Lasioglossum (Dialictus) albohirtum (Crawford)

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 61-65

Lasioglossum (Dialictus) albohirtum (Crawford)

( Figures 68A–C , 69A–F )

Halictus albohirtus Crawford, 1907: 193 . ♀.

Holotype. ♀ USA, Nevada, Ormsby Co, July (Baker); [ NMNH: (1)2068]. Examined.

Halictus pilosellus Cockerell, 1936: 160 . ♀. [new synonymy]

Holotype. ♀ California, Garberville, Humboldt Co. , 19.iv.1935 on Cercocarpus, (T.D.A. Cockerell) ; [ CAS: 4276]. Examined.

Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) albohirtum , p. 1111, L. (C.) pilosellum , p. 1116 (catalogue); Hurd, 1979: Dialictus albohirtus , p. 1964, D. pilosellus , p. 1970 (catalogue); Moure & Hurd, 1987: Dialictus albohirtus , p. 89, D. pilosellus , p. 123 (catalogue).

Diagnosis. Females of L. albohirtum are recognisable by the diagnostic combination of very abundant white pubescence which obscures large parts of head, mesosoma and metasomal terga, round head (length/ width ratio = 0.96–1.00), metallic golden colouration of head and mesosoma and metallic green colouration of metasomal terga, hyaline wings with very pale venation, and distinct mesepisternal punctures. They are similar to L. hyalinum which has a bluish green head and mesosoma and a brown metasoma. Two undescribed species in the Western USA are the most similar to L. albohirtum . One of these has a yellowish brown clypeus and even more abundant pubescence. The other undescribed species is less pubescent and has the mesoscutum more imbricate.

Males of L. albohirtum are similar to females but have more elongate heads (length/width ratio = 1.00– 1.03) and may be further distinguished by the more abundant facial pubescence, moderately elongate flagellomeres (length/width ratio = 1.42–1.70) with bright yellow ventral surfaces, and yellow tarsi. Male L. hyalinum are most similar but have brown metasomal terga.

Redescription. FEMALE. Length 5.37–6.83 mm; head length 1.56–1.73 mm; head width 1.61–1.78 mm; forewing length 3.97–4.45 mm.

Colouration. Head and mesosoma golden green. Labrum reddish brown. Mandible orange. Clypeus with apical half blackish brown, basal half and supraclypeal area brassy. Antenna dark brown, flagellum with ventral surface orange-yellow. Mesoscutum with brassy reflections. Tegula pale, translucent amber. Wing membrane hyaline, venation and pterostigma pale brownish yellow. Legs brown, tibial bases and apices, and tarsi yellow-amber, meso- and metatarsi suffused with brown. Metasomal terga green, apical impressed areas pale translucent brownish yellow, often with darker, subapical, amber transverse stripe, sterna brown.

Pubescence. White. Extremely abundant. Head and mesosoma with dense woolly hairs (1–2 OD), longest on genal beard, metanotum and mesopleuron (2–2.5 OD). Paraocular area, gena, pronotum dorsolateral angle and lobe, lateral margins of mesoscutum, metanotum, metepisternum, and propodeum with lateral surface obscured by tomentum. Propodeum with dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasoma with dense, fine setae. T1 acarinarial fan wide and complete. T1 antero- and dorsolateral areas, T2 basal and lateral portions, and T3–T5 with dense tomentum. T3–T4 apical margins with sparse fringes.

Surface sculpture. Face polished, punctation fine and deep. Clypeal punctation moderately sparse (i=1– 3d). Supraclypeal area with punctation moderately sparse (i=1–2d). Lower paraocular and antennocular areas with punctation dense (i≤d). Upper paraocular area and frons punctate-reticulate. Ocellocular area minutely punctate (i=d). Gena and postgena polished. Mesoscutum polished, punctation fine and deep, evenly spaced (i=1–2d), dense on anterolateral portion (i≤d). Mesoscutellum similar to mesoscutum with additional minute punctures, submedial punctation moderately sparse (i=1–2d). Axilla punctate. Metanotum weakly imbricate, obscurely punctate. Preëpisternum reticulate-punctate. Hypoepimeral area punctate (i≤d). Mesepisternum polished, punctation irregular (i≤d), more widely spaced on ventrally reflexed portion. Metepisternum with dorsal third ruguloso-striate and ventral portion imbricate. Metapostnotum anastomosingly rugoso-striate, posterior margin polished. Propodeum with dorsolateral slope and posterior surface ruguloso-imbricate, lateral surface tessellate-imbricate. Metasomal terga polished, punctation dense throughout (i=1–2d).

Structure. Head wide to round (length/width ratio = 0.96–1.00). Eyes weakly convergent below (UOD/ LOD ratio = 1.09–1.13). Clypeus 2/3–3/4 below suborbital tangent, apicolateral margins convergent. Antennal sockets close (IAD/OAD = 0.5). Frontal line carinate, ending 2 OD below median ocellus. Gena nearly as wide as eye. Inner metatibial spur pectinate with 3–4 teeth. Metapostnotum moderately elongate (MMR ratio = 1.15–1.38), posterior margin rounded onto posterior surface. Propodeum with oblique carina virtually absent, lateral carina weak, reaching halfway to dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 5.06– 5.19 mm; head length 1.39–1.49 mm; head width 1.38–1.45 mm; forewing length 3.60–3.72 mm.

Colouration. Mandible yellow, apex red, base blackish brown. Flagellum with ventral surface yellow. Tibial bases and apices, and tarsi yellow.

Pubescence. Face below eye emargination dense obscuring surface, less abundant on lower clypeus. S2– S3 and S4 lateral portions with moderately dense erect hairs (1.5–2 OD).

Surface sculpture. Propodeum with dorsolateral slope and posterior surface strongly punctate (i≤d), lateral surface ruguloso-reticulate. Metasomal terga apical impressed areas virtually impunctate.

Structure. Head round to moderately elongate (length/width ratio = 1.00–1.03). Eyes weakly convergent below (UOD/LOD ratio = 1.36–1.37). Clypeus 1/2–2/3 below suborbital tangent, apicolateral margins convergent. Antennal sockets close (IAD/OAD> 1.1). Frontal line carinate, ending 2 OD below median ocellus. Pedicel shorter than F1. F2 length 1.7–1.9X F1. F2–F10 moderately elongate (length/width ratio = 1.42–1.70). Metapostnotum elongate (MMR ratio = 1.13–1.19), posterior margin rounded onto posterior surface. Propodeum with oblique carina virtually absent, lateral carina short, not reaching dorsal margin.

Terminalia . S7 with median lobe clavate, apex rounded ( Fig. 69F ). S8 with apicomedial margin weakly convex ( Fig. 69F ). Genitalia as in Fig. 69D–E . Gonobase with ventral arms widely separated. Gonostylus moderately large. Retrorse lobes narrow, weakly attenuated apically. Penis valve narrow.

Range. Saskatchewan to British Columbia, south to Nevada and California ( Fig. 70 ).

Additional material examined. CANADA: ALBERTA: 1♀ 15 km S Three Hills, Hwy 21, N51.49484 W113.23214, 702 m, 15.vi.2007 (Gibbs & Sheffield) ; 1♀ Grassy Lake , 25.v.1988 (L. Packer) ; 1♂ Medicine Hat , N50.00139 W110.64414, 725 m, 2.ix.2007 (Gibbs & Sheffield) ; 4♀ nr Painting on Stone , N49.09251 W111.62146, 929 m, 20.vi.2007 (Gibbs & Sheffield); [ PCYU] ; BRITISH COLUMBIA: 1♂ Cache Creek, 13.5 km west, Hwy 1 at pond, 1550 ft., 6.ix.1989 (C.S. Guppy) ; 1♀ Penticton, West Bench , 15.vii.1986 ( R. A. Cannings) ; 1♂ Penticton, West Bench , 19.vii.1986 ( R. A. Cannings) ; 1♀ Penticton, West Bench , 24.v.1987 ( R. A. Cannings) ; 1♀ Penticton, West Bench , 26.v.1987 ( R. A. Cannings) ; 1♀ Penticton, West Bench , 27.v.1987 ( R. A. Cannings); [ RBCM] ; SASKATCHEWAN: 1♀ Swift Current , 17.ix.1940, (A. R. Brooks); [ CNC] ; USA: CALIFORNIA : 1♀ Humboldt Co., N40.471 W123.86487, 149 m, 4.viii.2007 (Gibbs & Sheffield) ; MONTANA: 4♀, N45.83047 W111.89641, 1314 m, 22.vi.2007 (Gibbs & Sheffield) ; OREGON: 4♀ 1♂ W of Eugene , N42.38352, W122.39975, 2.vii.2007, (Gibbs & Sheffield) ; WASHINGTON: 1♀ Columbia Co., 10 km E Starbuck , HWY 261, N46.50746 W118.03662, 461 m, 29.v.2007 (Gibbs & Sheffield) ; 1♀ Yakima Co., 5 km W Yakima , HWY 12, 130 m, 30.v.2007 (Gibbs & Sheffield); [ PCYU] .

Floral records. ASTERACEAE : Ericameria nauseosa , FABACEAE : Melilotus officinalis , POLYGO- NACEAE: Eriogonum .

Comments. Uncommon.

Figures

FIGURE 68. Lasioglossum albohirtum (Crawford). Female (A) lateral habitus; (B) dorsal habitus; (C) face. Scale bars, A–C = 1 mm.

FIGURE 69. Lasioglossum albohirtum (Crawford). Male (A) lateral habitus; (B) dorsal habitus; (C) face; (D) ventral view of genital capsule; (E) dorsal view of genital capsule; (F) S7, S8. Scale bars, A–C = 1 mm, F = 0.5 mm.

FIGURE 70. Distribution of Lasioglossum albohirtum (dark grey) and L. anomalum (light grey).