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Siricidae (Hymenoptera: Symphyta: Siricoidea) of the Western Hemisphere
CJAI 21, July, 2012
doi: 10.3752/cjai.2012.21
Nathan M. Schiff, Henri Goulet, David R. Smith, Caroline Boudreault, A. Dan Wilson, and Brian E. Scheffler

Urocerus californicus Norton

Fig. C22.1, Schiff et al. 2006: 64, 65 (female habitus)
Fig. C22.2, Schiff et al. 2006: 63 (male habitus)
Fig. C22.6 (map)

Urocerus albicornis var. californicus Norton, 1869: 360, Ries 1951: 84, Smith 1979: 128. Norton described a female as this variety of U. albicornis, but gives no locality or number of specimens. California is not listed in the distribution of U. albicornis and no specimens were located (the name is not mentioned in Cresson 1928: 10, 11). Type locality: perhaps California. There is no evidence that the name was either subspecific or infrasubspecific in the original text. The name, californicus, suggests a geographical variant of the species. The description is also clearly diagnostic. Therefore, we consider this name as subspecific and valid.
Urocerus fulvus Cresson, 1880: 35. Lectotype male (ANSP) designated by Cresson 1916, seen by DRS; Cresson, 1916: 10. Synonym by Bradley 1913: 20; accepted by Ries 1951: 84, Smith 1979: 128, Smith 1988: 242. Type locality: Colorado.
Sirex flavipennis Kirby, 1882: 380, pl. XV, fig. 10. Holotype female (BMNH), not examined. Synonym by Bradley 1913: 20; accepted by Ries 1951: 84, Smith 1979: 128, Smith 1988: 242. Type locality: “Vancouver’s Island”.
Sirex fulvus; Kirby, 1882: 379 (change in combination).
Urocerus californicus; Bradley, 1913: 20 (change in rank); accepted by Ries 1951: 84, Smith 1979: 128, Smith 1988: 242.

Diagnostic Combination

Among females females with a completely or almost completely black abdomen, including cornus [albicornis], those of U. californicus are recognized by the completely white flagellum and clearly yellow tinted wings. Males of U. californicus are recognized by the almost completely light reddish brown body and the brown or reddish brown legs.



Color. Head black except for white spot behind eye. Maxillary palp and mandible black. Scape black or brown (rarely as pale as flagellum), and pedicel as pale as flagellum or a little darker; flagellum white or yellowish (Fig. B4.29). Thorax black. Legs black but white on basal 0.25–0.6 of tibiae (usually more on protibia than on metatibia) and on tarsomeres 1. Fore and hind wings clearly yellow tinted (Fig. B4.31). Abdomen black, or in a few specimens with a white spot laterally on tergum 8 (as in Fig. B4.19).

Head. Vertex densely pitted between the white genal spots (as in Fig. B4.47).

Thorax. Metatarsomere 2 in lateral view about 4.0 times as long as high (Fig. B4.33), and its tarsal pad about 0.8 as long as ventral length of tarsomere.

Abdomen. Median basin of tergum 9 with base (outlined by two lateral black longitudinal furrows) 1.7 times as wide as median length, with maximum width 1.6–1.8 times as wide as median length, and with median length 0.3–0.4 times as long as cornus length. Cornus in dorsal view constricted near base, and minimum width of constriction 0.7–0.9 times as wide as maximum width subapically. Tergum 8 with microsculpture of sublateral surface (between spiracle and pitted sculpticells on central area) smooth and without meshes (except near spiracle); tergum 9 with dorsal surface lateral to median basin smooth and without meshes, ventral surface with meshes, and sculpticells flat and hardly elevated posteriorly. Sheath. Length 0.8–1.0 time length of fore wing; apical section 1.25–1.67 times as long as basal section. Ovipositor. Lancet with 25–32 annuli (annuli in basal 0.5 of lancet outlined but difficult to see (Fig. C22.3)); junction of basal and apical sections of sheath aligned between 5th and 6th or 6th and 7th annuli (Fig. C22.4); apical part of lancet with 13–19 pits. Pits 0.2–0.3 times as long as an annulus, becoming gradually small, and disappearing in basal 0.15–0.4 of apical section of sheath; edge of last 8–12 annuli before teeth annuli extending as ridge to ventral margin of lancet (Fig. C22.5).


Color. Body mainly light reddish brown (Fig. B4.61 abdomen). Gena from lowest edge of eye to postocellar furrow white (Fig. B4.57). Legs light reddish brown, but brown on coxae, femora, apical 0.7 of mesotibia, metatibia, and most of meso- and metatarsomeres 1–3 (Fig. B4.59, hind leg). Fore and hind wings clearly yellow tinted.

Head. Vertex densely pitted between the white genal spots (Fig. B4.55).

Thorax. Metatibia 4.4–6.2 times as long as maximum width. Metatarsomere 1 in lateral view 4.0–5.0 as long as maximum height (Fig. B4.59).

Taxonomic Notes

The types of Urocerus albicornis var. californicus and Urocerus flavipennis were not examined, but their descriptions (especially the fore wing color pattern) match our concept of this species.

The females of this species and U. albicornis are similarly colored, but both species occur sympatrically in southern British Columbia and nearby Washington, without any intermediate specimens. Adults are easily distinguished as outlined in the diagnostic combination.

Hosts and Phenology

The host range of U. californicus is very wide (Essig 1926, Bedard 1938, Benson 1945, Middlekauff 1960, Cameron 1965, Morris 1967, Kirk 1975, Smith, 1979: 128). Based on 109 reared and confirmed specimens, all hosts are Pinaceae: Abies balsamea, A. concolor (104), A. lasiocarpa, A. magnifica, A. nobilis, Larix occidentalis, Calocedrus decurrens, Picea engelmanni, P. sitchensis, Pinus sp. (1), P. contorta, P. lambertiana, P. monticola, P. ponderosa, Pseudotsuga menziesii (3), and Tsuga heterophylla (Morris 1967).

Based on 25 field-collected specimens, the earliest and latest capture dates are April 30 and early November. The main flight period is from the second half of July to the end of September with a peak in August.


CANADA: BC. MEXICO: Hidalgo, Parque Nacional El Chico (specimen not seen; data from correspondence with R. L. Westcott). USA: CA (Middlekauff 1960), CO, ID, MT, NV, OR, UT, WA. Urocerus californicus, a western North American species, is recorded from southern British Columbia to northwestern Mexico (Fig. C22.6). Cameron (1883) and Middlekauff (1960) also mention Mexico without a specific locality, in addition to the record above. A few specimens were recorded from lumber in eastern North America (Burks 1967). One intercepted specimen was reported from England (Benson 1945), and one female from Port Angeles, WA, was intercepted in Osaka, Japan (Okutani 1965).

Specimens studied and included for the distribution map: 341 females and 75 males from BYUC, CNC, NCSU, NFRC, OSAC, UAMC, UASM, UCRC, USFS–GA, and USNM.

Specimens for molecular studies: 14 specimens. See Fig. E2.4b.

CANADA. British Columbia: 2006, CBHR 420, 658. USA. California: 2005, CBHR 97, 658; 1999, CBHR 99, 658; 1999, CBHR 100, 658. Idaho: 2008, CBHR 1354, 493. Montana: 2006, CBHR 371, 658. Oregon: 2003, CBHR 2, 658; 2003, CBHR 10, 658; 2007, CNCS 1071, 649. Washington: 2005, CBHR 212, 658; 2005, CBHR 237, 658; 2005, CBHR 253, 573; 2005, CBHR 257, 658; 2007, CNCS 1070, 596.