K. Cote, D. Crook, E. Day, Y. DeMarino, P. Denke, D. Duerr, the Fish family, H. Hall, D. Haugen, S. Heydon, R. Hoebeke, B. Hofstrand, A. Horne, L. Humble, W. Johnson, V. Klasmer, R.L. Koch, B. Kondratief, J. Kruse, J. Labonte, P. Lago, E. Lisowski, V. Mastro, S. McElway, H. McLane, J. Meeker, D. Miller, A. and G. Mudge, D. Patterson, T. Price, J. Quine, L. Reid, V. Scott, C. Snyder, S. Spichiger, W. Tang, P. Tolesano, M. Ulyshen, M. Vardanega, G. Varkonyi, S. Vaughn, J. Vlach, and R. Westcott.
Traditionally, only morphological features were studied from specimens in collections. Lately, DNA sequencing of properly preserved specimens has opened a new set of characters previously unavailable. Many of the submitted specimens were freshly collected and offered us the opportunity to extract information from DNA barcode (cytochrome c oxydase 1 – CO1). This new tool in conjunction with the classical morphological approach gave us much confidence in our conclusions. We greatly appreciate having access to specimens properly preserved for DNA sequencing provided by H. Douglas (CFIA), V. Grebennikov (CFIA), D. Langor (NFRC), P. de Groot, K. Nystrom and I. Ochoa (GLFC), L. Humble and J. Smith (PFRC), and D. Miller (USFS–GA). We are also very grateful for support from the Government of Canada through Genome Canada and the Ontario Genomics Institute in support of the International Barcode of Life Project. This funding allowed staff at the Biodiversity Institute of Ontario under the leadership of P. Hebert to sequence more than 300 specimens of Siricidae, and covered the costs in the preparation and digitization of specimen data by J. Fernandez–Triana. We also appreciate the time spent by A. Smith and J. Fernandez–Triana explaining details of the results to HG.
We intended this work to be profusely illustrated. We had access to lots of dried adults, but we wanted to show how they looked when alive. Unless properly equipped, finding live specimens of Siricidae is often difficult. We therefore thank P. de Groot (GLFC), J. Sweeney and J. Price (FRLC), and K. E. Zylstra (USDA) for providing live specimens of some species of Siricidae or their parasitoids for live habitus images. We also appreciated movies of parasites and Siricidae provided by J. Read (CNC).
Adults of Siricidae are easily damaged so we were worried about borrowing type specimens. We tried to study types during our visit to various North American collections but we did not have the opportunity to visit European collections. To avoid having types sent by post, we studied the description and previous opinions about each type. Then, we decided if photos of a type would be enough to resolve its identity. Through the kindness of G. Hancock (HMUG), J. E. Hogan (OXUM), L. Vilhelmsen (ZMUC), we were able to get the necessary pictures taken.
Much information came from many colleagues. The following colleagues kindly spent time trying to find specimens of unusual species in their respective collections, providing information about types whereabouts, and hand carrying of such specimens. We are very grateful to C. P. D. T. Gillett (BMNH), H. Vardal (Swedish Museum of Natural History), Y. Bousquet (CNC), V. Grebennikov (CFIA), G. Hancock (HMUG), J. Karlson (Swedish Malaise Trap Project), J. Genaro (Toronto, Ontario), M. Sharkey (Kentucky), A. Shinohara (EIHU) for their efforts. Because of widespread surveys around the Great Lakes, we had access to records of numerous locations for each species. We greatly appreciate not only the data but the coordinates, allowing us to map rapidly the range of many species within the survey area. For this information we are indebted to R. Favrin and L. Dumouchel (CFIA), R. Hoebecke (CUIC), S. Long (CUIC), K. Nystrom (GLFC), and C. Piché (MNRQ). Preparing this paper for the internet involves new knowledge with new software programs. We are most grateful for the training provided by J. Read (CNC) to C. Boudreault (CNC) and her help in designing various templates. In addition we thank L. Bearss (CNC) for training C. Boudreault in the use of a mapping program. When problems arise there is nothing better than your closest colleagues to discuss them. We are much indebted to S. M. Blank (SDEI), L. Masner (CNC), A. Hajek (CUIC), and J. T. Huber (CNC). Sometimes questions go beyond Siricidae and even insects. We greatly appreciate detailed information provided by our esteemed botanical colleagues P. Catling and G. Mitrow (National Collection of Vascular Plants, Department of Agriculture, Ottawa), about the nomenclatural history of the black spruce as used in Europe in the first half of the 19th century. Finally, we thank the late R. Roughley (EDUM), G. E. Ball and D. Shpeley (UASM) for courtesies extended during our visits to their respective establishments.
At completion of a large manuscript, it is very difficult to see one's own errors in the text. Despite our efforts we missed numerous punctuation, grammatical mistakes, overly long sentences, sentences with missing words, and duplication of part of sentences during copy and paste work. We are most thankful to reviewers, G. A. P. Gibson, J. T. Huber, S. Blank, A. Liston, A. Taeger, R. A. Ochoa, T. J. Henry, and S. A. Marshall. We are especially thankful to J. T. Huber who read the text very critically three times. He rounded up most errors and insured a uniformity of style.
We would also like to thank the managers and staff for use of the following natural areas: Yazoo National Wildlife Refuge, Dahomey National Wildlife Refuge, Delta National Forest, Crossett Experimental Forest, Delta Experimental Forest.
This project was supported by a Forest Health Protection, Special Technology Development Program Grant to N. M. Schiff and A. D. Wilson, and a CANACOLL Collection improvement grant to work on Siricidae in the Canadian National Insect Collection, Ottawa, Canada to N. M. Schiff.
References
Aguiar, A. P. and Johnson, N. F. 2003. Stephanidae (Hymenoptera) of America North of Mexico. Proceedings of the Entomological Society of Washington 105(2): 467-483.
Allard, G. 2008a. Overview of forest pests in Argentina. Forest health and biosecurity working papers. Forest Department. Food and Agriculture Organization of the United Nations. Working paper FBS/9E, Rome, Italy. 22 pp.
Allard, G. 2008b. Overview of forest pests in Chile. Forest health and biosecurity working papers. Forest Department. Food and Agriculture Organization of the United Nations. Working paper FBS/12E, Rome, Italy. 30 pp.
Allen, R. R. and Ball, G. E. 1980. Synopsis of Mexican taxa of Loxandrus series (Coleoptera: Carabidae: Pterostichini). Transactions of the American Entomological Society 105: 481-576.
Amman, G. D. 1969. Annotated list of insects infesting bark and wood of Fraser fir. Journal of Economic Entomology 62: 249-250.
Ashmead, W. H. 1898. Classification of the horntails and sawflies, or the sub-order Phytophaga (Paper No. 2). The Canadian Entomologist 30: 177-183.
Ashmead, W. H. 1900. Order Hymenoptera. Pp. 501-613, in Smith J. B. Insects of New Jersey: a list of species occurring in New Jersey with notes on those of economic importance. MacCrellish and Quigley, Trenton, New Jersey. 755 pp.
Ashmead, W. H. 1904. Descriptions of four new horn-tails. The Canadian Entomologist 36: 63-64.
Baldini, U. A. 2002. Tremex fuscicornis: Un factor de daño para el recurso Forestal y Agrícola. Agronomia y Forestal UC, Revista de Extension de la Facultad de Agronomía e Ingenieria Forestal de la Ponteficia, Universidad Católica de Chile, Santiago 16: 11-13.
Ball, S. L. and Armstrong, K. F. 2006. DNA barcodes for insect pest identification: a test case with tussock moths (Lepidoptera: Lymantriidae). Canadian Journal of Forest Research 36: 337–350.
Baumberger, J. P. 1915. Notes on the Siricidae of California (Hym.). Entomological News 26: 34.
Beal, J. A. and Massey, C. L. 1945. Bark beetles and ambrosia beetles (Coleoptera: Scolytoidea): with special reference to species occurring in North America. School of Forestry. Bulletin 10: 1-178.
Bedard, W. D. 1938. A annotated list of the insects fauna of Douglas fir (Pseudotsuga mucronata Rafinesque) in the northern Rocky Mountain region. The Canadian Entomologist 70: 188-197.
Bedding R. A. 1967. Parasitic and free-living cycles in entomogenous nematodes of the genus Deladenus. Nature 214: 174–175.
Bedding R. A. 1972. Biology of Deladenus siricidicola (Neotylenchidae) an entomophagous-mycetophagous nematode parasitic in siricid woodwasps. Nematologica 18: 482–493.
Bedding R. A. 1974. Five new species of Deladenus (Neotylenchidae), entomophagous-mycetophagous nematodes parasitic in siricid woodwasps. Nematologica 20: 204–225.
Bedding R. A. and Akhurst, R. J. 1978. Geographical distribution and host preferences of Deladenus species (Nematoda: Neotylenchidae) parasitic in siricid woodwasps and associated hymenopterous parasitoids. Nematologica 24: 286–294.
Bedding R., Iede, E. 2005. Application of Beddingia siricidicola for Sirex woodwasp control. pp. 385–399, in: P.S. Grewal, R.-U. Ehlers and D.I. Shapiro-Ilan (eds.). Nematodes as Biocontrol Agents. Publisher, London, UK.
Belyea, R. B. 1952. Death and deterioration of balsam fir weakened by spruce budworm defoliation in Ontario. The Canadian Entomologist 84: 325-335.
Benson, R. B. 1938. On the classification of sawflies (Hymenoptera, Symphyta). Transactions of the Royal Entomological Society of London 87: 353- 384.
Benson, R. B. 1940. Sawflies of the Berkhamsted district: with a list of the sawflies of Hertfordshire and Buckinghamshire, and a survey of the British species (Hymenoptera, Symphyta). Transactions of the Hertfordshire Natural History Society and Field Club 21(3): 177-231.
Benson, R. B. 1943. Studies in Siricidae, especially of Europe and southern Asia (Hymenoptera, Symphyta). Bulletin of Entomological Research 34: 27-51.
Benson, R. B. 1945. Urocerus californicus (Norton) and some other interesting Siricidae (Hym., Symphyta) in Britain. Entomologist's Monthly Magazine 81: 67-68.
Benson, R. B. 1962. Holarctic sawflies (Hymenoptera: Symphyta). Bulletin of the British Museum (Natural History) Entomology 12: 381-409.
Benson, R. B. 1963 (1962). A character gradient in Sirex juvencus L. (Hym., Siricidae). Entomologist's Monthly Magazine 98: 252-253.
Blackman, M. W. and Stage, H. H. 1918. Notes on insects bred from the bark and wood of the American larch – Larix laricina (Du Roc) Koch. Technical Publication No. 10 of New York State College of Forestry at Syracuse University. 115 pp.
Blackman, M. W. and Stage, H. H. 1924. On the succession of insects living in the bark and wood of dying, dead and decaying hickory. Technical Publication No. 17 of New York State College of Forestry of Syracuse University. (Vol. 24, No. 22).
Blank, S. M., Taeger, A., Liston, A. D., Smith, D. R., Rasnitsyn, A. P., Shinohara, A., Heidemaa, M. and viitasaari, M. 2009. Studies toward a World Catalog of Symphyta (Hymenoptera). Zootaxa 2254: 1-96.
Bordage, E. 1914. Notes biologiques recueillies à l'Ile de la Réunion. Bulletin Scientifique de la France et de la Belgique. Paris 47(4) (in Review of Applied Entomology 2 p. 215).
Böröczky, K., Crook, D. J., Jones, T. H., Kenny, J. C., Zylstra, K. E., Mastro, V. C. and Tumlinson, J. H. 2009. Monoalkenes as contact sex pheromone components of the woodwasp Sirex noctilio. Journal of Chemical Ecology 35: 1202–1211.
Bradley, J. C. 1913. The Siricidae of North America. Journal of Entomology and Zoology 5: 1-35.
Bradley, J. C. 1934. A new species of Xeris (Hymenoptera, Siricidae) from the Himalayas. Records of the Indian Museum, Calcutta 36(2): 145.
Brullé, A. 1846. Histoire naturelle des Insectes. Hyménoptères. (ed. Lepeletier de Saint-Fargeau), Paris. Vol. 4, 680 pp.
Buchner, P. 1928. Holznährung und Symbiose. J. Springer, Berlin.
Burks, B. D. 1958. Symphyta. Pp. 8-18, in Krombein, K. V. (ed.). Hymenoptera of America North of Mexico, Synoptic Catalog, First Supplement (Agricultural Monograph No. 2), United States Department of Agriculture, Washington, D.C. 305 pp.
Burks, B.D. 1967. Symphyta. Pp. 6-27, in Krombein, K. R. and B. D. Burks (eds.). Hymenoptera of America North of Mexico, Synoptic Catalog. Second Supplement (Agricultural Monograph No. 2), United States Department of Agriculture, Washington, D.C. 584 pp.
Cameron, E. A. 1965. The Siricinae (Hymenoptera: Siricidae) and their parasites. Technical Bulletin, Commonwealth Institute of Biological Control 5: 1-31.
Cameron, E. A. 1967. Notes on Sirex juvencus californicus (Hymenoptera: Siricidae), with a description of the male and a key to the California species of Sirex. The Canadian Entomologist 99: 18-24.
Cameron, E. A. 1968. Sirex juvencus californicus in smog-killed trees in Southern California (Hymenoptera: Siricidae). Pan-Pacific Entomologist 44: 168.
Cameron, P. 1883-1890. Siricidae. Pp. 68-69, in Biologia Centrali-americana. Insecta Hymenoptera (families Tenthredinidae – Chrysidiade). Vol. I [the Siricidae were published in 1883.]
Cameron, P. 1890. Monograph of British phytophagous hymenoptera. Vol. 3: 134. The Ray Society, London. 274 pp. + 17 pls.
Cartwright, K. St G. 1929. Notes on a fungus associated with Sirex cyaneus. Annals of Applied Biology 16: 182–187.
Cartwright, K. St G. 1938. A further note on fungus association in Siricidae. Annals of Applied Biology 25: 430–432.
Chamberlin W. J. 1949. A note on Sirex areolatus (Cresson) (Hymenoptera, Siricidae). Pan-Pacific Entomologist 25: 118.
Champlain, A. B. 1922. Records of hymenopterous parasites in Pennsylvania. Psyche 29: 95–100.
Chapin, J. B. and Oliver, A. D. 1986. Records of Eriotremex formosanus (Matsumura), Sirex edwardsii Brullé, and Neurotoma fasciata (Norton) in Louisiana (Hymenoptera: Siricidae, Pamphiliidae). Proceedings of the Entomological Society of Washington 88: 190.
Chapman, J. A. 1954. Studies on summit-frequenting insects in western Montana. Ecology 35(1): 41-49.
Chapman, R. F. 1982. The Insects: Structure and Function. Harvard University Press, Cambridge, MA. 919 pp.
Champlain, A. B. 1922. Records of hymenopterous parasites in Pennsylvania. Psyche 29: 95-100.
Christ, J. L. 1791. Naturgeschichte, Klassification und Nomenclatur der Insekten vom Bienen, Wespen und Ameisengeschlecht; als der fünften Klasse fünfte Ordnung des Linneischen Natursystems von den Insekten: Hymenoptera. Mit häutigen Flügeln. Frankfurt. 535 pp.
Chrystal, R. N. 1928. The Sirex woodwasps and their importance in forestry. Bulletin of Entomological Research 19: 219-247.
Chrystal, R. N. 1930. Studies of the Sirex parasites. Oxford Forestry Memoirs 11, 63 pp.
Chrystal, R. N. and Myers, J. G. 1928a. Natural enemies of Sirex cyaneus Fabr., in England and their life history. Bulletin of Entomological Research 19: 67-77.
Chrystal, R. N. and Myers, J. G. 1928b. The Sirex woodwasps and their parasites. Empire Forestry Journal 7: 145-154.
Ciesla, W. M. 2003. Exotic Forest Pest Information System for North America: Tremex fuscicornis. North American Forest Commission. http://spfnic.fs.fed.us/exfor/data/pestreports.cfm?pestidval=157&langdisplay=english (accessed on November 1, 2011)
Clark, A. F. 1933. The horntail borer and its fungal association. New Zealand Journal of Science and Technology 15: 3.
Clementi, V. 1868. Capture of Tremex columba. The Canadian Entomologist 1(4): 29.
Cockerell, T. D. A. 1889. Colorado Biological Association. Report 10: 37.
Cooley, R. A. 1896. A new structural character in insects. Psyche 7: 395-397.
Costa, A. 1894. Prospetto degli Imenotteri Italiani. III, Tenthredinidei e Siricidei. Atti della Reale Accademia delle Scienze Fisiche e Matematiche, Napoli, Vol. 3, 290 pp.
Coutts, M. P. 1965. Sirex noctilio and the physiology of Pinus radiata. Australian Department of National Development Forest and Timber Bureau. Bulletin 41: 3.
Coutts, M. P. 1969a. The mechanism of pathogenicity of Sirex noctilio on Pinus radiata I. Effects of the symbiotic fungus Amylostereum sp. (Thelophoraceae). Australian Journal of Science 30: 274–276.
Coutts, M. P. 1969b. The mechanism of pathogenicity of Sirex noctilio on Pinus radiata 2. Effects of the S. noctilio mucus. Australian Journal of Science 22: 915–924.
Coutts M. P. and Dolezal, J. E. 1965. Sirex noctilio, its associated fungus, and some aspects of wood moisture content. Australian Forestry Research 1: 3–13.
Coutts, M.P. and Dolezal, J. E. 1969. Emplacement of fungal spores by the woodwasp Sirex noctilio during oviposition. Forest Science 15: 412–416.
Couturier, A. 1949. Observations sur les Rhyssa approximator F. cleptoparasite de Rh. persuasoria L. (Hym. Ichneumonidae). Bulletin de la Société entomologique de France 54: 62-63.
Craighead, F. C. 1950. Insect enemies of the eastern forest. United States Department of Agriculture. Miscellaneous Publication No. 657: 586-587.
Cresson, E. T. 1865a. On the Hymenoptera of Cuba. Proceedings of the Entomological Society of Philadelphia 4: 1-4.
Cresson, E. T. 1865b. Catalogue of Hymenoptera in the collection of the entomological society of Philadelphia, from Colorado Territory. Proceedings of the Entomological Society of Philadelphia 4: 242-247.
Cresson, E. T. 1868. Catalogue of a small collection of Hymenoptera made in New Mexico during the summer of 1867. Transactions of the American Entomological Society 1: 375-388.
Cresson, E. T. 1880. Catalogue of the Tenthredinidae and Uroceridae of North America. Transactions of the American Entomological Society 8: 53-68.
Cresson, E. T. 1916. The Cresson types of Hymenoptera. Memoirs of the American Entomological Society, No. 1. 141 pp.
Cresson, E. T. 1928. The types of Hymenoptera in the Academy of Natural Sciences of Philadelphia other than those of Ezra T. Cresson. Memoirs of the American Entomological Society No. 5. 90 pp.
Crompton, G. C. 1919. The genitalia and terminal abdominal structures of males and the terminal abdominal structures of the larvae of chalastogastrous Hymenoptera. Proceedings of the Entomological Society of Washington 21(6): 129-155.
Curtis, J. 1829. British entomology; being illustrations & descriptions of genera of insects found in Great Britain and Ireland. Vol. VI. London. 289 pages and plates.
Dalla Torre, de C. G. 1894. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. Volume I : Tenthredinidae including Uroceridae (Phyllophaga & Xylophaga). G. Engelmann, Lipsiae [Leipzig, Germany]. 459 pp.
Daly, H. V. 1963. Close-packed and fibrillar muscles of the Hymenoptera. Annals of the Entomological Society of America 56: 295-306.
Davis, J. J. 1932. Insects of Indiana for 1932. Proceedings of the forty-eighth Annual Meeting. Indiana Academy of Science 42 : 213-225.
DeGeer, C. 1773. Mémoire pour server à l'histoire des insects. Tome 3ième. Pierre Hesselberg, Stockholm. VIII + 696 pp.
De Groot P., Nystrom K. and Scarr T. 2006. Discovery of Sirex noctilio (Hymenoptera: Siricidae) in Ontario, Canada. Great Lakes Entomologist 39: 49–53.
De Leon, D. 1952. Insects associated with Sequoia sempervirens and Sequoia gigantea in California. Pan-Pacific Entomologist 23: 75-91.
DeSalle, R. 2006. Species discovery versus species identification in DNA barcoding efforts: Response to Rubinoff. Conservation Biology 20: 1545–1547.
Dimmock, A. K. 1885. The insects of Betula in North America. Psyche 4: 271-286.
Drury, D. 1773. Illustrations of Natural History Wherein are exhibited Upwards of Two Hundred and Twenty Figures of Exotic Insects, According to their different Genera; Very few of which have hitherto been figured by any author, being engraved and coloured from Nature, with the greatest accuracy, and under the author's own inspection, on fifty copper-plates, with a particular description of each insect: Interspersed with remarks and reflections on the nature and properties of many of them. Vol. II. Printed by the author, London. vii + 90 + [2] + [2] pp., 50 pls.
Essig, E. O. 1926. Insects of Western North America. The MacMillan Company, New York. XII + 1035 pp.
Evenhuis, N. L. 1997. Litteratura taxonomica dipterorum (1758-1930). Vol. 1 (A-K) Vol. 2 (L-Z). Backhuys Publishers, Leiden. V11+ 871 pp.
Fabricius, J. C. 1781. Species Insectorum exhibentes eorum differentias specificas, synonyma auctorum, loca natalia, metamorphosin adiectis observationibus, descriptionibus. C. E. Bohnii, Hamburgi et Kilonii, Vol. 1, VIII + 552 pp.
Fabricius, J. C. 1787. Mantissa insectorum sistens eorum species nuper detectas adiestis characteribus, genericis, differentiis specificis, emendationibus, observationibus. Tome I. C. G. Proft, Hafniae. 20+348 pp.
Fabricius, J. C. 1793. Entomologica systematica emendata et aucta. Secundum classes, ordines, genera, species adjectis synonimis, locis, observationibus, descriptionibus. C. G. Proft, Hafniae. Vol. 2: 104-132.
Fattig, P. W. 1949. Some observations on Megarhyssa (Hymenoptera, Ichneumonidae). Entomological News 60: 69-71.
Felt, E. P. 1905. Insects affecting park and woodland trees. New York State Museum. New York State Education Department. Vol. I. 458 pp.
Felt, E. P. 1906. Less destructive insects affecting evergreen or conifer trees. Pp. 648-700, Insects affecting park and woodland trees. Memoir of the New York State Museum 8. 877 pp.
Fernandez-Triana, J., Smith, M. A., Boudreault, C., Goulet, H., Hebert, P. D. N., Smith, A.C. and Roughley, R. 2011. A poorly known high-latitude parasitoid wasp community: Unexpected diversity and dramatic changes through time. PLoS One 6(8): e23719. doi:10.1371/journal.pone.0023719
Fidalgo, P. and Smith, D. R. 1987. A fossil Siricidae (Hymenoptera) from Argentina. Entomological News 98: 63-66.
Fitch, A. 1857. Noxious and other insects of the State of New York. Transaction of the New York Agricultural Society 16: 349-490.
Fitch, A. 1858a. Noxious and other insects of the State of New York. Report 4: 1-67.
Fitch, A. 1858b. Noxious and other insects of the State of New York. Report 5: 1-74.
Fitch, A, 1859. Noxious and other insects of the State of New York. Insect infesting deciduous trees. Report 5: 781-854.
Flanders, S. E. 1925. Ibalia ensiger Norton on Monterey Cypress. Journal of Economic Entomology 18: 236-237.
Folmer, O., Black, M., Hoeh, W., Lutz, R. and Vrijenhoek, R. 1994. DNA primers for amplification of mitochondrial cytochrome c oxidase subunit 1 from diverse metazoan invertebrates. Molecular Marine Biology and Biotechnology 3: 294–299.
Forsius, R. 1933. Notes on a collection of Malaysian Tenthredinoidea (Hym.). Bulletin of the Raffles Museum 8: 169-193.
Francke-Grossmann, H. 1939. Über das Zusammenleben von Holzwespen (Siricinae) mit Pilzen. Zeitschrift für Angewandte Entomologie 25 (1938–1939) (4): 647-680.
Francke-Grosmann, H. 1954. Tierische Holzschädlinge, Holzwespen. Holz als Roh- und Werkstoff 12: 35-38.
Frey, J. E. and Frey, B. 2004. Origin of intra-individual variation in PCR-amplified mitochondrial cytochrome oxidase 1 of Thrips tabaci (Thysanoptera Thripidae): mitochondrial heteroplasmy or nuclear integration? Hereditas 140: 92–98.
Frison, T. H. 1927. List of the insect types in the collections of the Illinois State Natural History Survey and the University of Illinois. Bulletin of the Illinois State Laboratory of Natural History 16(4): 137-309.
Fukuda, H. and Hijii, N. 1997. Reproductive strategy of a woodwasp with no fungal symbionts, Xeris spectrum (Hymenoptera: Siricidae). Oecologia 112: 551-556.
Fyles, T. W. 1917. The naturalist in the city. Annual report of the Entomological Society of Ontario 47: 28-31.
Gauld, I. D. and Mound, L. A. 1982. Homoplasy and delineation of holophyletic genera in some insect groups. Systematic Entomology 7: 73-86.
Gaut, I. P. C. 1969. Identity of the fungal symbiont of Sirex noctilio. Australian Journal of Biological Sciences 22: 905–914.
Gaut, I. P. C. 1970. Studies of siricids and their fungal Symbionts. Ph.D thesis. Waite Agricultural Research Institute, University of Adelaide, Australia. 166 pp.
Geoffroy, E. L. 1785. Entomologia Parisiensis; sive catalogus insectorum quae in agro Parisiensi reperiuntur ; secundum methodum Geoffraeanam in sectiones, genera et species distributus ; cui addita sunt nomina triviala et fere trecentae novae species. Fourcroy, Paris. Pars 2 : VIII+544 pp.
Ghigi, A. 1909 (1908). Sopra una nuova specie di Siricide delle Azores. Bolletino della Società Entomologica Italiana 40(3-4): 163-170.
Gilbert, J. M. and Miller, L. W. 1952. An outbreak of Sirex noctilio (F.) in Tasmania. Australian Forestry 16: 63-69.
Gmelin, J. F. 1790: Caroli a Linné Systema Naturae. 13. ed. - Lipsiae 1(5): 2225-3020
Goulet, H. 1992. The genera and subgenera of the sawflies of Canada and Alaska. Hymenoptera: Symphyta. The Insects and Arachnids of Canada. Part 20. 235 pp.
Gourlay, E. S. 1951. Notes on insects associated with Pinus radiata in New Zealand. Bulletin of Entomological Research 42: 21-22.
Gussakovskij, V. V. 1935. Insectes Hyménoptères. Tome II. Vol. 1. Chalastogastra. Part 1. Faune d l'URSS (N.S.). No. 1. 453 pp.
Hajibabaei, M., Janzen, D. H., Burns, J. M., Hallwachs, W. and Hebert, P. D. N. 2006. DNA barcodes distinguish species of tropical Lepidoptera. Proceedings of the National Academy of Science 103: 968–971.
Harrington, W. H. 1882a. Notes on the occurrence of some species of Uroceridae. The Canadian Entomologist 14: 224-228.
Harrington, W. H. 1882b. A new foe to the maple. Entomological Society of Ontario. Report 14: 40-42.
Harrington, W. H. 1887. Insects infesting maple trees. Entomological Society of Ontario. Report 17: 22–23.
Harrington, W. H. 1893. Canadian Hymenoptera – No. 3. The Canadian Entomologist 25(3): 57-64.
Harris, M. 1782. Exposition of British insects. White and Robson, London. VIII +166 pp. + 44 pls. [plate 28 and p. 96 were published in 1779 – see Evenhuis 1997.]
Harris, T. W. 1827. Doct'r Hunt's insect. New England Farmer 5(27): 211.
Harris, T. W. 1833: VIII. Insects. In: Part IV. Catalogues of animals and plants. - In: Hitchcock, E. 1833: Report on the geology, mineralogy, botany, and zoology of Massachusetts. Made and published by order of the government of that state: in four parts: part I. Economical geology. part II. Topographical geology. part III. Scientific geology. part IV. Catalogues of animals and plants. With a descriptive list of the specimens of rocks and minerals collected for the government. Illustrated by numerous wood cuts and an atlas of plates. - Amherst, Press of J. S. and C. Adams : XII+1-700 : 566-595.
Harris, T. W. 1841. A Report on the Insects of Massachusetts, injurious to vegetation, published agreeably to an order of the Legislature, by the Commissioners on the Zoological Survey of the State. Cambridge, Massachusetts. viii + 459 pp.
Hartig, T. 1837. Die Aderflügler Deutschlands mit besonderer Berücksichtigung ihres Larvenzustandes und ihres Wirkens in Wäldern und Gärten für Entomologen, Wald- und Gartenbesitzer. Die Familien der Blattwespen und Holzwespen nebst einer allgemeinen Einleitung zur Naturgeschichte der Hymenopteren. Berlin, i-xiv + 416 pp. + VIII plates
Haugen D. A., Bedding, R. A., Underdown, M. G., and Neumann, F. G. 1990. National strategy for control of Sirex noctilio in Australia. Australian Forest Grower 13(2): Special liftout section No. 13. 8pp.
Haugen, D. and Hoebeke, E. R. 2005. Sirex woodwasp – Sirex noctilio F. (Hymenoptera: Siricidae). NA–PR–07–05, United States Forest Service, Northeastern Area, State and Private Forestry. 2 pp.
Haugen D. A. and Underdown, M. G. 1990. Sirex noctilio control program in response to the 1987 Green Triangle outbreak. Australian Forestry 53: 33–40.
Hebert, P.D.N., Cywinska, A., Ball, S. L. and deWaard, J. R. 2003. Biological identifications through DNA barcodes. Proceedings of the Royal Society London B 270: 313–321.
Hebert, P. D. N., Penton, E. H., Burns, J. M., Janzen, D. H. and Hallwachs, W. 2004. Ten species in one: DNA barcoding reveals cryptic species in the neotropical skipper butterfly Astraptes fulgerator. Proceedings of the National Academy of Science 101: 14812–14817.
Hebert, P. D. N., Stoeckle, M. Y., Zemlak, T. S. and Francis, C. M. 2004A. Identification of birds through DNA barcodes. PLoS Biol 2(10): e312
Hedicke, H. 1938. Siricidae. Pp. 1-32. In Hedicke, H., (ed.). Hymenopterorum Catalogus, pars 6.
Hennig, W. 1966. Phylogenetics. University of Illinois Press. Urbana. 263 pp.
Herrick, G. W. 1935. Insect enemies of shade-trees. Comstock Publishing Company, Ithaca, New York. 9 + 417 pp.
Heyden von, L. 1868. Ueber das seither unbekannt Männchen von Xyloterus fuscicornis F. (Hymenopt.). Berliner Entomologische Zeitschrift 12(1-2): 227-230.
Hoebeke, E. R. 1980. Catalogue of the Hymenoptera types in the Cornell University collection. Part I: Sympyta and Aprocrita (Parasitica). Cornell University Agricultural Experimental Station, Ithaca, N. Y., No. 9. 36 pp.
Hoebeke, E. R., Haugen, D. A. and Haack, R. A. 2005. Sirex noctilio: Discovery of a Palearctic siricid woodwasp in New York. Newsletter of the Michigan Entomological Society 50: 24-25.
Hogg, I. D. and Hebert, P. D. N. 2004. Biological identification of springtails (Collembolan: Hexapoda) from the Canadian arctic, using mitochondrial DNA barcodes. Canadian Journal of Zoology 82: 1–6.
Holway, R. T. 1935. Preliminary note on the structure of the pretarsus and its possible phylogenetic significance. Psyche 42: 1-24.
Horn, Walther (H. R.), Kahle, I., Friese, G. & Gaedike, R. 1990. Collectiones entomologicae. Ein Kompendium über den Verbleib entomologischer Sammlungen der Welt bis 1960. Akademie der Landwirtschaftswissenschaften der Deutschen Demokratischen Republik, Berlin, 2 vols., 1-220 and 221-573, 38 pls, 125 photos.
Huber, J. R. and Sharkey, M. J. 1993. Chapter 3. Structure, pp. 13-59, in Goulet, H. and Huber, J. T. (eds.). Hymenoptera of the World: An Identification Guide to Families. Research Branch, Agriculture Canada, Publication 1894/E. 668 pp.
ICZN. 2000. International code of zoological nomenclature. 4th edition. The International Trust for Zoological Nomenclature, London, xxix + 309 pp.
Iede, E. T., Schaitza, E., Penteado, S., Reardon, R. C. and Murphy, S. T. eds. 1998. Proceedings of a Conference Training in the Control of Sirex noctilio by the use of Natural Enemies. Colombo, Brazil, November 4–9, 1996. Forest Health Technology Enterprise Team, Technology Transfer, Biological Control, Morgantown, WV, 8–13. 96 pp.
Jennings, J., Austin, J. T. and Schiff, N. M. 2009. The Australian endemic woodwasp genus Austrocyrtus Riek (Hymenoptera: Xiphydriidae). Australian Jourmal of Entomology 48: 29–35.
Johnson, C. W. 1928. The New England Siricidae or horntails. Bulletin of the Boston Society of Natural History 49: 3-7.
Johnson, C. W. 1930. On the variation and abundance of Sirex nitidus Harris. Psyche 38: 281-282.
Jurine, L. 1807. Nouvelle Méthode de classer les Hyménoptères et les Diptères. Genève et Paris, Vol. 4, 319 pp + 7 pl.
Kirby, W. F. 1882. List of Hymenoptera with descriptions and figures of the typical specimens in the British Museum. 1. Tenthredinidae and Siricidae. London, by order of the Trustees, Vol. 1. 450 pp.
Kirk, A. A. 1974. Siricid woodwasps and their associated parasitoids in the southeastern United States (Hymenoptera: Siricidae). Journal of the Georgia Entomological Society 9: 139-144.
Kirk, A. A. 1975. Siricid woodwasps and their associated parasitoids in the southwestern United States. Pan-Pacific Entomologist 51: 57-61.
Kjellander, E. 1945. Sirex juvencus L. and noctilio Fabr., two good species. Fysiografiska Sällskapet i Lund, Förhandlingar 15: 121-126.
Klasmer, P. (2002). Urocerus: Avispa taladradora de los pinus. Secretaria de Agricultura, Ganaderia, Pesca y Altimentacion, Instituto Nacional de Tecnologia, Proyecto Forestal de Desarrollo Instituto Nacional de Tecnologia (Argentina), Hoya Divulgativa Tecnica 16, 2 pp. http://www.inta.gov.ar/bariloche/info/documentos/forestal/silvicul/hdt16.pdf (accessed December 12, 2010)
Konow, F. W. 1896. Verschiedenes aus der Hymenoptern-Gruppe der Tenthrediniden. Wiener Entomologische Zeitung 15: 41-59.
Konow, F. W. 1898. Systematische und kritische Bearbeitung der Siriciden-Tribus Siricini. Wiener Entomologische Zeitung 17: 73-91.
Konow, F. W. 1905a. Fam. Siricidae. In: Wytsman, P., (ed.), Genera Insectorum, Fasc. 28. 14 pp.
Konow, F. W. 1905b. Systematische Zusammenstellung der bisher bekannt gewordenen Chalastrogastra (Hym.). Zeitschrift für Systematische Hymenopterologie und Dipterologie 6: 97-128.
Koutroumpa F. A., Lieutier, F. and Roux-Marabito, G. 2009. Incorporation of mitochondrial fragments in the nuclear genome (Numts) of the longhorned beetle Monochamus galloprovincialis (Coleoptera, Cerambycidae). Journal of Zoological Systematics and Evolutionary Research 47: 141–148.
Kukor, J. J. and Martin, M. M. 1983. Acquisition of digestive enzymes by siricid woodwasps from their fungal symbiont. Science 220: 1161–1163.
Latreille, P. A. 1810. Considérations générales sur l'ordre naturel des animaux composant les classes des Crustacés, des Arachnides et des Insectes; avec un tableau méthodique de leurs genres, disposés en familles. Paris, F. Schoell, 444 pp.
Laurent, P. 1931. Notes on Tremex columba Linn. (Hymen.: Siricidae). Entomological News 42: 67.
Linnaeus, C. 1758. Systema Naturae, per regna tria naturae secundum classes, ordines, genera, species cum characteribus, differentiis, synonymis, locis. 10th edition. Laurentius Salvius, Holmiae, Vol. 1, 824 pp.
Linnaeus, C. 1760 [1761]. Fauna Svecica sistens animalia Sveciae regni: Mammalia, Aves, Amphibia, Pisces, Insecta, Vermes. Ed. 2. L. Salvius, Holmiae. 578 pp.
Linnaeus, C. 1763. Centuria insectorum rariorum. Uppsala. 32 pp.
Linnen, C. R. and Farrell, B. D. 2007. Mitonuclear Discordance is caused by rampant mitochondrial introgression in Neodiprion (Hymenoptera: Diprionidae) sawflies. Evolution 61: 1417–1438.
Linnen, C. R. and Farrell, B. D. 2008. Phylogenetic analysis of nuclear and mitochondrial genes reveals evolutionary relationships and mitochondrial introgression in the sertifer species group of the genus Neodiprion (Hymenoptera: Diprionidae). Molecular Phylogenetics and Evolution 48: 240–257.
Lintner, J. A. 1897. Twelfth report on the injurious and other insects of the State of New York for the year 1896 (reprinted from the fiftieth report of the New York State Museum). University of the State of New York, Albany. 399 pp.
Lintner, J. A. 1898. New York State Museum. 13th report of state entomologist (reprinted from 51st annual report of the New York State Museum [1897]). University of the state of New York, Albany. 2 + 331-240.
Liu, Z. and Nordlander, G. 1992. Ibaliid parasitoids of siricid woodwasps in North America: Two new Ibalia species and a key to species (Hymenoptera: Cynipoidea). Proceedings of the Entomological Society of Washington 94: 500-507.
Liu, Z. and Nordlander, G. 1994. Review of the family Ibaliidae (Hymenoptera: Cynipoidea) with keys to genera and species of the world. Entomologica Scandinavica 25: 377-392.
Lopez, J. V., Yuhki, N, Masuda, R., Modi, W. and Obrien, S. J. 1994. Numt, a recent transfer and tandem amplification of Mitochondrial DNA to the nuclear genome of the domestic cat. Journal of Molecular Evolution 39: 174–190.
Maa, T. 1949. A synopsis of Asiatic Siricoidea with notes on certain exotic and fossil forms (Hymenoptera Symphyta). Musée Heude, Notes d'Entomologie Chinoise 13: 11-189.
Maa, T. 1956. Notes on the Genus Eriotremex Benson (Hymenoptera: Siricidae). Proceedings of the Hawaiian Entomological Society 16(1): 91-94.
MacGillivray, A. D. 1893. Washington Tenthredinidae and Uroceridae. The Canadian Entomologist 25: 237-244.
Madden J. L. 1968. Physiological aspects of host tree favourability for the woodwasp, Sirex noctilio F. Proceedings of the Ecological Society of Australia 3: 147–149.
Madden, J.L. 1971. Some treatments which render Monterey pine (Pinus radiata) attractive to the woodwasp Sirex noctilio F. Bulletin of Entomological Research 60: 467–472.
Madden, J. L. 1981. Egg and larval development in the woodwasp Sirex noctilio F. Australian Journal of Forestry 22: 341–351.
Madden, J. L. 1982. Avian predation of the woodwasp, Sirex noctilio F., and its parasitoid complex in Tasmania. Australian Wildlife Research 9: 135–144.
Madden, J. L. and Irvine, C. J. 1971. The use of lure trees for the detection of Sirex noctilio in the field. Australian Forestry 35: 164–166.
Malaise, R. and Benson, R. B. 1934. The Linnean types of sawflies (Hymenoptera Symphyta). Arkiv for Zoolögi. Band 26, No. 20. 1-14.
Marshall, S. A. 2006. Insects their natural history and diversity with a photographic guide to insects of eastern North America. Firefly Books Ltd., Buffalo, New York and Richmond Hill, Ontario. 718 pp.
Mason, W. R. M. 1993. Key to superfamilies of Hymenoptera. Pp. 65-100, in Goulet, H. and Huber, J. T. (eds.). Hymenoptera of the World: An Identification Guide to Families. Research Branch, Agriculture Canada, Publication 1894/E. 668 pp.
Matsumura, S. 1912. Thousand insects of Japan. Supplement IV. Keiseisha, Tokyo. 247 pp., Tab. XLII-LV.
Maxwell, D.E. 1955. The comparative antomy of sawflies (Hymenoptera: Symphyta). The Canadian Entomologist 50 (Supplement 1): 132 pp.
McIntosh, R. L., Katinic, P.J., Allison, J.D., Borden, J. H. and Downey, D.L. 2001. Comparative efficacy of five types of trap for woodborers in the Cerambycidae, Buprestidae and Siricidae. Agricultural and Forest Entomology 3: 113–120.
Middlekauff, W. W. 1948. A new species of Sirex from California (Hymenoptera: Siricidae). Pan-Pacific Entomologist 24: 189-190.
Middlekauff, W. W. 1960. The siricid wood wasps of California (Hymenoptera: Siricidae). Bulletin of the California Insect Survey 6(4): 59-77.
Middlekauff, W. W. 1962. Notes and description of the previously unknown male of Sirex longicauda. Pan-Pacific Entomologist 38: 31-32.
Miller D. and Clark, A. F. 1935. Sirex noctilio (Hym.) and its parasites in New Zealand. Bulletin of Entomological Research 26: 149-154.
Minko, G. 1981. Chemicals for non-commercial thinning of Pinus radiata by basal stem injection. Australian Weeds 1: 5–6.
Mocsáry, A. 1881. Hymenoptera nova e variis orbis terrarum partibus. Természetrajzi Füzetek, Budapest 5(1): 29-37
Mocsáry, A. 1891. Tenthredinidae et Siricidae novae. Természetrajzi Füzetek 14: 155-159.
Morgan, F. D. 1968. Bionomics of the Siricidae. Annual Review of Entomology 13: 239-256.
Morgan, F. D. and Stewart, N. C. 1972. Developing and testing a lure-trap for the woodwasp Sirex noctilio F. Australian Forestry 36: 38–46.
Morris, E. V. 1967. Distribution and hosts of some horntails (Siricidae) in British Columbia. Journal of the Entomological Society of British Columbia 64: 60-63.
Newmann F. G., Harris, J. A., Kassaby, F. Y. and Minko, G. 1982. An improved technique for early detection and control of the Sirex wood wasp in radiate pine plantations. Australian Forestry 45: 117–124.
Nielsen, C., Williams, D. W. and Hajek, A. E. 2009. Putative source of the invasive Sirex noctilio fungal symbiont, Amylostereum areolatum, in the eastern United States and its association with native siricid wasps. British Mycological Journal 113: 1242–1253.
Norton, E. 1864. Notes on Tenthredinidae, with descriptions of new species, in the collection of the Entomological Society. Proceedings of the Entomological Society of Philadelphia 3: 5-16.
Norton, E. 1869. Catalogue of the described Tenthredinidae and Uroceridae of North America. Transactions of the American Entomological Society 2: 211–242, 321–368.
Okutani, T. 1965. A list of horntails found on imported logs. Akitu 12: 30-32.
Packard, A. S. 1881. Insects injurious to shade and forest trees. Bulletin of the United States Entomological commission 7: 105-106
Packard, A. S. 1890. Insects injurious to forest and shade trees. Report of the United States Entomological Commission 5: 7 + 957 pp.
Palma C. M. A., Valenzuela, E., Parra, P., Gutierrez, M. and Silva, L. T. 2005. Cerrena unicolor (Bull.) Murr (Basidiomycota) aislado de micangio de Tremex fuscicornis Fabr. (Hymenoptero Siricidae) asociado a decaimiento y pudricion del Alamo (Populus sp.) en Chile. Boletin Micologico 20: 57-61.
Pamilo, P., Viljakainen, L. and Vihaiven, A. 2007. Exceptionally high density of NUMT’s in the honey bee genome. Molecular Biology and Evolution 24: 1340–1346.
Parkin, E. A. 1941. Symbiosis in larval Siricidae (Hymenoptera). Nature 147: 1941.
Parkin, E. A. 1942. Symbiosis and siricid woodwasps. Annals of Applied Biology 29: 268–274.
Parra S. P. 2007. Antecedentes biologicos de Tremex fuscicornis Fabr. Programa Monitoreo Fitosanitario Forestal, Instituto Forestal, Chile, 7 pp.
Pasteels, J. 1951. Sur quelques Tenthredinoidea africains. Bulletin et Annales de la Société Entomologique de Belgique 887: 195-205.
Pažoutová, S. and Šrǔtka, P. 2007. Symbiotic relationship between Cerrena unicolor and the horntail Tremex fuscicornis recorded in the Czech Republic. Czech Mycologia 59: 83-90.
Peck, O. 1937. The males of Urocerus albicornis F. and U. flavicornis F. (Hymenoptera: Siricidae). The Canadian Entomologist 59: 275-276.
Provancher, L. 1868. Description d'un nouvel Hyménoptère, genre Urocérus Goeffroy. Le Naturaliste Canadien 1 : 17-20.
Provancher, L. 1979. Faune canadienne. Les insects-hyménoptères. Le Naturaliste Canadien 11: 205-233.
Provancher, L. 1883. Petite faune entomologique du Canada et particulièrement de la province de Québec. Vol 2 comprenant les Orthoptères, les Neuroptères et les Hyménoptères. C. Darveau, Québec. 830 pp.
Rasnitsyn, A. P. 1968. Novje MesozojskiePili’schiki (Hymenoptera: Symphyta) [New Mesozoic sawflies (Hymenoptera: Symphyta)]. (In Russian). In Rodendorf, B. B., Jurskie Nasekomye Karatau. Nauka, Moskva, pp. 190-236.
Rawlings, G. B. 1953. Rearing of Sirex noctilio and its parasites Ibalia leucospoides. New Zealand Forestry Research. Notes 1: 20-34.
Rawlings, G. B. 1955. Insect epidemics in Pinus radiata forests in New Zealand. New Zealand Journal of Forestry 7: 53-55.
Reeks, W. A. and Smith, C. C. 1945. A list of some forest insects of Newfoundland. Acadian Naturalist 2(5): 1-17.
Ries, D. T. 1946. Urocerus gigas Fabricius in Brazil (Hym.: Siricidae). Entomological News 57: 218.
Ries, D. T. 1951. Siricoidea. Pp. 82-86, in Muesebeck C. F. W., K. V. Krombein, and H. K. Townes (eds.). Hymenoptera of America North of Mexico. Synoptic Catalog. United States Department of Agriculture, Monograph No. 2. 1420 pp.
Riley, C. V. 1870. Popular and practical entomology and botany. The American Entomologist and Botanist. Vol 2(4): 384 pp.
Riley, C. V. 1888. The habits of Thallessa and Tremex. Insect Life 1: 168-179.
Roe, A. D., Stein, J. D., Gilette, N. E. and Sperling, F. A. H. 2006. Identification of Dioryctria (Lepidoptera : Pyralidae) in a seed orchard at Chico, California. Annals of the Entomological Society of America 99: 433–448.
Rohwer, S. A. 1911. Technical papers on miscellaneous forest insects. II. The genotypes of the sawflies or woodwasps, or the superfamily Tenthredinoidea. Technical series, United States Department of Agriculture, Bureau of Entomology, Washington, DC 20: 69-109.
Rohwer, S. A. 1928. Suborder Chalastogastra. Pp. 871-895, in Leonard, M. D. (Ed.). A list of the insects of New York with a list of the spiders and certain other allied groups. Cornell University Agricultural experiment Station. Memoirs 101: 1121 pp.
Ross, H. H. 1937. A generic classification of the Nearctic sawflies (Hymenoptera: Symphyta). Illinois Biological Monograph 15, 173 pp.
Rubinoff, D., Cameron, S. and Will, K. 2006. A genomic perspective on the shortcomings of Mitochondrial DNA for “Barcoding” Identification. Journal of Heredity 97: 581–594.
Saini, M.S. 2009. Indian Sawflies. Biodiversity, Keys, Catalogue & Illustrations. (Vol. VI) Families Argidae, Cimbicidae, Diprionidae, Pamphiliidae, Siricidae, Xiphydriidae and Orussidae. Bishen Singh Mahendra Pal Singh, Dehra Dun, India. 168 pp.
Saini, M. S. and Singh, D. 1987. A new genus and a new species of Siricinae (Insecta, Hymenoptera, Siricidae) from India with a revised key to its world genera. Zoologica Scripta 16: 177-180.
Saitou, N. and Nei, M. 1987. The neighbor-joining method: a new method for reconstructing phylogenetic trees. Molecular Evolution Biology and Evolution 4: 406–425.
Saunders, W. 1883. Insects affecting forest trees. Fruit growers Association of Ontario for the year 1882. Pp. 268-282.
Saunt, J. W. 1924. Sirex areolatus Cresson in Britain. Entomologist's Monthly Magazine 60: 80.
Say, T. 1823. A description of some new species of Hymenopterous insects. Western Quarterly Reporter 2: 71-82.
Say, T. 1825. American entomology or description of the insects of North America. Vol. II. W. Brown, Philadelphia. 121 pp. + pls 19-36.
Schiff, N. M., Valley, S. A., LaBonte, J. R. and Smith, D. R. 2006. Guide to the siricid woodwasps of North America. United States Department of Agriculture Forest Service, Forest Health Technology Enterprise Team, Morgantown, West Virginia, FHTET-2006-15. 102 pp. http://www.aphis.usda.gov/plant_health/plant_pest_info/sirex/downloads/guidesiricidwoodwasps.pdf. (accessed January 10, 2011)
Schulmeister, S. 2003. Morphology and evolution of the tarsal plantulae in Hymenoptera (Insecta), focusing on the basal lineages. The Norwegian Academy of Science and Letters. Zoologica Scripta 32: 153-172.
Semenov-Tian-Shanskij, A. 1921 (1917). Praecursoriae siricidarum novorum diagnoses (Hymenoptera). Russkoe Entomologicheskoe Obozrenie 17: 81-95.
Shuckard, W. E. 1837. Description of a new species of Sirex discovered to attack and destroy the Spruce Fir (Pinus nigra). Magazine of Natural History (n.s.) 1: 630-632.
Skevington, J. H. (2008). Hilltopping. In: Encyclopedia of Entomology. Second Edition. J. L. Capinera (Ed), Springer. 4: 1799-1807.
Slippers, B., Coutinho, T. A., Wingfield, B. D. and Wingfield, M. J. 2003. A review of the genus Amylostereum and its association with woodwasps. South African Journal of Science 99: 70–74.
Slippers, B., de Groot, P. and Wingfield, M. J. 2011. The Sirex woodwasp and its fungal symbiont: research and management of a worldwide invasive pest. Springer, Dordrecht, The Netherlands. xv + 301 pp.
Slippers, B., and Haugen, D. A. 2009. Sirex literature. Forestry and Agricultural Biotechnology Institute. http://www.fabinet.up.ac.za/sirex/sirexref (accessed on January 10, 2011)
Slosson, A. T. 1895. Additional list of insects taken in alpine region of Mt. Washington. Entomological News 6: 317.
Smith, D. R. 1969. Symphyta of the West Indies, including those collected during the Bredin-Archbold-Smithsonian biological survey of Dominica (Symphyta). Proceeding of the Entomological Society of Washington 71: 540-543.
Smith, D. R. 1975a. The sawfly types of Abbé Léon Provancher (Hymenoptera: Symphyta). Le Naturaliste Canadien 102: 293-304.
Smith, D. R. 1975b. Eriotremex formosanus (Matsumura), an Asian horntail in North America (Hymenoptera: Siricidae). United States Department of Agriculture, Cooperative Economic Insect Report 25(44): 851-854.
Smith, D. R. 1976. The Xiphydriid woodwasps of North America (Hymenoptera: Xiphydriidae). Transactions of the American Entomological Society 102: 101–131.
Smith, D. R. 1978. Suborder Symphyta (Xyelidae, Parachexyelidae, Parapamphiliidae, Xyelydidae, Karatavitidae, Gigasiricidae, Sepulcidae, Pseudosiricidae, Anaxyelidae, Siricidae, Xiphydriidae, Paroryssidae, Xyelotomidae, Blasticotomidae, Pergidae). In van der Vecht, J. and R. D. Shenefelt, eds. Hymenopterorum Catalogus, pars 14. W. Junk B. V., Publishers, The Hague. 193 pp.
Smith, D. R. 1979. Symphyta. Pp. 3-132, in Krombein, K. V., P. D. Hurd, Jr., D. R. Smith, and B. D. Burks, (eds), Catalog of Hymenoptera in America North of Mexico, Vol. 1. Smithsonian Institution Press, Washington, D.C. 1198 pp.
Smith, D. R. 1981. New records for Eriotremex (Hymenoptera: Siricidae) from southeast Asia and New Guinea. Proceedings of the Entomological Society of Washington 83: 389.
Smith, D. R. 1986. Review of the sawfly genus Lagium (Hymenoptera: Tenthredinidae). Proceedings of the Entomological Society of Washington 88: 179–184.
Smith, D. R. 1987. Urocerus sah (Mocsáry) (Hymenoptera: Siricidae) new to North America and key to North American species of Urocerus. Proceedings of the Entomological Society of Washington 89: 834-835.
Smith, D. R. 1988. A synopsis of the sawflies (Hymenoptera: Symphyta) of America south of the United States: Introduction, Xyelidae, Pamphiliidae, Cimbicidae, Diprionidae, Xiphydriidae, Siricidae, Orussidae, Cephidae. Systematic Entomology 13: 205-261.
Smith, D. R. 1996. Discovery and spread of the Asian horntail, Eriotremex formosanus (Matsumura) (Hymenoptera: Siricidae), in the United States. Journal of Entomological Science 31: 166-171.
Smith, D. R. 1997. Collections of Stephanidae (Hymenoptera) in the mid–Atlantic states including an eastern record for Schlettererius cinctipes (Cresson). Proceedings of the Entomological Society of Washington 99: 377–378.
Smith, D. R. 2010. The woodwasp genus Eriotremex (Hymenoptera: Siricidae), a review and new species from Malaysia. Proceedings of the Entomological Society of Washington 112(3): 423–438.
Smith, D. R and Schiff, N. M. 1998. The genera Macroxyela Kirby and Megaxyela Ashmead (Hymenoptera: Xyelidae) in North America. Proceedings of the Entomological Society of Washington 100: 636–657.
Smith, D. R. and Schiff, N. M. 2002. A review of the siricid woodwasps and their ibaliid parasitoids (Hymenoptera: Siricidae, Ibaliidae) in the eastern United States, with emphasis on the mid-Atlantic region. Proceedings of the Entomological Society of Washington 104: 174-194.
Smith, M. A., Woodley, N. E., Janzen, D. H., Hallwachs, W. and Hebert, P. D. N. 2006. DNA barcodes reveal cryptic host-specificity within the presumed polyphagous members of a genus of parasitoid flies (Diptera: Tachinidae). Proceedings of the National Academy of Science 103: 3657–3662.
Smith, R. C. 1943. A list and brief description of the most important or interesting species of insects in Kansas by orders and families. Pp. 117-440, in Smith, R. C., E. G. Kelly, G. A, Dean, H. R. Bryson and R. L. Parker. Common insects in Kansas. Reprot of the Kansas State Board of Agriculture. W. C. Austin State Printer, Topeka. 440 pp.
Solomon, J. D. 1995. Guide to insect borers in North American broadleaf trees and shrubs. Agriculture Handbook 706. Washington D.C. United States Department of Agriculture, Forest Service. 735 pp.
Song, H., Buhay, J. E., Whiting, M. F. and Crandall, K. A. 2008. Many species in one: DNA barcoding overestimates the number of species when nuclear mitochondrial pseudogenes are coamplified. Proceedings of the National Academy of Science 105: 13486–13491.
Spradery, J. P. 1969. The biology of Pseudorhyssa sternata Merrill (Hym, Ichneumonidae), a cleptoparasite of siricid woodwasps. Bulletin of Entomological Research 59: 290-297.
Spradbery, J. P. 1970. Host finding by Rhyssa persuasoria (L.) and ichneumonid parasite of siricid woodwasps. Animal behaviour 18(1): 103-114.
Spradbery, J. P. 1973. A comparative study of the phytotoxic effects of siricid woodwasps on conifers. Annals of Applied Biology 75: 309–320.
Spradbery, J. P. 1977. The oviposition biology of siricid woodwasps in Europe. Ecological Entomology 2: 225–230.
Spradberry, P. J. 1990. Predation of larval siricid woodwasps (Hymenoptera: Siricidae) by woodpeckers in Europe. The Entomologist 109: 67–71.
Spradbery, J. P. and Kirk, A. A. 1978. Aspects of the ecology of siricid woodwasps (Hymenoptera: Siricidae) in Europe, North Africa and Turkey with special reference to the biological control of Sirex noctilio F. in Australia. Bulletin of Entomological Research 68: 341–359.
Stange, L. A. 1996. The horntails of Florida (Hymenoptera: Siricidae). Florida Department of Agriculture and Consumer Services, Division of Plant Industry, Entomology Circular No. 376.
Stephens, J. F. 1929. The nomenclature of British insects. Baldwin and Cradock, London. 68 pp.
Stephens, J. F. 1835. Illustrations of British entomology; or, a synopsis of indigenous insects: containing their generic and specific distinctions; with an account of their metamorphosis, times of appearance, localities, food, and economy, as far as practicable. Mandibulata. Vol VII. Baldwin and Cradock, London. 2+310 pp.
Stillwell, M. A. 1960. Decay associated with woodwasps in balsam fir weakened by insect attacks. Forest Science 6(3): 225-229.
Stillwell, M. A. 1964. The fungus associated with woodwasps occurring in beech in New Brunswick. The Canadian Journal of Botany 42: 495-496.
Stillwell, M. A. 1965. Hypopleural organs of the woodwasp larva Tremex columba (L.) containing the fungus Daedalea unicolor Bull. ex Fries. The Canadian Entomologist 97: 783-784.
Stillwell, M. A. 1966. Woodwasps (Siricidae) in conifers and the associated fungus, Stereum chailletii in eastern Canada. Forest Science 12: 121-128.
Stillwell, M. A. 1967. The pigeon tremex, Tremex columba (Hymenoptera: Siricidae), in New Brunswick. The Canadian Entomologist 99: 685-689.
Tabata, M. and Abe, Y. 1995. Cerrena unicolor isolated from the mycangia of a horntail, Tremex longicollis, in Kochi prefecture, Japan. Mycoscience 36: 447–450.
Tabata, M. and Abe, Y. 1997. Amylostereum laevigatum associated with the Japanese horntail, Urocerus japonicus. Mycoscience 38: 421–427.
Tabata, M. and Abe, Y. 1999. Amylostereum laevigatum associated with a horntail, Urocerus antennatus. Mycoscience 40: 535–539.
Taeger, A. and Blank, S. M. 2011. ECatSym – Electronic World Catalog of Symphyta (Insecta, Hymenoptera). Program version 3.10(07.12.2011) – Digital Entomological Information, Müncheberg. http://www.sdei.de/ecatsym/index.html (accessed on May 18, 2011)
Taeger, A., Blank, S. M. and Liston, A. D. 2010. World Catalog of Symphyta (Hymenoptera). Zootaxa 2580: 1-1064.
Takeuchi , K. 1938. A systematic study on the suborder Symphyta (Hymenoptera) of the Japanese empire (I). Tenthredo. Acta Entomologica 2(2): 173–229.
Talbot, P. H. B. 1977. The Sirex-Amylostereum-Pinus association. Annual Review of Phytopathology 15: 41–54.
Taylor, J. S. 1962. Sirex noctilio F., a recent introduction in South Africa. Entomologists Record and Journal of Variation 74: 273.
Taylor K. L. 1967a. The introduction, culture, liberation, and recovery of parasites of Sirex noctilio in Tasmania, 1962–67. Australia CSIRO Division of Entomology, Technical Paper No. 8. 19 pp.
Taylor, K. L. 1967b. Parasitism of Sirex noctilio F. by Schlelettererius cinctipes (Cresson) (Hymenoptera: Stepahanidae). Journal of the Australian Entomological Society 6: 13-19.
Taylor, K. L. 1977 (1976). The introduction and establishment of insect parasitoids to control Sirex noctilio in Australia. Entomophaga 21(4): 429-440.
Thomas, C. 1876. Noxious and beneficial insects of the State of Illinois. Report of the State Entomologist 6: 174 + IV + II pp.
Thomas, C. 1881. Uroceridae. Pp. 70-71, in Noxious and beneficial insects of the State of Illinois. Report of the state entomologist 10: 238 + 6 pp.
Thomson C. G. 1871. Hymenoptera Scandinaviae, V. 1. Typis expressit Hage Ohlson, Lundae: 342 pp.
Tonapi, G. T. 1958. A comparative study of spiracular structure and mechanism in some Hymenoptera. Transactions of the Royal Entomological Society of London 110(16): 489-519, Tab i-xii.
Tournier, H. 1890. Descriptions d'espèces nouvelles. L'Entomologiste Genevois 1(11-12): 220-223.
Townes, H. K. 1949. The Nearctic species of the family Stephanidae (Hymnoptera). Proceedings of the United States National Museum 99: 361-370.
Townes, H. K. 1972. A light weight Malaise trap. Entomological News 83: 239–247.
Townes, H. K. and Townes, M. 1960. Ichneumon-flies of America north of Mexico: 2 subfamily Ephialtinae, Xoridinae, Acaenitinae. United States National Museum Bulletin 216. 676 pp.
Townsend G. 1878 Report United States Commissioner of Agriculture. P. 93, Pl. 1, Fig. 15.
Tribe, G. C. 1995. The woodwasp Sirex noctilio Fabricius (Hymenoptera: Siricidae), a pest of Pinus species, now established in South Africa. Journal of the Entomological Society of Southern Africa 3: 215-217.
Tribe, G. C. 1997. Sirex woodwasp expands its range. Plant Protection News, Bulletin of the Plant Protection Institute 49: 9-10.
Vasu, V. and Saini, M. S. 1999. Taxonomic studies on the species of Xeris (Hymenoptera: Symphyta: Siricidae) from India. Polskie Pismo Entomologiczne 68: 273–282.
Viedma de, M. G. and Suarez, F. J. 1961. Un nuevo Xeris de Marruecos (Hym. Siricidae). Graellsia 19: 19–27.
Viitasaari, M. 1984. Sahapistiäiset 3. Siricicoidea, Orussoidea, ja Cephoidea, University of Helsinki, Department of Agricultural and Forest Zoology Reports 6. 66 pp.
Viitasaari, M. 1988. New methods for identification of woodwasps (Siricidae) with notes on Eurosiberian species of Sirex Fabricius. Pp. 9-12, in V. V. Zlobin ed. The connection between entomofauna of the north Europe and Siberia. USSR Academy of Sciences, Zoological Institute, Leningrad, 88p.
Viitasaari, M. and Midtgaard, F. 1989. A contribution to the taxonomy of horntails with notes on the genus Sirex Linnaeus (Hymenoptera, Siricidae). Annales Entomologici Fennici 55: 103-110.
Vilhelmsen, L. 2000. The ovipositor apparatus of basal Hymenoptera (Insecta): Phylogenetic implications and functional morphology. Zoologica Scripta 29: 310-345.
Vilhelmsen, L. 2001. Phylogeny and classification of the extant basal lineages of Hymenoptera (Insecta). Zoological Journal of the Linnean Society 131: 393-442.
Villacide, J. 2010. El exito de invasion de la avispa de los pinos Sirex noctilio en la Patagonia. Agropecuaria, Instituto de Microbiologia y zoologia Agricola, Boletin MIP 20. http://www.inta.gov.ar/imyza/info/bol/mip/10/bol20/mip20.htm (accessed on December 12, 2010)
Walker, F. 1866. Sirex varipes. Pp. 342-343, in Lord, J. K. (ed.). The Naturalist in Vancouver Island and British Columbia. Vol. 2. VII + 375 pp.
Walker, F. 1873. On the geographical distribution of some genera of Canadian insects. The Canadian Entomologist 5:77-78.
Walsh, B. D. and Riley, C. V. 1868. Popular and practical entomology. The American Entomologist. Vol 1(2). R. P. Dtudley and Co., St. Louis Missouri. 252 pp.
Ward, R. D., Zemlak, T. S., Innes, B. H., Last, P. R. and Hebert, P. D. N. 2005. DNA barcoding Australia’s fish species. Philosophical Transactions of the Royal Society B 360: 1847–1859.
Warriner, M. D. 2008. First record of the Asian horntail, Eriotremex formosanus (Hymenoptera: Siricidae) in Arkansas, U.S.A. Entomological News 119: 212-213.
Webb, D. W. 1980. Primary Insect Types in the Illinois Natural History Survey Collection, Exclusive of the Collembola and Thysanoptera. Illinois Natural History Survey Bulletin 32(2): 55-191.
Weber, N. A. 1950. A survey of the insects and related arthropods of Arctic Alaska. Part 1. Transaction of the American Entomological Society 76: 147-206.
Webster, F. M. 1895. The black horned horntail, Urocerus Nigricornis. The Ohio Farmer, August 29, 1895, p. 177.
Westcott, R. L. 1971. New host and distribution records for three western wood-boring Hymenoptera (Syntexidae, Siricidae). Pan-Pacific Entomologist 47: 310.
Westwood, J. O. 1874. Thesaurus entomologicus Oxoniensis; or, illustrations of new, rare, and interesting insects, for the most part contained in the collection presented to the University of Oxford by the Rev. F. W. Hope, M.A., D.C.L., F.R.S., &c. Clarendon Press, Oxford. XXIV+205 pp + 40 plates.
White, S. C. and Salisbury, G. A. 2000. Insect of Kansas. Kansas Department of Agriculture publication 131. 523 pp. [illustrated 3rd edition of Smith et al. 1943]
Whitworth , T. L., Dawson, R. D., Magalon, H. and Baudry, E. 2007. DNA barcoding cannot reliably identify species of the blowfly genus Protocalliphora (Diptera: Calliphoridae). Proceedings of the Royal Society B 274: 1731–1739.
Wickman, B. E. 1964a. Observations on the siricid parasite, Ibalia ensiger. Pan-Pacific Entomologist 40: 19–20.
Wickman, B. E. 1964b. A comparison of radiographic and dissection methods for measuring siricid populations in wood. The Canadian Entomologist 96: 508-510.
Wong, H. R. 1963. The external morphology of the adults and ultimate larval instar of the larch sawfly, Pristiphora erichsonii (Htg.) (Hymenoptera: Tenthredinidae). The Canadian Entomologist 95: 897-921.
Yuasa, H. 1922. A classification of the larvae of the Tenthredinoidea. Illinois biological monographs 7(4): 1-172.
Zondag R. 1962. A nematode disease of Sirex noctilio. Interim Research Release. New Zealand Forest Service, Rotorua, New Zealand. 6 pp.
Zylstra, K. E., Dodds, K. J., Francese, J. A. and Mastro, V. 2010. Sirex noctilio in North America: the effect of stem injection timing on the attractiveness and suitability of trap trees. Agricultural and Forest Entomology 12: 243–250.
Zylstra, K. E. and Mastro, V. C. 2010. The History of Sirex noctilio & the role of USDA APHIS in the northeastern United States. Instituto Nacional de Technologia Agropecuaria, Instituto de Microbiologia y zoologia Agricola, Boletin MIP 20. http://www.inta.gov.ar/imyza/info/bol/mip/10/bol20/mip20.htm (accessed on December 12, 2010)
Appendices
Appendix 1: Statistical Data
Table 1 - Table 2 - Table 3 - Table 4 - Table 5
Table 1. Mean, standard deviation (values for 1, +2 and -2) and range for the proportion of the length of annulus 10 between pits 9 and 10 relative to the diameter of the ovipositor at annulus 10.
| SPECIES (SOURCE) | NUMBER OF SPECIMENS | LENGTH OF ANNULUS 10 RELATIVE TO DIAMETER OF OVIPOSITOR AT ANNULUS 10 | |||||
| MEAN | ST. DEV. | +2 S.D. | -2 S.D. | MIN. | MAX. | ||
| S. nitidus (QC) | 32 | 1.54 | 0.13 | 1.81 | 1.29 | 1.27 | 1.85 |
| S. nitidus (AK) | 30 | 1.65 | 0.12 | 1.87 | 1.39 | 1.43 | 1.76 |
| S. cyaneus (NB) | 40 | 1.57 | 0.12 | 1.82 | 1.33 | 1.30 | 1.77 |
| S. abietinus (BC) | 26 | 2.06 | 0.15 | 2.37 | 1.75 | 1.85 | 2.05 |
Table 2. Mean, standard deviation (values for 1, +2 and -2) and range for the proportion of the length of the basal sheath section relative to the apical sheath section.
Table 3. Mean, standard deviation (values for 1, +2 and -2) and range for the proportion of the length of the sheath relative to the length of the fore wing.
Table 4. Mean, standard deviation (values for 1, +2 and -2) and range for the proportion of the length of apical section of the sheath relative to that of the basal section of the sheath.
Table 5. Mean, standard deviation (values for 1, +2 and -2) and range for the proportion of the length of the metatarsomere 2 relative to the maximum height of the metatarsomere 2.
Appendix 2: Revision to Schiff et al. (2006)
Schiff et al. (2006) published a key to genera and species of the North American Siricidae. Their excellent illustrations should help anyone without a reference collection trying to identify a specimen. However, the revisions below should first be made in the text.
- Page 7
- Figure 3 at centre is an Urocerus and at right a Xeris.
- Page 16
- There are several problems with the key, and it should be avoided. For instance, in key couplet 7 the antennal color for Sirex juvencus juvencus does not work at all (this is S. nitidus or a European specimen of S. juvencus); in couplet 9, Sirex juvencus californicus, should be S. californicus (the pale legged form of the species is not considered in the key and would key to S. cyaneus in couplet 10), and Sirex edwardsii is the dark color form of S. nigricornis.
- Page 17
- Figure 5 (top) is either S. cyaneus or S. nitidus.
- Page 27
- Figure (left). The metatibiae and metafemora are oddly colored (the species cannot be recognized); figure (right), is either a S. nitidus or S. varipes because of spot on the mesotibia and mesotarsomeres 1 and 2.
- Page 28
- The figure is either S. cyaneus or S. nitidus.
- Page 29
- The figure is S. nitidus (based on the visible portion of the ovipositor).
- Page 31
- Sirex edwardsii is the dark color form of S. nigricornis.
- Page 35
- Sirex juvencus californicus should be S. californicus. Females exist in two color forms. The dark form is as in figures on pp. 36 and 37. The pale form is not illustrated but it resembles S. cyaneus or S. nitidus.
- Page 39
- The top figure is S. cyaneus, the left figure may be S. cyaneus, but it is not clear, the right figure is probably S. juvencus based on its antennal color pattern (a pattern that is almost never seen in North America). Sirex juvencus is not found in North America though it has been intercepted many times.
- Pages 40 and 41
- The image is either S. cyaneus or S. nitidus.
- Page 56
- The key to species of Urocerus is good, but the species name of couplet 11 should be interchanged.
- Page 57
- Figure 8. The caption should be reversed. The top image is Urocerus albicornis and the bottom image is U. flavicornis.
- Page 80
- The key is not clear enough as it attempt to segregate only three species of Xeris. Two of the species, X. morrisoni and X. spectrum, are complexes of two and three species respectively. We now know of seven species of Xeris for the region. The figures are clear, however.
- Page 83
- Xeris morrisoni indecisus should be replaced by X. indecisus. This is the pale color form of the species.
- Page 87
- Xeris morrisoni morrisoni should be replaced by Xeris morrisoni.
- Page 91
- The illustration is a male of the black form of Xeris indecisus, not of X. spectrum spectrum.
- Pages 92 and 93
- Xeris spectrum spectrum is either X. melancholicus or X. caudatus.
- Pages 95 and 96
- The illustrations are females of the black form of X. indecisus (X. spectrum townesi is a synonym).
Appendix 3: Disposition of Sequences
FASTA Sequences representing each of the 31 species of this study are deposited in Genbank and at the Center for Bottomland Hardwood Research Web Site.
A set of files in one zip file can be downloaded from the CBHR site at the following URL: http://www.srs.fs.usda.gov/cbhr/products/downloads/2012_nms_SiricidFASTA.zip
The Genbank and Canadian accession numbers are as follows:
| SEQUENCE ID | SPECIES NAME | SPECIMEN CODE | GENBANK ACCESSION NUMBER | CANADIAN COLLECTION SPECIMEN CODE |
| Seq1 | Eriotremex formosana | CBHR4 | JQ619784 | |
| Seq2 | Orussus thoracicus | CBHR35 | JQ619785 | |
| Seq3 | Sirex abietinus | CBHR103 | JQ619786 | |
| Seq4 | Sirex areolatus | CBHR377 | JQ619787 | |
| Seq5 | Sirex behrensii | CBHR669 | JQ619788 | |
| Seq6 | Sirex californicus | CBHR1184 | JQ619789 | |
| Seq7 | Sirex cyaneus | CBHR610 | JQ619790 | |
| Seq8 | Sirex longicauda | CBHR914 | JQ619791 | |
| Seq9 | Sirex near californicus | CNCS1018 | JQ619792 | SIR 018 |
| Seq10 | Sirex near nitidus | CBHR555 | JQ619793 | |
| Seq11 | Sirex nigricornis | CBHR30 | JQ619794 | |
| Seq12 | Sirex nitidus | CBHR615 | JQ619795 | |
| Seq13 | Sirex noctilio | CBHR815 | JQ619796 | |
| Seq14 | Sirex obesus | CNCS1039 | JQ619797 | SIR 039 |
| Seq15 | Sirex varipes | CBHR104 | JQ619798 | |
| Seq16 | Sirex xerophilus | CBHR541 | JQ619799 | |
| Seq17 | Syntexis libocedrii | CBHR9 | JQ619800 | |
| Seq18 | Tremex columba | CBHR5 | JQ619801 | |
| Seq19 | Tremex fuscicornis | CBHR392 | JQ619802 | |
| Seq20 | Urocerus albicornis | CBHR199 | JQ619803 | |
| Seq21 | Urocerus californicus | CBHR2 | JQ619804 | |
| Seq22 | Urocerus cressoni | CBHR169 | JQ619805 | |
| Seq23 | Urocerus flavicornis | CBHR12 | JQ619806 | |
| Seq24 | Urocerus gigas | CBHR842 | JQ619807 | |
| Seq25 | Urocerus taxodii | CBHR31 | JQ619808 | |
| Seq26 | Xeris caudatus | CBHR229 | JQ619809 | |
| Seq27 | Xeris indecisus | CBHR216 | JQ619810 | |
| Seq28 | Xeris melancholicus | CBHR300 | JQ619811 | |
| Seq29 | Xeris morrisoni | CBHR190 | JQ619812 | |
| Seq30 | Xiphydria mellipes | CBHR1055 | JQ619813 | |
| Seq31 | Xoanon matsumurae | SIRCA188 | JQ619814 | SIR 193 |
