Lasioglossum (Dialictus) dashwoodi 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 : 106-109

Lasioglossum (Dialictus) dashwoodi Gibbs , new species

( Figures 95A–C , 96A–E )

Holotype. ♀ CANADA, British Columbia, Similkameen Reg. Dist. , Oliver, Ripley Lk. N49.2432 W119.6329, 925 m, 12.vii.2008 (L. R. Best); [ PCYU].

Diagnosis. Females of L. dashwoodi can be recognised by the diagnostic combination of a golden green head and mesosoma, wide head (length/width ratio = 0.94), distinctly purplish supraclypeal area smooth and shining integument with coarse moderately sparse punctures (i=1–2.5d) on the mesoscutum and mesepisternum, posterior margins of the dorsolateral slope and metapostnotum rugulose, and metallic metasomal terga with fine punctures on the relatively polished apical impressed areas. They are most similar to L. abundipunctum and L. punctatoventre . Female L. abundipunctum have the posterior margins of the dorsolateral slope and metapostnotum smooth and distinct punctures on the apical impressed areas of the metasomal terga. Female L. punctatoventre have the apical impressed areas of the metasomal terga strongly coriarious. Female L. reasbeckae is also similar but lacks metallic reflections on the metasomal terga.

Males of L. dashwoodi can be recognised by the diagnostic combination of very coarse and relatively sparse mesoscutal and mesepisternal punctures, tarsi brown and metasomal terga metallic.

Description. FEMALE. Length 5.32–6.29 mm; head length 1.58–1.63 mm; head width 1.70–1.73 mm; forewing length 4.36–4.42 mm.

Colouration. Head and mesosoma bluish to golden green. Clypeus with apical 4/5 blackish brown, basal 1/5 brassy. Supraclypeal area purplish-brassy. Antenna dark brown, with ventral surface brownish yellow. Tegula dark, reddish brown. Wing membrane subhyaline, venation and pterostigma honey coloured. Legs brown, medio- and distitarsi brownish red. Metasomal terga weakly metallic green, sterna brown, apical margins broadly reddish brown to translucent yellow.

Pubescence. Dull white. Moderately dense. Head and mesosoma with moderately sparse woolly hairs (1– 1.5 OD), longest on genal beard, metanotum and mesopleuron (2–2.5 OD). Lower paraocular area and gena with sparse tomentum not obscuring surface. Metanotum anteromedial portion with dense tomentum obscuring surface. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with moderately dense, fine setae. T1 acarinarial fan sparse, complete dorsally, intermingled with erect hairs. T2 basolateral and T3–T4 with moderately dense tomentum, partially obscuring surface. T2 apicolateral and T3–T4 apical margins with fringes weak, nearly absent.

Surface sculpture. Face polished, weakly imbricate, punctation coarse. Clypeus with punctation moderately sparse (i=1–2.5d). Supraclypeal area with punctation sparse (i=1–3d). Lower paraocular and antennocular areas with punctation dense (i≤d). Upper paraocular area and frons punctate-reticulate. Ocellocular area irregularly punctate (i=1–2d). Gena shining, weakly striate. Postgena polished, coarsely punctate. Mesoscutum polished, anteromedial portion weakly imbricate, punctation coarse, sparse between parapsidal lines (i=1–2.5d), moderately dense laterad of parapsidal lines (i=1–1.5d), contiguous on anterolateral portions. Mesoscutellum similar to mesoscutum, submedial punctation sparse (i=2–4d). Axilla punctate. Metanotum ruguloso-imbricate. Preëpisternum reticulate-punctate. Hypoepimeral area polished, punctate (i=1–1.5d). Mesepisternum polished, weakly lineolate, coarsely punctate (i=1–1.5d). Metepisternum with dorsal third finely ruguloso-striate, ventral portion reticulate-imbricate. Metapostnotum anastomosingly rugose. Propodeum with dorsolateral slope and lateral and posterior surfaces ruguloso-imbricate. Metasomal terga polished except apical margins coriarious, punctation on basal halves dense (i=1–2d), obscure on apical halves (i=1– 3d).

Structure. Head wide (length/width ratio = 0.93–0.94). Eyes weakly convergent below (UOD/LOD ratio = 1.16–1.17). Clypeus ½ below suborbital tangent, apicolateral margins 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 = 1.13–1.14), posterior margin rounded onto posterior surface. Propodeum with oblique carina weak, obscure, lateral carina widely divergent, not reaching margin of dorsal surface.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 5.32 mm; head length 1.60 mm; head width 1.68 mm; forewing length 3.81 mm.

Colouration. Body bluish with greenish reflections. Supraclypeal area bluish. Flagellum with ventral surface orange-yellow. Medio- and distitarsi reddish brown.

Pubescence. Lower face with sparse tomentum, paritally obscuring surface, denser on lower paraocular area. T1 declivitous surface with fan shaped hairs. T2–T5 with sparse wooly hairs. S2–S4 apicolateral portions with posteromedially directed hair tufts.

Surface sculpture. Supraclypeal area densely punctate (i≤d). Mesoscutal and mesoscutellar punctation sparse (i=1–3d). Apical impressed areas of T2–T4 almost completely impunctate.

Structure. Head moderately wide to round (length/width ratio = 0.95). Eyes strongly convergent below (UOD /LOD ratio = 1.43). Antennal sockets distant (IAD/OAD> 1.4). Pedicel shorter than F1. F2 length 1.8X F1. F2–F10 (length/width ratio = 1.56–1.79). Metapostnotum moderately elongate (MMR ratio = 1.29), posterior margin narrowly rounded onto posterior surface.

Terminalia . S7 median lobe narrowly clavate ( Fig. 96D ). S8 apical margin weakly concave ( Fig. 96D ). Genitalia as in Fig. 96D–F, H . Gonobase with ventral arms narrowly separated. Gonostylus small, dorsal setae elongate. Retrorse lobes elongate, attenuated apically ( Fig. 96D ).

Range. British Columbia south to Washington ( Fig. 94 )

Allotype. USA: WASHINGTON: ♂ Okanogan Co., 1 mi E Muckamuck Hill, 11U E296155 N5386867, 9.viii.2004 (J. Wilson); [ BBSL / PCYU].

Paratypes. CANADA: BRITISH COLUMBIA: 1♀ topotypical, 11.vii.2008 (L. R. Best); [ PCYU] ; USA: WASHINGTON: 1♀ Garfield Co., 25 km W Clarkston, Hwy 12, 805 m, 29.v.2007 (Gibbs & Sheffield); [ PCYU] .

Etymology. The specific epithet is named for George Dashwood, Sr., a British Columbian conservationist. The collector of the holotype, Lincoln Best, was supported in his bee collecting efforts by Mr. Dashwood. Comments. Uncommon. See comments for L. punctatoventre (below).

Figures

FIGURE 94. Distribution of Lasioglossum cressonii, (light grey) and L. dashwoodi (dark grey).

FIGURE 95. Lasioglossum dashwoodi new species. Female (A) lateral habitus; (B) dorsal habitus; (C) face. Scale bars, A–C = 1 mm.

FIGURE 96. Lasioglossum dashwoodi new species. Male (A) lateral habitus; (B) dorsal habitus; (C) face; (D) ventral view of genital capsule; (E) dorsal view of genital capsule. Scale bars, A–C = 1 mm, E = 0.5 mm.