Lasioglossum (Dialictus) prasinogaster Gibbs, 2010

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 265-269

Lasioglossum (Dialictus) prasinogaster Gibbs , new species

( Figures 187A–D , 188A–F )

Holotype. ♀ CANADA, Alberta, CFB Suffield, Fish Creek , N50°23.224´W110°36.586´, 29.vi.1994 (Finnamore & Pollock); [ PCYU].

Diagnosis. Females of L. prasinogaster can be recognised by the diagnostic combination of a relatively round to long head (length/width ratio = 0.97–1.03), weakly lineolate gena and polished postgena, dense mesoscutal punctures except submedially (i=1–1.5d), strong and dense mesepisternal punctures ( Fig. 35A ), metapostnotum rugoso-striate except posterior margin smooth, and distinctly green metasomal terga. They are very similar to L. sedi , L. sandhousiellum and the American species L. veganum (Cockerell) which all have relatively minute mesepisternal punctures ( Fig. 35B ).

Males of L. sedi can be recognised by the moderately elongate head (length/width ratio = 1.01–1.03), facial tomentum dense below eye emargination except on clypeus, flagellomeres moderately long (length/ width ratio = 1.42–1.70) 1.27–1.50) with the ventral surface brownish yellow, deep mesoscutal punctures moderately sparse on central disc (i=1–2d), hypoepimeral area and mesepisternum polished due to lack of microsculpture with deep punctures (i≤d), hyaline wings with pale pterostigma, tarsi brownish yellow, and metasomal terga distinctly punctate except apical margins impunctate. They are similar to L. sandhousiellum and L. sedi . Male L. sandhousiellum have sparse mesoscutal punctures on posterior half of central disc (i=1– 4d) and the apical impressed areas of the metasomal terga impunctate. Male L. sedi have facial tomentum limited to paraocular area, reddish brown pterostigma, and pale brown tarsi.

Description. FEMALE. Length 4.27–5.31 mm; head length 1.44–1.54 mm; head width 1.40–1.58 mm; forewing length 3.48–3.90 mm.

Colouration. Head and mesosoma green with golden reflections. Clypeus with apical half blackish brown and basal half, and supraclypeal area bronze, central area purplish. Antenna dark brown, F2–F10 with ventral surface yellow. Mesepisternum and metapostnotum sometimes bluish. Tegula yellowish brown. Wing membrane subhyaline, venation and pterostigma pale brownish yellow. Legs brown, medio- and distitarsi reddish brown to orange-yellow. Metasoma terga green, sterna brown, terga and sterna with apical margins pale brownish red to pale yellow.

Pubescence. Dull white. Moderately dense. Head and mesosoma with dense woolly hairs (1–1.5 OD), longest on genal beard, metanotum and mesopleuron (2–2.5 OD). Lower paraocular area and gena with subappressed pubescence partially obscuring surface. Metepisternum moderately obscured by tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with moderately sparse, fine setae. T1 acarinarial fan weak, complete dorsally. T1 dorsolaterally, T2 basolaterally, and T3–T5 entirely with tomentum extensively obscuring surface. T2 apicolateral and T3–T4 apical margins with weak fringes.

Surface sculpture. Face imbricate, punctation strong. Clypeus polished, punctation sparse (i=1–3d). Supraclypeal area central portion polished, punctation sparse (i=1–3d). Lower paraocular and antennocular areas with punctation dense (i≤1d). Upper paraocular area, frons and ocellocular area punctate-reticulate. Ocellocular area densely punctate (i≤d). Gena weakly lineolate-punctate. Postgena polished. Mesoscutum weakly imbricate medially, polished or weakly imbricate laterally, punctation strong, dense between parapsidal lines (i≤1d), moderately dense on submedial area (i=1–1.5d), dense laterad and mesad of parapsidal lines (i<d), contiguous on anterolateral portion. Mesoscutellum similar to mesoscutum, submedial punctation moderately dense (i=1–2d). Axilla punctate. Preëpisternum weakly reticulate. Hypoepimeral area reticulate-punctate. Mesepisternum polished, punctation moderately coarse, finer below, dense on dorsal half (i≤d). Metepisternum with dorsal quarter striate and ventral portion rugulose. Metapostnotum longitudinally rugoso-striate, posterior margin weakly imbricate. Propodeum with dorsolateral slope polished, weakly imbricate, lateral surface rugulose-tessellate, posterior surface imbricate. Metasomal terga polished, punctation moderately dense (i=1–1.5d), sparse on apical impressed areas (i=2d).

Structure. Head moderately wide to moderately elongate (length/width ratio = 0.97–1.03). Eyes weakly convergent below (UOD/LOD ratio = 1.08–1.11). Clypeus projecting 4/5 below suborbital line, apicolateral margins strongly convergent. Antennal sockets close (IAD/OAD ratio <0.5). Frontal line carinate, ending 2 OD below median ocellus. OOD greater than IOD. Gena narrower than eye. Inner metatibial spur pectinate with 3 teeth. Metapostnotum moderately elongate (MMR ratio = 1.27–1.30), posterior margin rounded onto posterior surface. Propodeum with oblique carina weak, lateral carina divergent, not reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 4.03– 4.58 mm; head length 1.42–1.44 mm; head width 1.39 mm; forewing length 3.42–3.54 mm.

Colouration. Mandible yellow, apex red, base brown. Flagellum with ventral surface bright yelloworange. Tarsi brownish yellow.

Pubescence. Face below eye emargination clothed in moderately dense tomentum, partially obscuring surface. Lower paraocular with very dense tomentum, obscuring surface. Gena with sparse tomentum. T2–T5 with sparse tomentum. S2–S3 with moderately dense, erect hairs (1–1.5 OD).

Surface sculpture. Mesoscutum polished, punctation widely spaced on submedial area of disc (i=2–5d). Mesepisternum polished, punctation distinct (i=d). Propodeum dorsolateral slope, lateral and posterior surfaces punctate (i≤d). Metasomal terga punctation moderately sparse throughout (i=1.5–2.5d), including apical impressed areas.

Structure. Head moderately elongate (length/width ratio = 1.01–1.03). Eyes convergent below (UOD/ LOD ratio = 1.26). Clypeus projecting 2/3 below suborbital line, apicolateral margins weakly convergent. Antennal sockets distant (IAD/ AOD ratio> 1.2). Frontal line carinate, ending 1.5 OD below median ocellus. OOD greater than IOD. Pedicel subequal to F1. F2 length 1.6–1.8X F1. F2–F10 moderately elongate (length/ width ratio = 1.42–1.70). Metapostnotum moderately elongate (MMR ratio = 1.10–1.33), posterior margin rounded onto posterior surface.

Terminalia . S7 with median lobe clavate, sides subparallel, apex rounded ( Fig. 188F ). Genitalia as in Fig. 188D–E . Gonobase with ventral arms narrowly separated. Gonostylus moderately large. Retrorse lobe narrow, strongly attenuated apically. Penis valve slender.

Range. Alberta, British Columbia south to Washington and Colorado ( Fig. 186 ).

Allotype. CANADA: BRITISH COLUMBIA: 1♂ Okanagan-Similkameen Reg. Dist. , Oliver, Ripley Lk., N49.2429 W119.6338, 925 m, 11.vii.2008 (L. R. Best); [ PCYU].

Paratypes. CANADA: ALBERTA: 1♀ 10 km E Raymond, Junct. Hwy 4 & 52, N49.46363 W112.45617, 962 m, (Gibbs & Sheffield) ; 1♂ Medicine Hat , N50.00139 W110.64414, 725 m, 2.ix.2007 (Gibbs & Sheffield); [ PCYU] ; 2♀♀ Waterton Lakes N.P., Cardston Ent. , 3–17.viii.2000; [ BDUC] ; BRITISH COLUMBIA: 1♂ Okanagan-Similkameen Reg. Dist., Osoyoos, Kruger , Strawberry Crk. Rd. , N49.0296 W119.4925, 415 m, 7.viii.2008 (L. R. Best) ; 1♀ 1♂ Okanagan-Similkameen Reg. Dist., Summerland , Garnet Lk., N49.6879 W119.7761, 650 m, 18.vii.2008 (L. R. Best); [ PCYU] ; 1♀ Penticton, West Bench , 12.vi.1982 ( R. A. Cannings) ; 1♀ Summerland , Ag. Canada Res. Stn. , 1.vii.1990 ( R. A. Cannings & H. Nadel); [ RBCM]; SAS- KATCHEWAN: 2♀♀ 28.iv.1949 (A. R. Brooks) ; 1♂ Saskatoon , 15.viii.1940 (A. R. Brooks); [ CNC] ; USA: COLORADO: 6♀♀ Jackson Co., N40.6017 W106.0726, 11–12.v.2004 (S.W. Droege) ; MONTANA: 1♀ Pondera Co., Oil Field Rd. , N48.10142 W112.05304, 1135 m, 21.vi.2007 (Gibbs & Sheffield) ; UTAH: 1♂ Garfield Co., McClellan Spring , 0.5 mi NE, 12S N4214231 E513757, 12.vii.2002 (J. Richmond) ;

WASHINGTON: 2♀♀ Garfield Co., 10 km S Dodge, Hwy 12, 461 m, 29.v.2007 (Gibbs & Sheffield) ; [PCYU].

Etymology. The specific epithet combines the Greek “ prasinos ” and “ gaster ” and refers to the green metasoma of this species.

Floral records. ASTERACEAE : Taraxacum .

Comments. Common.

Figures

FIGURE 35. Mesopleuron of female Dialictus (A) moderately coarse, L. prasinogaster, (B) fine, L. sedi.

FIGURE 186. Distribution of Lasioglossum platyparium (light grey) and L. prasinogaster (dark grey).

FIGURE 187. Lasioglossum prasinogaster new species. Female (A) lateral habitus; (B) dorsal habitus; (C) face; (D) mesepisternum. Scale bars, A–C = 1 mm.

FIGURE 188. Lasioglossum prasinogaster new species. 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.