Lasioglossum (Dialictus) punctatoventre (Crawford)

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 273-276

Lasioglossum (Dialictus) punctatoventre (Crawford)

( Figure 192A–D )

Halictus punctatoventris Crawford, 1907: 196 . ♀ ♂. Holotype. ♀ USA, California, Claremont (Baker) ; [NMNH: 12078]

Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) punctatoventre , p. 1117 (catalogue); Dialictus punctatoventris , p. 1971 (catalogue); Moure & Hurd, 1987: Dialictus punctatoventris , p. 126 (catalogue).

Diagnosis. Females of L. punctatoventre can be recognised by the diagnostic combination of a wide head (length/width ratio = 0.93–0.95), smooth and shining integument with coarse moderately sparse punctures (i=1–2d) on the mesoscutum and mesepisternum, and relatively less dense punctures on the the apical impressed areas of the metasomal terga. Lasioglossum abundipunctum and L. dashwoodi are most similar but have more distinct punctures on the apical impressed areas of the metasomal terga. Lasioglossum reasbeckae is also similar but is golden green with a purplish supraclypeal area and has obscure punctures on the apical impressed areas of the metasomal terga.

Male unknown.

Description. FEMALE. Length 5.08–5.14 mm; head length 1.48–1.50 mm; head width 1.56–1.62 mm; forewing length 3.93–3.99 mm.

Colouration. Head and mesosoma blue-green with brassy reflections. Clypeus with apical 4/5 blackish brown, basal 1/5 and supraclypeal area brassy. Antenna dark brown, F7–F10 with ventral surface reddish. Tegula dark, reddish brown to amber. Wing membrane subhyaline, venation and pterostigma amber. Legs brown, medio- and distitarsi brownish red. Metasoma dark brown, terga and sterna with apical margins translucent yellow.

Pubescence. Dull white. Mostly sparse. Head and mesosoma with moderately sparse woolly hairs (1–2 OD), longest on genal beard, metanotum and mesopleuron (2–2.5 OD). Lower paraocular area and gena with sparse subappressed tomentum. Propodeum with plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with very sparse, fine setae. T1 acarinarial fan sparse, complete dorsally. T2 basolaterally and T3 basally with tomentum. T3–T4 entirely with scattered tomentum. T2 apicolaterally and T3–T4 apical margins with very sparse fringes.

Surface sculpture. Face polished, weakly imbricate, punctation strong. Clypeal punctation moderately sparse (i=1–3d). Supraclypeal area with punctation moderately sparse (i=1–2d). Lower paraocular area punctation dense (i≤d). Antennocular area punctation moderately dense (i<1.5d). Upper paraocular area and frons punctate-reticulate. Ocellocular area minutely punctate (i=d). Gena shining, faintly lineolate. Postgena polished, coarsely punctate. Mesoscutum polished, anteromedial portion weakly imbricate, punctation coarse, moderately sparse between parapsidal lines (i=1–2d), closer but not dense laterad of parapsidal lines or anterolateral portions (i=1d). Mesoscutellum similar to mesoscutum, submedial punctation sparse (i=2–4d), medial punctation minute, sparse (i=1–2d). Axilla punctate. Metanotum polished, obscurely punctate. Preëpisternum reticulate-punctate. Hypoepimeral area polished, punctate (i=1–1.5d). Mesepisternum polished and shining, coarsely punctate (i=1–1.5d). Metepisternum with dorsal third finely ruguloso-striate, ventral portion finely reticulate. Metapostnotum anastomosingly rugose almost reaching posterior margin, posterior margin smooth. Propodeum with lateral surface imbricate-rugulose, posterior surface tessellate. Metasomal terga polished, punctation strong (i=1–2d), less distinct on apical impressed areas.

Structure. Head wide (length/width ratio = 0.93–0.95). Eyes weakly convergent below (UOD/LOD ratio = 1.06–1.08). Clypeus ½ below suborbital tangent, apicolateral margins strongly convergent. Antennal sockets close (IAD/OAD <0.5). Frontal line carinate, ending 2.5 OD below median ocellus. Gena narrower than eye. Inner metatibial spur pectinate with 3–4 teeth. Metapostnotum moderately elongate (MMR ratio = 1.19–1.23), posterior margin smoothly rounded onto posterior surface. Propodeum with oblique carina weak, obscure, lateral carina widely divergent, not reaching margin of dorsal surface.

MALE. Unknown.

Range. Southern California to Northern Washington ( Fig. 191 ).

Additional material examined. CANADA: BRITISH COLUMBIA: 1♀ Okanagan-Similkameen Reg. Dist., Mt. Oliver , N49.2429 W119.6326, 935 m, 4.v.2008 (L. R. Best) ; 1♀ Okanagan-Similkameen Reg. Dist., Willowbrook , N49.2698 W119.6029, 453 m, 31.v.2008 (L. R. Best); [ PCYU] ; USA: CALIFORNIA : 1♀ Los Angeles Co., N34.0974 W118.8134, 30–31.v.2008 (S.W. Droege); [ PCYU] ; 2♀ Mariposa Co., 1.9 mi SE Ostrander Rocks , 2104 m, 11S E273401 N417529, 18–19.vii.2005 (H. Ikerd & E. Stephens); [ BBSL / PCYU] ; 1♀ Siskiyou Co., Hwy 89, N41.25601 W122.03987, 1044 m, 3.vii.2007 (Gibbs & Sheffield); [ PCYU] ; 1♀ Westwood , 17.vi.1959 (Kelton & Madge); [ CNC]; IDAHO : 1♀ Blaine Co., Ketchum, Sawtooth Bot. Gard. , 1726 m, 24.vi.2007 (Gibbs & Sheffield); [ PCYU] .

Comments. The holotype of L. punctatoventre is missing the metasoma. The characters of the metasomal terga are important for distinguishing between L. punctatoventre and related species. As a result there is some uncertainty if the names have been applied correctly. At this point, only one of these closely related species has a known range which includes the type locality of L. punctatoventre . This is in part the reason for ascribing the name L. punctatoventre as I have done.

Crawford (1907) included a description of the male. I have not examined any material that I can confidently identify as the male of this species. Distinguishing the male of L. punctatoventre from those of similar species described here will likely be difficult without DNA sequences.

Figures

FIGURE 191. Distribution of Lasioglossum pruinosum (light grey) and L. punctatoventre (dark grey).

FIGURE 192. Lasioglossum punctatoventre (Crawford). Female (A) lateral habitus; (B) dorsal habitus; (C) face. Scale bars, A–C = 1 mm.