1 Insect Systematics Laboratory, School of Environmental Sciences, University of Guelph, Guelph, ON, Canada. [email protected]; [email protected]
2 Instituto Nacional de Pesquisas da Amazônia, Manaus, AM, Brazil / Museu da Amazônia, Manaus, AM, Brazil. [email protected].
3 Canadian National Collection of Insects, Arachnids and Nematodes, Agriculture and Agri-Food Canada, Ottawa, ON, Canada. [email protected]; [email protected].
4Department of Biology, Carleton University, Ottawa, ON, Canada.
5 Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, U.S.A. [email protected].
Representatives of the conspicuous and diverse family Syrphidae are found worldwide, and adults of many species are of considerable economic importance as pollinators. Due to their relatively large size, frequently colourful appearance and conspicuous habits, most syrphid genera are readily identifiable in the field with the help of proper identification tools. We have developed an interactive photographic key that is intuitive to use yet comprehensive, covering all genera of Syrphidae in the Nearctic Region. Every page is fully illustrated, with accompanying text designed to highlight important characters. The key provides the most current classification for the family and adds 15 genera and subgenera not previously recorded or recognized for the region. Several species in the genera Chrysotoxum Meigen 1803, Dasysyrphus Enderlein 1938, Leucozona Schiner 1860, Platycheirus Lepeletier & Serville 1828 and Volucella Geoffroy 1762 are resurrected from synonymy. Two new synonyms are proposed: Ferdinandea dives (Osten Sacken 1877) and F. nigripes (Osten Sacken 1877) are proposed as new synonyms of F. buccata (Loew 1863).
Doros aequalis - Photo by S.A. Marshall
The family Syrphidae (flower flies, hover flies), with almost 6,000 world species and 812 continental Canadian and US species (Tables 1, 2 and 3), is one of the largest fly families. Syrphids are among the most beneficial insects because of their enormous importance as pollinators (Kearns 1992; Kevan 2002; Larson et al. 2001; Ssymank 2008) and because of the major role of predaceous species in natural and biological control of pest aphids and other Sternorrhyncha (Belliure and Michaud 2001; Mengual and Thompson 2011; Rojo et al. 2003; Rotheray 1989). They also play an increasingly recognized role in other ecosystem services such as composting and environmental assessment (Larde 1989; Sommagio 1999; Thompson et al. 2010). Flower flies warrant attention not only because of their impressive diversity and economic importance, but also for their conspicuous habits and frequently eye-catching appearance. Many are astonishingly close mimics of aculeate Hymenoptera and, in general, syrphids are useful models for a variety of ecological research (e.g. Bartsch 2009a, 2009b; Gilbert 2005a, 2005b; Gittings et al. 2006; Marinoni et al. 2004; Montoya et al. 2012; Penney et al. 2012). It is for all of these reasons that there is currently a great deal of interest in Syrphidae amongst photographers, naturalists and professional biologists, all of whom share a common need to correctly and efficiently identify flower flies at least to the generic level. This need was previously met in the Nearctic region with the generic key of Vockeroth and Thompson (1987) (now freely available on line at http://www.esc-sec.ca/aafcmono.html). Vockeroth & Thompson (1987), however, were limited by the constraints of black and white publication in a printed form even though the taxa keyed are characterized by distinct and diverse colour and form.
Those constraints are now lifted, in part thanks to new technology for capturing colour images in the lab and in the field, and in part thanks to new avenues for digital publication. The key presented here takes full advantage of these new opportunities to provide an easier, more accessible method for generic identification of Nearctic Syrphidae.
The work presented here is not simply a repackaging of Vockeroth and Thompson (1987) in a photographic, digital format. Although many couplets do follow previous keys (Stubbs and Falk 1983; Thompson 1972; Vockeroth 1992; Vockeroth and Thompson 1987), there are many new couplets as well as some key components that would not have been possible without the colour/digital format. Furthermore, traditional key characters that have been widely considered difficult to interpret are newly “translated” with detailed, high-resolution photographs that render them easily understood.
Although the current key runs only to the generic level, it is hoped that this paper will be seen as a framework on which to add species reviews and keys in a modular fashion. Such species treatments, although independent papers, could be easily linked from the generic key, rendering the key an effective portal to further levels of information about Syrphidae. The generic pages are already linked to related web pages, such as the Encyclopedia of Life, as appropriate.
There have been some significant changes to our understanding of the Nearctic syrphid fauna since 1987, and these changes are incorporated in this key. Twenty-three of the 121 generic level taxa (Tables 1, 2 and 3) in the current key were not included in Vockeroth and Thompson (1987), and four of the genera included in Vockeroth and Thompson (1987) do not appear in this key since they are now treated as part of other genera or were never confirmed to be present in the Nearctic region (Table 4). We follow the syrphid classification and distribution in Systema Dipterorum (Thompson 2010) with a few exceptions. Because there is as yet no general agreement about the definitions and limits of many syrphid tribes, we refrain from adopting any tribal classification in our work (Tables 1, 2 and 3). These and other taxonomic and classification decisions are outlined in the ‘Results and Discussion’ section below.
Table 4: Genera or subgenera added to or subtracted from the Nearctic syrphid fauna since Vockeroth and Thompson (1987)
Alipumilio Shannon 1927
Chrysosyrphus Sedman 1965
Eosalpingogaster Hull 1949 (previously a subgenus of Salpingogaster Schiner 1868)
Epistrophella Dusek & Laska 1967 (previously a subgenus of Epistrophe Walker 1852)
Eristalinus (Eristalodes) Mik 1897
Eristalinus (Lathyrophthalmus) Mik 1897 (previously considered as the subgenus E. (Eristalinus) Rondani 1845)
Eupeodes (Metasyrphus) Matsumura 1917
Fazia Shannon 1927
Heringia (Neocnemodon) Goffe 1944
Hybobathus Enderlein 1938 (previously treated as Ocyptamus)
Lapposyrphus Dusek & Laska 1967 (previously a subgenus of Eupeodes Osten-Sacken 1877)
Lejops (Eurimyia) Bigot 1883
Megasyrphus Dusek & Laska 1967 (previously a subgenus of Eriozona Schiner 1860)
Meligramma Frey 1946 (previously a subgenus of Melangyna Verall 1901)
Microdon (Omegasyrphus) Giglio-Tos 1891
Microdon (Chymophila) Macquart 1834
Myathropa Rondani 1845
Neoascia (Neoasciella) Stackelberg 1965
Orphnabaccha Hull 1949 (previously treated as Ocyptamus)
Pelecinobaccha Shannon 1927 (previously treated as Ocyptamus)
Pseudoscaeva Vockeroth 1969 (previously treated as Ocyptamus)
Xylota (Ameroxylota) Hippa 1978
Xylota (Sterphoides) Hippa 1978
Synonomies, demotions in rank and removed taxa:
Arctophila Schiner 1860 (now part of Sericomyia (sensu stricto))
Chamaesyrphus Mik 1895 (now Pelecocera (Chamaesyrphus))
E. (Eristalinus) Rondani 1845 (the species E. aeneus (Scopoli 1763) is actually part of the subgenus E. (Lathyrophthalmus) Mik 1897)
Palumbia Rondani 1865 (never proven to be present in the Nearctic region)
Specimens from all Nearctic genera and subgenera of Syrphidae recognized in the current literature (Vockeroth and Thompson 1987; Wirth et al. 1965) were used for illustrating the key. Specimens were obtained from the Canadian National Collection of Insects, Arachnids and Nematodes (CNC, Ottawa, Canada), the University of Guelph Insect Collection (DEBU, Guelph, Canada), and the National Museum of Natural History (USNM, Washington D.C., USA).
The key covers the Nearctic region, including Greenland, Canada, Continental USA and highland regions of Mexico. However, the distribution maps will reflect only North American records north of Mexico, since our nearctic Mexican specimen data is sparse and would be potentially misleading.
To generate the species lists for each genus, we obtained data from Systema Dipterorum (Thompson 2010) and supplemented this with specimen data from the CNC, DEBU and USNM. These collections were exhaustively searched for new material. Dozens of other syrphid collections were also examined but not as thoroughly (examined in parts over years of research or via loans). Several revisions of syrphid genera are under way and although we do not include undescribed species in our lists here, we feel that it is useful to include the most current nomenclature for species that will be split (i.e. resurrected from synonymy) with these anticipated publications.
Distribution maps were generated through Simplemappr (Shorthouse 2010) using the geocoded records from the combined specimen database of the CNC and DEBU collections. For Eosalpingogaster, the geocoded records of Mengual and Thompson (2011) were added to the database. Records from the database are marked as orange points in the maps. Blue points centered in a province/state represent non-geocoded records obtained from Systema Dipterorum (Thompson 2010), but which were not found in the combined specimen database. Maps were formatted using Adobe Illustrator CS4.
Character terminology generally follows Thompson (1999) with the exceptions of a few terms simplified (e.g. ‘hair’ instead of ‘pile’) to make the key accessible to a wide audience as possible. Characters were illustrated using high-magnification photographs of pinned specimens. A Canon EOS 1DS camera mounted on a computer-controlled focusing rail was used to take several photos of each specimen, from the most proximal to the most distal focus point at regular intervals. These raw images were later combined in one high depth of field image using Combine Z software. Wherever possible, the key was supplemented with live fly photos, the majority of which were taken by S. A. Marshall. J. H. Skevington and A. D. Young took other photographs of live specimens for the key, P. Alexander (Polybiomyia townsendi (Snow, 1895)), T. Bentley (Sericomyia flagrans (Osten Sacken, 1875), F. Geller-Grimm (Myathropa florea (Linnaeus, 1758)), R. Hemberger (Scaeva sp.), J. Klymko (Leucozona (Leucozona) americana Curran, 1923), S. McCann (Ornidia obesa (Fabricius, 1775)), G. McDonald (Allograpta micrura (Osten Sacken, 1877), M. florea), H. S. Parker (Pseudoscaeva diversifasciata (Knab, 1914)) and H. Wisch (P. diversifasciata) kindly allowed use of their images, most which were obtained after finding them on BugGuide.net (http://bugguide.net/node/view/15740 ).
The key was developed in Microsoft PowerPoint: Mac 2008 v.12.2.7 (.pptx format) on an iMac 2009 running Mac OS X 10.5.8, and converted to html using the PPTools PPT2HTML software.
There are two types of page formats in the key. One type (multi-option format) has clickable pictures or boxes with text describing diagnostic characters for unique taxa or a group of taxa. The user is then directed to choose from one of the options displayed or to click a button to proceed to another slide with different options. The other type (dichotomous format) has two clickable buttons representing contrasting characters to select from. The picture/box (multi-option format) or button (dichotomous format) either links to a taxon page or to another multi-option or dichotomous page.
Taxa with particularly distinctive characters are displayed early in the key for quick identification. Superficially similar taxa are grouped together and linked to further pages detailing the character states necessary to properly distinguish between them.
The key includes all currently recognized subgenera. When the user reaches a subgeneric identification, the key is linked to a page that shows examples of all subgenera within that genus. This is done to allow for a quick comparison between the subgenera. Although the subgenus that was reached in the key is highlighted in green, all subgenera can be clicked on to explore their respective pages.
Each taxon with two or more species will have references to currently available species keys at the end of each taxon’s species list.
Using the key
As stated above, we follow the syrphid classification and distribution in Systema Dipterorum (Thompson 2010) with a few exceptions. Monoceromyia, Sphiximorpha and Polybiomyia are considered subgenera of Ceriana in the Systema Dipterorum database but they are treated as full genera in the Manual of Central American Diptera (Thompson et al. 2010), which we follow here. We also follow the Manual of Central American Diptera with respect to our treatment of Copestylum and thus do not divide it into subgenera. Evidence for the monophyly of Copestylum subgenera has not been rigorously tested. Ocyptamus is divided into species groups following Miranda (2011) because we anticipate that these groups will be formally recognized (as genera) in the near future. Eosalpingogaster and Salpingogaster are treated as separate genera following Mengual et al. (2008), Mengual and Thompson (2011) and Miranda (2011). Also following Mengual et al. (2008), Epistrophella, Fazia, Lapposyrphus and Meligramma are given full generic status (split from Epistrophe, Allograpta, Eupeodes and Melangyna respectively). The taxa Arctophila and Sericomyia (Conosyrphus) have been synonimized under Sericomyia sensu stricto as proposed by Skevington and Thompson (2012). Chamaesyrphus is proposed as a subgenus of Pelecocera Meigen, 1822 due to the author’s unpublished data that points out to a close affinity between the two taxa.
|Table 1. Genera and species recognized under Eristalinae.|
|Genus||Subgenus||Author, Year||# of NE species|
|Lejops||Lunomyia||Curran & Fluke, 1926||1|
|Ornidia||Lepeltier & Serville, 1828||1|
|Pocota||Lepeltier & Serville, 1828||1|
|Syritta||Lepeltier & Serville, 1828||2|
|Temnostoma||Lepeltier & Serville, 1828||8|
|Total generic taxa||73|
|Table 2. Genera and species recognized under Microdontinae.|
|Genus||Subgenus||Author, Year||# of NE species|
|Total generic taxa||5|
|Table 3. Genera and species recognized under Syrphinae.|
|Genus||Subgenus||Author, Year||# of NE species|
|Epistrophella||Dusek & Laska, 1967||1|
|Lapposyrphus||Dusek & Laska, 1967||2|
|Megasyrphus||Dusek & Laska, 1967||2|
|Platycheirus||Lepeltier & Serville, 1828||73|
|Sphaerophoria||Lepeltier & Serville, 1828||14|
|Total generic taxa||43|
Thanks to Stephen Luk for taking many of the character photographs using the Microptics system; to V. Bura, A. Jewiss-Gaines, B. Kelly, S. Matheson, O. Mitra and V. Nowell for databasing Syrphidae specimens at the CNC and the DEBU collections; to the students at the CANPOLIN Pollinator Identification Course and the University of Guelph for beta testing; to M. Hauser for sharing distributional records of Myathropa florea. Funding to GFGM was provided by Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior (CAPES/MCTI). The Natural Sciences and Engineering Research Council of Canada (NSERC-CANPOLIN) provided for funding much of this work, including support for ADY’s and MML’s graduate studies. This is CANPOLIN publication number 66. NSERC Discovery Grants to SAM and JHS provided additional student support and Agriculture and Agriculture and Agri-Food Canada funding to JHS contributed much of the necessary infrastructure for the work done in Ottawa.
Bartsch, H. 2009a. Diptera: Syrphidae: Syrphinae.ArtDatabanken, Sweden.
Bartsch, H. 2009b. Diptera: Syrphidae: Eristalinae & Microdontinae.ArtDatabanken, Sweden.
Belliure, B. and Michaud, J.P. 2001. Biology and Behaviour of Pseudodorus clavatus (Diptera: Syrphidae), an important predator of citrus aphids. Annals of the Entomological Society of America, 94: 91-96.
Brown, B.V. 1993. A further chemical alternative to critical-point-drying for preparing small (or large) flies. Fly Times, 11: 10.
Cheng, A. 2011. Revision of the New World members of the Volucella bombylans (Diptera, Syrphidae) complex. Honours thesis, Carleton University, Canada.
Coovert, G.A. and Thompson, F.C. 1977. The Sphegina species of eastern North America. Proceedings of the Biological Society of Washington, 90: 536-552. (Available from http://www.biodiversitylibrary.org/item/120622#page/572/mode/1up)
Curran, C.H. 1921. Revision of the Pipiza group of the family Syrphidae (flower-flies) from north of Mexico. Proceedings of the California Academy of Sciences, 11: 345-393. (Available from http://www.biodiversitylibrary.org/page/26481379/#page/361/mode/1up)
Curran, C.H. 1922. The syrphid genera Hammerschmidtia and Brachyopa in Canada. Annals of the Entomological Society of America, 15: 239-255. (Available from http://www.biodiversitylibrary.org/item/44557#page/257/mode/1up)
Curran, C.H. 1924. Synopsis of the genus Chrysotoxum with notes and a description of a new species (Syrphidae, Diptera). Canadian Entomologist, 56: 34-40.
Curran, C.H. 1925a. Revision of the genus Neoascia Williston (Diptera: Syrphidae). Proceedings of the Entomological Society of Washington, 27: 51-62. (Available from http://www.biodiversitylibrary.org/item/54668#page/73/mode/1up)
Curran, C.H. 1925b. Contribution to a monograph of the American Syrphidae from north of Mexico. Kansas University Science Bulletin, 15: 7-216. (Available from http://www.biodiversitylibrary.org/page/4391303/#page/15/mode/1up)
Curran, C.H. 1927. Synopsis of males of the genus Platycheirus St. Fargeau & Serville with descriptions of new Syrphinae (Diptera). American Museum Novitates, 247: 1-13. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/3200/...)
Curran, C.H. 1930a. Report on the Diptera collected at the station for the study of insects, Harriman Interstate Park, N.Y. Bulletin of the American Museum of Natural History, 61: 21-115. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/855/...)
Curran, C. H. 1930b. New species of Volucellinae from America (Syrphidae, Diptera). American Museum Novitates, 413: 1-23. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/3052//v2/...)
Curran, C.H. 1930c. New species of Eristalinae with notes (Syrphidae, Diptera). American Museum Novitates, 411: 1-27. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/4365//v2/...)
Curran, C.H. 1932. New American Syrphidae (Diptera), with notes. American Museum Novitates, 519: 1-9. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2990//v2/...)
Curran, C.H. 1935. New American Diptera. American Museum Novitates, 812: 1-24. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2138//v2/...)
Curran, C.H. 1939a. The species of Temnostoma related to bombylans Linné (Syrphidae, Diptera). American Museum Novitates, 1040: 1-3. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2224//v2/...)
Curran, C. H. 1939b. Synopsis of the American species of Volucella (Syrphidae: Diptera). Part 1. Table of species. American Museum Novitates, 1027: 1-7. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2219//v2/dspace/ingest/pdfSource/nov/N1027.pdf?sequence=1)
Curran, C.H. 1940. Some new Neotropica1 Syrphidae (Diptera). American Museum Novitates, 1086: 1-14. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2238//v2/dspace/ingest/pdfSource/nov/N1086.pdf?sequence=1)
Curran, C.H. 1941. New American Syrphidae. Bulletin of the American Museum of Natural History, 78: 243-304. (Available from http://digitallibrary.amnh.org/dspace/handle/2246/377)
Curran, C.H. 1951. Synopsis of the North American species of Spilomyia (Syrphidae, Diptera). American Museum Novitates, 1492: 1-11. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2364//v2/dspace/ingest/pdfSource/nov/N1492.pdf?sequence=1)
Curran, C.H. 1953. Notes and descriptions of some Mydaidae and Syrphidae. American Museum Novitates, 1645: 1-15. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2413//v2/dspace/ingest/pdfSource/nov/N1645.pdf?sequence=1)
Curran, C.H. and Fluke, C.L., Jr. 1926. Revision of the Nearctic species of Helophilus and allied genera. Transactions of the Wisconsin Academy of Sciences, Arts and Letters, 22: 207-281. (Available from http://images.library.wisc.edu/WI/EFacs/transactions/WT1926/reference/wi.wt1926.chcurran.pdf)
Dusek, J. and Laska, P. 1967. Versuch zum Autbau eines natiirlichen Systems mitteleuropiischer Arten der Unterfamilie Syrphinae (Diptera). Acta Scientiarum Naturalium Academiae Scientiarum Bohemoslovacae, 1: 349-390.
Fluke, C.L., Jr. 1935. Revision of the Epistrophe flies of America north of Mexico (Diptera, Syrphidae). Entomologica Americana, 15: 1-56.
Fluke, C.L., Jr. 1942. Revision of the neotropical Syrphini related to Syrphus (Diptera, Syrphidae). American Museum Novitates, 1201: 1-24. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2279//v2/dspace/ingest/pdfSource/nov/N1201.pdf?sequence=1)
Fluke, C.L., Jr. 1949. Some Alaskan syrphid flies, with descriptions of new species. Proceedings of the United States National Museum, 100: 39-54. (Available from http://www.biodiversitylibrary.org/item/53452#page/55/mode/1up)
Fluke, C.L., Jr. 1952. The Metasyrphus species of North America (Syrphidae). American Museum Novitates, 1590: 1-27. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2398//v2/dspace/ingest/pdfSource/nov/N1590.pdf?sequence=1)
Fluke, C. L ., Jr., and Hull, F.M. 1946. Syrphid flies of the genus Cheilosia, subgenus Chilomyia in North America (Part II). Transactions of the Wisconsin Academy of Sciences, Arts and Letters, 36: 327-347. (Available from http://images.library.wisc.edu/WI/EFacs/transactions/WT1944/reference/wi.wt1944.clfluke.pdf)
Fluke, C.L., Jr. and Weems, H.V., Jr. 1956. The Myoleptini of the Americas (Diptera, Syrphidae). American Museum Novitates, 1758: 1-23. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2452//v2/dspace/ingest/pdfSource/nov/N1758.pdf?sequence=1)
Gilbert, F. 2005a. The evolution of imperfect mimicry. In Insect Evolotionary Ecology. Edited by M.D.E. Fellowes, G.J. Holloway and J. Rolff. CABI, Wallingford, UK, pp. 231-288.
Gilbert, F. 2005b. Syrphid aphidophagous predators in a food-web context. European Journal of Entomology, 102: 325-333. (Available from http://www.eje.cz/pdfarticles/1011/eje_102_3_325_Gilbert.pdf)
Gittings, T., O'Halloran, J., Kelly, T. and Giller, P.S. 2006. The contribution of open spaces to the maintenance of hoverfly (Diptera, Syrphidae) biodiversity in Irish plantation forests. Forest Ecology and Management, 237: 290-300.
Hull, F.M. 1924. Milesia in North America (Dipt.: Syrphidae). Entomological News, 35: 280-282.
Hull, F.M. 1935. Descriptions of new species of the genus Sphegina with a key to those known from North America (Syrphidae: Diptera). Transactions of the American Entomological Society, 61: 373-382. (Available from http://chla.library.cornell.edu/cgi/t/text/pageviewer...)
Hull, F.M. 1942a. The genus Ferdinandea Rondani. Journal of the Washington Academy of Sciences, 32: 239-241. (Available from http://www.biodiversitylibrary.org/item/122709#page/283/mode/1up)
Hull, F.M. 1942b. The flies of the genus Meromacrus (Syrpbidae). American Museum Novitates, 1200: 1-10. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2278//v2/dspace/ingest/pdfSource/nov/N1200.pdf?sequence=1)
Hull, F.M. 1943. The genus Mesogramma. Entomologica Americana, 23: 1-41.
Hull, F.M. 1954. The genus Mixogaster Macquart (Diptera, Syrphidae). American Museum Novitates, 1652: 1-28. (Available from http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2417//v2/dspace/ingest/pdfSource/nov/N1652.pdf?sequence=1)
Hull. F. M., and C. L. Fluke, Jr. 1950. The genus Cheilosia Meigen (Diptera, Syrphidae). The subgenera Cheilosia and Hiatomyia. Bulletin of the American Museum of Natural History, 94: 299-402. (Available from http://digitallibrary.amnh.org/dspace/handle/2246/1001)
Kearns, C.A. 1992. Anthophilous fly distribution across an elevation gradient. American Midland Naturalist, 127: 172-182.
Kevan, P. 2002. Flowers, pollination, and the associated diversity of flies. Biodiversity, 3(4): 16-18.
Knutson, L.V. 1973. Taxonomic revision of the aphid-killing flies of the genus Sphaerophoria in the western hemisphere. Miscellaneous Publications of the Entomological Society of America, 9: 1-50.
Krivosheina, N.P. 2004. The morphology of flies of the Temnostoma apiforme and T. vespiforme groups (Diptera, Syrphidae): Communication II. Entomological Review, 84(1): 100-117.
Larde, G. 1989. Investigation on some factors affecting larval growth in coffee-pulp bed. Biological Wastes, 30: 11-19.
Larson, B.M.H., Inouye, D.W. and P.G. Kevan. 2001. Flies and flowers: I. The taxonomic diversity of anthophiles and pollinators. Canadian Entomologist, 133(4): 439-465.
Latta, R. and Cole, F.R. 1933. A comparative study of the species of Eumerus known as the lesser bulb flies. Monthly Bulletin of the California Department of Agriculture, 22: 142-152.
Locke, M.M. and Skevington, J.H. 2013. Revision of Nearctic Dasysyrphus Enderlein (Diptera: Syrphidae). Zootaxa, 3660: 1-80. (Available from http://www.mapress.com/zootaxa/2013/f/zt03660p080.pdf)
Malloch, J.R. 1922. Keys to the syrphid genus Sphegina Meigen (Dip.). Entomological News, 33: 266-270. (Available from http://www.biodiversitylibrary.org/page/2611158/#page/328/mode/1up)
Marinoni, L., Miranda, G.F.G. and Thompson, F.C. 2004. Abundância e riqueza de espécies de Syrphidae (Diptera) em áreas de borda e interior de floresta no Parque Estadual de Vila Velha, Ponta Grossa, Paraná, BRASIL. Revista Brasileira de Entomologia, 48: 553-559. (Available from http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0085-56262004000400019&lng=en&nrm=iso)
Martin, J.E.H. 1977. The Insects and Arachnids of Canada. Part 1. Collecting, preparing and preserving insects, mites and spiders. Biosystematic Research Institute, Ottawa, Canada. (Available from http://www.esc-sec.ca/aafcmonographs/insects_and_arachnids_part_1_eng.pdf).
Mengual, X. and Thompson, F.C. 2011. Carmine cochineal killers: the flower fly genus Eosalpingogaster Hull (Diptera: Syrphidae) revised. Systematic Entomology, 36(4): 713-731.
Mengual, X., Stahls, G. and Rojo, S. 2008. First phylogeny of predatory flower flies (Diptera, Syrphidae, Syrphinae) using mitochondrial COI and nuclear 28S rRNA genes: conflict and congruence with the current tribal classification. Cladistics, 24(4): 543-562.
Miranda, G.F.G. 2011. An overview of the genus Ocyptamus Macquart, 1834 with a revision of the Ocyptamus tristis species group. PhD, University of Guelph, Canada. (Available from https://atrium.lib.uoguelph.ca/xmlui/handle/10214/3017)
Montoya, A.L., Pérez, S.P. and Wolff, M. 2012. The diversity of flower flies (Diptera: Syrphidae) in Colombia and their neotropical distribution. Neotropical Entomology, 41: 46-56.
Penney, H.D., Hassall, C., Skevington, J.H., Abbott, K.R. and Sherratt, T.N. 2012. A comparative analysis of the evolution of imperfect mimicry. Nature, 483: 461-466.
Rojo, S., Gilbert, F., Marcos-García, M.A., Nieto, J.M. and Mier, M.P. 2003. A world review of predatory hoverflies (Diptera, Syrphidae: Syrphinae) and their prey. CIBIO, Alicante, Spain.
Rotheray, G.E. 1989. Aphid predators. Pelagic Publishing, Exeter, UK.
Sedman, Y.S. 1964. The Chrysogaster (Orthonevra) bellula group in North America (Diptera: Syrphidae). Proceedings of the Entomological Society of Washington, 66: 169-176. (Available from http://www.biodiversitylibrary.org/item/54814#page/527/mode/1up)
Sedman, Y. S. 1966. The Chrysogaster (Orthonevra) pictipennis group in North America (Diptera: Syrpbidae). Proceedings of the Entomological Society of Washington, 68: 185-194. (Available from http://www.biodiversitylibrary.org/item/84949#page/497/mode/1up)
Shannon, R.C. 1916. Notes on some genera of Syrphidae with descriptions of new species. Proceedings of the Entomological Society of Washington, 18: 101-113. (Available from http://www.biodiversitylibrary.org/item/20207#page/119/mode/1up)
Shannon, R.C. 1924. A new Cynorhinella (Syrphidae, Diptera). Occasional Papers of the Boston Society. of Natural History, 5: 123-124. (Available from http://www.biodiversitylibrary.org/item/107543#page/147/mode/1up)
Shannon, R.C. 1925. The Syrphid-flies of the subfamily Ceriodinae in the U.S. National Museum collection. Insecutor Inscitiae Menstruus. 13: 48-65.
Shannon, R.C. 1926a. The chrysotoxine syrphid flies. Proceedings of the United States National Museum, 69: 1-20. (Available from http://www.biodiversitylibrary.org/item/52772#page/419/mode/1up)
Shannon, R.C. 1926b. Review of the American xylotine syrphid-flies. Proceedings of the United States National Museum, 69: 1-52. (Available from http://www.biodiversitylibrary.org/item/52772#page/305/mode/1up)
Shannon. R. C. 1939. Temnostoma bombylans and related species (Syrphidae. Diptera). Proceedings of the Entomological Society of Washington, 41: 215-224. (Available from http://www.biodiversitylibrary.org/item/54651#page/253/mode/1up)
Shorthouse, D.P. 2010. SimpleMappr, a web-enabled tool to produce publication-quality point maps. Available from http://www.simplemappr.net. [accessed 9 December 2011].
Skevington, J.H. and Thompson, F.C. 2012. Review of the New World Sericomyia (Diptera: Syrphidae), including description of a new species. Canadian Entomologist, 144: 1-32.
Sommagio, D. 1999. Syrphidae: can they be used as environmental bioindicators? Agriculture, Ecosystems and Environment, 74: 343-356.
Ssymank, A., Kearns, C.A., Pape, T. and Thompson, F.C. 2008. Pollinating flies (Diptera): A major contribution to plant diversity and agricultural production. Biodiversity, 9(1-2): 86-89.
Stubbs, A.E. and Falk, S.J. 1983. British Hoverflies: An illustrated identification guide. British Entomological and Natural History Society, Cornwall, UK.
Telford, H.S. 1970. Eristalis (Diptera, Syrphidae) from America north of Mexico. Annals of the Entomological Society of America, 63: 1201-1210.
Thompson, F.C. 1972. A contribution to a generic revision of the neotropical Milesinae (Diptera: Syrphidae). Arquivos de Zoologia, 23: 73-215.
Thompson, F.C. 1981. Revisionary notes on Nearctic Microdon flies (Diptera: Syrphidae). Proceedings of the Entomological Society of Washington, 83: 725-758. (Available from http://www.biodiversitylibrary.org/item/55215#page/755/mode/1up)
Thompson, F.C. 1999. A key to the genera of the flower flies (Diptera: Syrphidae) of the Neotropical region including descriptions of new genera and species and a glossary of taxonomic terms. Contributions on Entomology, International, 3: 321-378.
Thompson, F.C. 2010. Syrphidae. Systema Dipterorum. Available from http://www.diptera.org/ [accessed 8 January 2011].
Thompson, F.C. 2012. Fabulous flower flies for famous fly fanatics (Diptera: Syrphidae). A tribute to the dipterists of the Canadian National Collection. Canadian Entomologist, 144: 1-16.
Thompson, F.C., Fee, F.D. and Berzark, L.G. 1990. Two immigrant synanthropic flower flies (Diptera: Syrphidae) new to North America. Entomological News, 101: 69-74.
Thompson, F.C., Rotheray, G.E. and Zumbado, M.A. 2010. Syrphidae. In Manual of Central American Diptera. Edited by B.V. Brown, A. Borkent, J.M. Cumming, D.M. Wood, N.E. Woodley and M.A. Zumbado. NRC Research Press, Ottawa, Canada, pp. 763-792.
Vockeroth, J.R. 1980. A review of the Nearctic species of Melangyna (Meligramma) Frey (Diptera: Syrphidae). Canadian Entomologist, 112: 775-778.
Vockeroth, J.R. 1983. Nomenclatorial notes on Nearctic Syrphinae, with descriptions of new species of Syrphus and keys to the species of Didea. Epistrophe s. str. and Syrphus (Diptera: Syrphidae). Canadian Entomologist, 115: 175-182.
Vockeroth, J.R. 1986. Revision of the New World species of Paragus Latreille (Diptera: Syrphidae). Canadian Entomologist, 118: 183-198.
Vockeroth, J.R. 1992. The flower flies of the subfamily Syrphinae of Canada, Alaska and Greenland. Centre for Land and Biological Resources Research, Ottawa, Canada. (Available from http://esc-sec.ca/aafcmonographs/insects_and_arachnids_part_18.pdf)
Vockeroth, J.R. and Thompson, F.C. 1987. Syrphidae. In Manual of Nearctic Diptera. Edited by J.F. McAlpine, B.V. Peterson, G.E. Shewell, H.J. Teskey, J.R. Vockeroth and D.M. Wood. Research Branch, Agriculture Canada, Ottawa, Canada. pp. 713-743. (Available from http://esc-sec.ca/aafcmonographs/manual_of_nearctic_diptera_vol_2.pdf)
Weems, H.V., Jr., Thompson, F.C., Rotheray, G. and Deyrup, M.A. 2003. The genus Rhopalosyrphus (Diptera: Syrphidae). Florida Entomologist, 86: 186-193. (Available from http://journals.fcla.edu/flaent/article/view/75192/72850)
Weisman. K. E. 1965. The male genitalia of the genus Sphecomyia Latreille (Diptera: Syrphidae). Entomological News, 76: 265-272.
Weisman. K. E. 1966. Distribution of the genus Sphecomyia. Latreille (Diptera: Syrphidae). Entomological News, 77: 50-56.
Williston, S.W. 1887. Synopsis of the North American Syrphidae. Bulletin of the United States National Museum, 31: 1-335. (Available from http://www.biodiversitylibrary.org/item/90715#page/5/mode/1up)
Wirth, W.W., Sedman, Y.S. and Weems, H.V. 1965. Family Syrphidae. In A Catalog of the Diptera of America north of Mexico. Edited by A. Stone, C.W. Sabrosky, W.W. Wirth, R.H. Foote, J.R. Coulson. United States Department of Agriculture, Washington, D.C., U.S.A. pp. 557-625.
Young, A.D. 2012. A revision of the Nearctic species of Platycheirus Lepeletier and Serville (Diptera: Syrphidae). M.Sc., University of Guelph, Canada. (Available from https://atrium.lib.uoguelph.ca/xmlui/handle/10214/3597)
Miranda, G.F.G, Young, A.D., Locke, M.M., Marshall, S.A., Skevington, J.H., Thompson, F.C. 2013. Key to the Genera of Nearctic Syrphidae. Canadian Journal of Arthropod Identification No. 23, 23 August, 2013. Available online at doi: 10.3752/cjai.2013.23