Lasioglossum (Dialictus) perpunctatum (Ellis)

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 244-249

Lasioglossum (Dialictus) perpunctatum (Ellis)

( Figures 175A–C , 176A–G )

Halictus perpunctatus Ellis, 1913: 210 . ♀.

Holotype. ♀ USA, Colorado, Boulder , 20.iv., on Claytonia, (T.D.A. Cockerell) , [ CAS: 15617]. Examined.

Halictus brycinci Crawford, 1932: 70 . ♀.

Holotype. ♀ USA, North Carolina, Bryson City , 14.iv.1923, (J.C. Crawford), [ NMNH: 40304]. Examined. Dialictus highlandicus Mitchell, 1960: 398 . ♀. [new synonymy]

Holotype. ♀ USA, North Carolina, Highlands , 22.vii.1958 [ NCSU]. Examined.

Dialictus junaluskensis Mitchell, 1960: 437 . ♂. [new synonymy]

Holotype. ♂ USA, North Carolina, Lake Junaluska , 9.vi.1955, (H. V. Weems, Jr.), [ FSCA]. Examined.

Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) perpunctatum , p. 1116 (catalogue); Mitchell, 1960: Dialictus perpunctatus ♂, p. 411, H. brysinci (lapsus calami), p. 411 (redescription, synonymy); Krombein, 1967: Lasioglossum (Dialictus) highlandicum , p. 464, L. (D.) junaluskense , p. 464, L. (D.) perpunctatum , p. 465 (catalogue); Hurd, 1979: Dialictus highlandicus , p. 1966, D. junaluskensis , p. 1967, D. perpunctatus , p. 1970 (catalogue); Moure & Hurd, 1987: Dialictus highlandicus , p. 104, D. junaluskensis , p. 109, D. perpunctatus , p. 121 (catalogue).

Diagnosis. Females of L. perpunctatum can be recognised by the diagnostic combination of a wide head (length/width ratio = 0.95–0.96), dense mesoscutal punctation (i<d), punctate mesepisternum, completely rugoso-striate metapostnotum, weak posterior angle of the tegula, brown metasomal terga sometimes with obscure greenish reflections, complete T1 acarinarial fan and abundant appressed tomentum of T3–T4. They are similar to L. sheffieldi and L. yukonae . Female L. sheffieldi have a relatively elongate head (length/width ratio = 1.00–1.01) and distinctly separated punctures on the median portion of the mesoscutum. Female L. yukonae have a moderately wide to round head (length/width ratio = 0.96–1.00) and imbricate mesepisternum with very obscure punctures.

Males of L. perpunctatum can be recognised by their moderately elongate heads (length/width ratio = 1.00–1.03), moderately elongate flagellomeres (length/width ratio = 1.43–1.58), coarse mesoscutal punctures that are moderately sparse on the central disc (i=1–2d), weak posterior angle of the tegula, distinct mesepisternal punctures, longitudinal rugae on the metapostnotum reaching the posterior margin, and strong punctures on the metasomal terga that are sparser on the apical impressed areas. They are similar to L. sheffieldi which has a more elongate head (length/width ratio = 1.06–1.08).

Redescription. FEMALE. Length 5.25–6.25 mm; head length 1.37–1.58 mm; head width 1.44–1.66 mm; forewing length 4.21–4.45 mm.

Colouration. Head and mesosoma pale green to bluish green. Clypeus with apical half blackish brown and basal half, and supraclypeal area bronze. Antenna dark brown, flagellum with ventral surface reddish brown. Tegula reddish brown. Wing membrane subhyaline, venation and pterostigma amber. Legs brown, medio- and distitarsi reddish brown. Metasomal terga usually faintly metallic green, sterna brown, apical margins translucent brownish yellow.

Pubescence. Dull white. Moderately dense. 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 subappressed tomentum, not obscuring surface. 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 complete. T2 basolaterally and T3–T5 entirely with dense tomentum largely obscuring surface. T2 apicolateral and T3–T4 apical margins with weak fringes.

Surface sculpture. Face imbricate, punctation moderately strong. Clypeus with apical half polished, punctation sparse (i=1–3d). Supraclypeal area with punctation sparse (i=1–2.5d). Lower paraocular area punctation dense (i≤d). Antennocular area punctation moderately dense (i=1–1.5d). Upper paraocular area, frons and ocellocular area punctate-reticulate. Gena faintly lineolate. Postgena polished. Mesoscutum weakly imbricate, polished submedially, punctation contiguous between parapsidal lines (i<d), reticulate-punctate laterad of parapsidal lines and on anterolateral portions. Mesoscutellum polished, submedial punctation moderately sparse (i=1–2d). Axilla punctate. Metanotum imbricate. Preëpisternum rugulose. Hypoepimeral area imbricate-punctulate. Mesepisternum ruguloso-punctate (i≤d), more polished below. Metepisternum with dorsal half rugoso-striate, ventral half imbricate. Metapostnotum with complete, irregular rugae, posterior margin rounded and raised. Propodeum with dorsolateral slope and lateral and posterior surfaces imbricate. Metasomal terga polished except apical and basal margins weakly coriarious, punctation on basal halves moderately sparse (i=1–2d), sparse on apical halves (i=1–3d).

Structure. Head wide (length/width ratio = 0.95–0.96). Eyes convergent below (UOD/LOD ratio = 1.16– 1.19). Clypeus 1/2–2/3 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. Tegula ovoid, posterior margin with very small angled projection. Inner metatibial spur pectinate with 3–6 teeth. Metapostnotum elongate (MMR ratio = 1.07–1.15), posterior margin rounded onto posterior surface. Propodeum with oblique carina weak, lateral carina weak, not reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 5.25– 5.67 mm; head length 1.49–1.56 mm; head width 1.49–1.56 mm; forewing length 4.03–4.09 mm.

Colouration. Head and mesosoma more bluish. Metasomal terga brown.

Pubescence. Face below eye emargination with subappressed tomentum obscuring surface on lower paraocular area, sparse elsewhere. Metasomal terga without appressed tomentum.

Surface sculpture. Integument more polished. Postgena imbricate. Mesoscutal punctation moderately sparse between parapsidal lines (i=1–2d). Preëpisternum rugoso-reticulate. Hypoepimeral area polished, punctate (i=d). Mesepisternum polished, punctation distinct (i≤d). Propodeum lateral and posterior surface rugulose.

Structure. Head moderately elongate (length/width ratio = 1.00–1.03). Eyes convergent below (UOD/ LOD ratio = 1.39–1.41). Clypeus 2/3 below suborbital tangent, apicolateral margins convergent. Antennal sockets distant (IAD/OAD> 1.0). Frontal line carinate, ending 2 OD below median ocellus. IOD subequal to OOD. Pedicel shorter than F1. F2 length 1.7–1.8X F1. F2–F10 moderately elongate (length/width ratio = 1.43–1.58). Metapostnotum elongate (MMR ratio = 1.09–1.23), posterior margin weakly angled onto posterior surface.

Terminalia . S7 with median lobe elongate, clavate, apex rounded ( Fig. 176F ). S8 with apicomedial margin strongly convex ( Fig. 176F ). Genitalia as in Fig. 176D–E, G . Gonobase with ventral arms narrowly separate. Gonostylus small. Retrorse lobe elongate, weakly attenuated apically.

Range. Nova Scotia west to Manitoba and Colorado, south to North Carolina ( Fig. 177 ).

Additional material examined. CANADA: ALBERTA: 1♀ Writing-On-Stone, 14.vi.1984 ( T. Spanton) ; 1♀ Writing-On-Stone, sand pit, 15.vi.1982 (D.B. McCorquodale); [ PMAE] ; MANITOBA: 1♀ YellowQuill Mxd., Grass Prairie Preserve, near Treesbank , N49°40´51´´ W099°33´15´´, 20.vi.2005 (A.M. Patenaude) ; 1♀ YellowQuill Mxd., Grass Prairie Preserve, near Treesbank , N49°40´51´´ W099°33´16´´, 15.vi.2005 (A.M. Patenaude) ; 1♀ YellowQuill Mxd., Grass Prairie Preserve, near Treesbank , N49°41´28´´ W099°34´29´´, 1.vi.2005 (A.M. Patenaude) ; 1♀ YellowQuill Mxd., Grass Prairie Preserve, near Treesbank , N49°41´28´´ W099°34´29´´, 6.vi.2005 (A.M. Patenaude) ; 1♀ 1♂ YellowQuill Mxd., Grass Prairie Preserve, near Treesbank , N49°41´28´´ W099°34´29´´, 20.vii.2005 (A.M. Patenaude) ; 1♀ YellowQuill Mxd., Grass Prairie Preserve, near Treesbank , N49°41´28´´ W099°34´29´´, 11.ix.2005 (A.M. Patenaude) ; NOVA SCOTIA: 1♀ Kings Co., Avonport , N45.1189 W064.2634, 3.vii.2002 (C. Sheffield) ; 7♀ Kings Co., Avonport , N45.1198 W064.273, 13.vi.2002 (C. Sheffield) ; ONTARIO: 1♂ Cornwall , 1.ix.1961 (G. Knerer) ; 1♀ Forks of Credit , 27.v.1969 (P. MacKay) ; SASKATCHEWAN: 1♀ N of Rocanville, Qu’Appelle R ., N50.5084 W101.7516, 454 m, 2.vi.2007 (Goulet, Boudreault & Fernandez); [ PCYU] ; USA: COLORADO: 2♀ Larimer Co., N40.6833 W105.3975, 11–12.v.2004 (S.W. Droege) ; INDIANA: 1♀ Jasper Co., Nipsco , 1.vii.2003 ( R. P. Jean) ; 1♀ Newton Co., Conrad , 24.vi.2002 ( R. P. Jean); [ PCYU] ; MINNESOTA: 1♀ Clay Co., 3 mi E, 2 mi S Felton, Felton Prairie , N47°03´59.2´´ W096°26´00.1´´, 21.vii.2006 ( R. L. Andres) ; NEW YORK: 1♀ Schuyler Co., Reisinger, Watkins Gin , 13.v.2009 (J. R. Litman) ; 1♀ Tompkins Co., Cornell Orchards, Lansing , 6.v.2008 (S.C. Cardinal); [ CUIC] ; NORTH CAROLINA: 4♀ Swain Co., N35.5917 W083.0602, 2.iv.2002 (H.W. Ikerd); [ PCYU] ; WISCONSIN: 2♀ Dane Co., Westport Drumlin , 11.vii.1996 ( R. A. Henderson); [ IRCW] .

Floral records. ANACARDIACEAE : Rhus , ASTERACEAE : Antennaria , Anthemis , Chrysanthemum , Cirsium , Erigeron , Lasthenia californica , Rudbeckia , Solidago , Taraxacum Taraxacum , BRASSICACEAE : Barbarea , Brassica , Capsella bursa-pastoris , Raphanus , EUPHORBIACEAE : Euphorbia , FABACEAE : Melilotus , POLYGONACEAE : Fagopyrum , PORTULACACEAE : Claytonia rosea , ROSACEAE : Crataegus , Fragaria virginiana , Malus , Potentilla canadensis , Rubus , SALICACEAE : Salix , SOLANACEAE : Physalis .

Comments. Common. This species has been reported as far west as California . Several similar species occur in the western United States and these records could be mistaken.

The holotype specimen of D. highlandicus has only obscure punctation on the mesepisternum. The visibility of punctures on the mesepisternum forms a gradient from obscure to distinct in L. perpunctatum . In all other respects the holotype of D. highlandicus matches a typical L. perpunctatum .

Figures

FIGURE 175. Lasioglossum perpunctatum (Ellis). Female (A) lateral habitus; (B) dorsal habitus; (C) face. Scale bars, A–C = 1 mm.

FIGURE 176. Lasioglossum perpunctatum (Ellis). Male (A) lateral habitus; (B) dorsal habitus; (C) face; (D) ventral view of genital capsule; (E) dorsal view of genital capsule; (F) S7, S8; (G) oblique view of gonostylus, retrorse lobe. Scale bars, A–C = 1 mm, G = 0.5 mm.

FIGURE 177. Distribution of Lasioglossum perpunctatum (light grey) and L. pictum (dark grey).