Lasioglossum (Dialictus) knereri 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 : 166-170

Lasioglossum (Dialictus) knereri Gibbs , new species

( Figures 130A–C , 131A–F )

Holotype. ♀ CANADA, British Columbia, 1♀ Richmond , N49°08´41´´ W123°04´24´´ 14.v.2003 (C. Ratti); [ PCYU].

Diagnosis. Females of L. knereri can be recognised by the diagnostic combination of a wide head (length/ width ratio = 0.92–0.96), polished mesoscutum due to weak microsculpture with moderately dense punctures on centre of disc (i=0.5–1.5d), distinct but irregular mesepisternal punctures, weak longitudinal rugae on the metapostnotum not reaching rounded posterior margin, and brown metasomal terga with sparse tomentum and very obscure apical punctures. They are most similar to L. subversans and L. foveolatum . Female L. subversans have the mesoscutum dull due to microsculpture. Female L. foveolatum have a strongly convex supraclypeal area and very strong parapsidal lines.

Males of L. knereri and L. subversans can be distinguished from all other Canadian Dialictus by the very long and dense scopa-like hairs on S2–S3 and apicolateral portions of S4–S5. They may be distinguished by the apical impressed areas of the metasomal terga which are distinctly punctate in L. knereri but impunctate in L. subversans .

Description. FEMALE. Length 5.55–6.22 mm, head length 1.39–1.66 mm, head width 1.45–1.75 mm, forewing length 3.48–4.27 mm.

Colouration. Head and mesosoma golden green with blue reflections to blue with green reflections. Clypeus with apical half blackish brown and basal half and supraclypeal golden to bronze. Antenna dark brown, F5–F10 with ventral surface yellow-orange to brown. Tegula reddish brown. Wing membrane subhyaline, venation and pterostigma brownish yellow. Legs brown, medio- and distitarsi reddish brown. Metasoma dark brown, terga and sterna with apical margins reddish to yellowish brown.

Pubescence. Dull white. Moderately sparse. Head and mesosoma with moderately dense 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. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with dense, fine setae. T1 acarinarial fan complete dorsally. T2–T3 basolaterally and T4 entirely with sparse tomentum. T2 apicolateral and T3–T4 apical margins with weak fringes.

Surface sculpture. Face imbricate, punctation fine. Clypeus polished, basal margin imbricate, punctation moderately sparse (i=1–2.5d). Supraclypeal area with punctation moderately dense (i=1–1.5d). Lower paraocular area punctation dense (i≤1d). Antennocular area punctation moderately dense (i=1–1.5d). Upper paraocular area, frons and ocellocular area punctate-reticulate. Gena lineolate. Postgena polished, weakly lineolate. Mesoscutum polished; medial portion imbricate, punctation moderately dense between parapsidal lines (i=0.5–1.5d), dense laterad of parapsidal lines (i≤d), contiguous on anterolateral portion. Mesoscutellum similar to mesoscutum, submedial punctation sparse (i=1–4d). Axilla punctate. Metanotum imbricate. Preëpisternum weakly rugulose. Hypoepimeral area weakly imbricate-punctate. Mesepisternum polished, weakly rugulose with irregular punctation (i=0.5–1.5d). Metepisternum with dorsal fifth striate, ventral portion imbricate. Metapostnotum weakly rugoso-striate, posterior portion imbricate. Propodeum with dorsolateral slope ruguloso-imbricate, lateral and posterior surfaces imbricate-tessellate. Metasomal terga polished except apical impressed areas weakly coriarious, punctation fine on basal halves moderately dense (i=1–1.5d), moderately sparse on apical halves (i=1.5–2.5d).

Structure. Head wide (length/width ratio = 0.92–0.96). Eyes convergent below (UOD/LOD ratio = 1.14– 1.22). Clypeus 2/3 below suborbital line, apicolateral margins convergent. Antennal sockets close (IAD/OAD ratio <0.5). Gena narrower than eye. Tegula ovoid, slightly elongate. Inner metatibial spur pectinate with teeth. Metapostnotum moderately elongate (MMR ratio = 1.14–1.23), posterior margin elevated, rounded onto posterior surface. Propodeum with oblique carina weak, lateral carina weak, nearly reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 4.76 mm; head length 1.42 mm; head width 1.46 mm; forewing length 3.51 mm.

Colouration. Flagellum with ventral surface brownish yellow.

Pubescence. Face below eye emargination with dense woolly hairs and tomentum. Clypeus with moderately sparse tomentum, not obscuring surface. Lower paraocular area with moderately dense tomentum, obscuring surface. Gena with sparse tomentum. S2–S3 and S4–S5 apicolateral portions with very dense scopa-like hairs (1.5–2.5 OD). S5 apicomedial portion with dense appressed plumose hairs.

Surface sculpture. Clypeal punctation dense (i≤d). Mesosoma with strong punctures. Metapostnotum completely rugoso-striate. Propodeum with dorsolateral slope and lateral and posterior surfaces rugulosoimbricate. Metasomal terga strongly punctate throughout.

Structure. Head moderately wide (length/width ratio = 0.97). Eyes strongly convergent below (UOD/LOD ratio = 1.08). Antennal sockets distant (IAD/OAD> 1.1). Frontal line carinate, ending 2 OD below median ocellus. IOD less than OOD. Pedicel subequal to F1. F2 length 1.8X F1. F2–F10 moderately short (length/ width ratio = 1.23–1.45). Metapostnotum moderately elongate (MMR ratio = 1.14), posterior margin sharply angled onto posterior surface.

Terminalia . S7 with median lobe narrowly clavate, sides subparallel, apex rounded ( Fig. 131D ). S8 with apicomedial margin weakly convex ( Fig. 131D ). Genitalia as in Fig. 131D–F . Gonobase with ventral arms narrowly separated. Gonostylus small, dorsal setae elongate. Retrorse lobes narrow, weakly attenuated apically.

Range. Alberta, British Columbia south to California , Colorado ( Fig. 129 ).

Allotype. 1♂ Mariposa Co., Merced Lk. Tr., 1.9 mi EbyN Bunnell Pt., 11S N4187049 E285074, 2141 m, 12.viii.2004 ( R. Maddox & E. Stephens); [ BBSL]

Paratypes. CANADA: ALBERTA: 1♀ Waterton Lakes N.P., Cardston Ent., 3–17.viii.2000 ; 1♀ Waterton Lakes N.P., Cardston Ent. , 6–20.vii.2000; [ BDUC] ; BRITISH COLUMBIA: 1♀ topotypical 14.v.2003 (C. Ratti) ; 1♀ Cowichan Lake Forestry Station, Ministry of Forests, Mesachie Lake , N48°49´07.9´´ W124°08´05.1´´, 27.iv.2005 (E. Elle) ; 1♀ Cowichan Lake Forestry Station, Ministry of Forests, Mesachie Lake , N48°49´07.9´´ W124°08´05.1´´, 11.v.2005 (E. Elle) ; 1♀ Cowichan Lake Forestry Station, Ministry of Forests, Mesachie Lake , N48°49´07.9´´ W124°08´05.1´´, 28.vi.2005 (E. Elle) ; 1♀ Highrock (Cairn) Park , Victoria , Dist. of Esquimalt , N48°26´08.8´´ W123°24´24.9´´, 1.v.2005 (E. Elle) ; 1♀ Konukson Park, Victoria, Dist. of Saanich , N48°47´25.8´´ W123°16´25.4´´, 18.iv.2005 (E. Elle) ; 1♀ Konukson Park, Victoria, Dist. of Saanich , N48°47´25.8´´ W123°16´25.4´´, 1.v.2005 (E. Elle) ; 1♀ Surrey , N49°05´54´´ W122°47´31´´ 7.v.2003 (C. Ratti) ; 1♀ Sooke Potholes P.P., 6 km N Sooke, N48°25´44.3´´ W123°42´40.9´´, 30.v.2005 (E. Elle) ; 1♀ Stoltz Meadows , 15 km E Lake Cowichan, N48°46´54´´ W123°3´06.9´´, 11.v.2005 (E. Elle) ; 1♀ Surrey , N49°05´54´´ W122°47´31´´ 14.v.2003 (C. Ratti) ; 1♀ Surrey , N49°05´54´´ W122°47´31´´ 26.v.2003 (C. Ratti) ; 1♀ Westham Island , N49°05´18´´ W123°09´50´´ 23.iv.2003 (C. Ratti); [ PCYU] ; 1♀ Blind Bay, near Sorrento , vi.1987 (C.A. Elsey); [ CNC] ; USA: CALIFORNIA : 1♀ Mariposa Co., Merced Lk. Tr., 1.9 mi EbyN Bunnell Pt. , 11S N4180202 E285717, 2141 m, 3.vi.2005 (H. Briggs & E. Stephens) ; 1♀ 2 mi W Andrews Peak , 11S N4213840 E261572, 2394 m, 2.vii.2005 (E. Stephens & J. Gibbs) ; 2♀ Tuolumne Co., Hodgon Meadow , 11S N4187049 E248074, 1414 m, 5.vii.2005 (L. Fuerst & H. Briggs) ; 1♀ Tuolumne Co., Hodgon Meadow , 11S N4187049 E248074, 1414 m, 3.viii.2005 (H. Briggs & L. Fuerst); [ BBSL] ; COLORADO: 3♀ Jackson Co., N40.6017 W106.0726, 11–12.v.2004 (S.W. Droege) ; 8♀ Larimer Co., N40.6833 W105.3975, 11–12.v.2004 (S.W. Droege) ; IDAHO: 1♀ Fremont Co., N44.39329 W111.38278, 2032 m, 23.vi.2007 (Gibbs & Sheffield) ; 1♀ Valley Co., nr Smiths Ferry, Hwy 55, N44.29777 W116.08869, 28.v.2007 (Gibbs & Sheffield) ; OREGON: 1♀ Douglas Co., N43.2143 W123.3768, 13.viii.2005 (E. Soderhlom); [ PCYU]; WASH- INGTON: 1♀ Okanagan Co., 1 mi E Muckamuck Hill , 11U N5386867 E296155, 4.vii.2004 (J. Wilson & L. Wilson); [ BBSL] .

Etymology. The specific epithet is dedicated to Gerd Knerer for his studies of halictine bees and descriptions of Canadian Dialictus .

Floral records. CAMPANULACEAE : Campanula rotundifolia .

Comments. Common. This species seems to exhibit some phylogeographic structure in the DNA barcode sequences. Five possible haplotypes were found, one each from California / Oregon, Idaho and Colorado, and two from Southern British Columbia. The total sequence variation observed for DNA barcodes from specimens taken from throughout the range was less than 1.2%.

Figures

FIGURE 129. Distribution of Lasioglossum incompletum (medium grey), L. knereri (dark grey), and L. laevissimum (light grey).

FIGURE 130. Lasioglossum knereri new species. Female (A) lateral habitus; (B) dorsal habitus; (C) face. Scale bars, A– C = 1 mm.

FIGURE 131. Lasioglossum knereri new species. Male (A) lateral habitus; (B) dorsal habitus; (C) face; (D) ventral view of genital capsule, S7, S8; (E) dorsal view of genital capsule; (F) apical view of genital capsule. Scale bars, A–C = 1 mm, F = 0.5 mm.