Lasioglossum (Dialictus) vierecki (Crawford)

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 346-351

Lasioglossum (Dialictus) vierecki (Crawford)

( Figures 233A–D , 234A–E )

Halictus vierecki Crawford, 1904: 97 . ♀. Holotype. ♀ USA, New Jersey, Clementon , 6.vi.1830 [ANSP: 10206]. Examined. [specimen missing head]

Taxonomy. Graenicher, 1910: Halictus vierecki ♂, p. 158 (description); Viereck, 1916: Halictus (Chloralictus) vierecki , p. 707; Michener, 1951: Lasioglossum (Chloralictus) vierecki , p. 1118 (catalogue); Mitchell, 1960: Dialictus vierecki ♂, p. 429 (redescription); Krombein, 1967: Lasioglossum (Dialictus) vierecki , p. 466 (catalogue); Dialictus vierecki , p. 1973 (catalogue); Moure & Hurd, 1987: Dialictus vierecki , p. 139 (catalogue).

Diagnosis. Females of L. vierecki can be recognised by the diagnostic combination of a pale brownish yellow metasoma, very dense yellowish tomentum on the head, mesosoma ( Fig. 233D ) and metasomal terga, brownish yellow apical half of the clypeus, and extensively brownish yellow legs.

Males of L. vierecki can be recognised by the diagnostic combination of a small size (2.9–4.9 mm), dense mesoscutal punctures (i<d), distinct mesepisternal punctures, and reddish brown metasomal terga with basal portions of T2–T3 distinctly impressed.

For comparisons to similar species see the diagnosis for L. pictum .

Redescription. FEMALE. Length 4.21–5.06 mm; head length 1.20–1.27 mm; head width 1.12–1.26 mm; forewing length 2.75–3.17 mm.

Colouration. Head and mesosoma golden green. Labrum yellowish brown. Mandible brownish yellow. Clypeus with apical half brownish yellow. Antenna dark brown, F4–F10 with ventral surface brownish yellow. Tegula, wing venation (except vein C reddish brown), and pterostigma pale brownish yellow. Legs primarily brownish yellow, coxae usually brown, trochanters and femora sometimes brown or infused with brown, tibiae infused with brown. Metasoma pale brownish yellow.

Pubescence. Very abundant. Yellowish. Head and mesosoma with dense woolly hairs (1–1.5 OD), longest on genal beard, metanotum and mesopleuron (1.5–2.5 OD). Head and mesosoma covered with tomentum (except postgena and dorsal surface of propodeum). Metanotum, hypoepimeral area and metepisternum with dense tomentum obscuring surface. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (1.5–2 OD). Metasomal terga with moderately dense, fine setae. T1 acarinarial fan complete dorsally. T1 dorsolaterally, T2 baso- and apicolaterally, and T3–T4 entirely with dense tomentum obscuring surface. T2 apicolateral and T3–T4 apical margins with moderately dense fringes.

Surface sculpture. Face weakly imbricate, punctation moderately strong. Clypeus polished, basal margin weakly imbricate, punctation moderately sparse (i=1–2d). Supraclypeal area with punctation moderately dense (i=1–1.5d). Lower paraocular and antennocular areas with with punctation dense (i≤d). Upper paraocular area, frons and ocellocular area punctate-reticulate. Gena and postgena strigate. Mesoscutum and mesoscutellum punctation dense throughout (i<d). Axilla imbricate. Metanotum ruguloso-imbricate. Preëpisternum rugulose. Hypoepimeral area rugulose-reticulate. Mesepisternum dorsal portion rugulose, ventral portion reticulate-imbricate. Metepisternum dorsal half rugoso-striate, ventral half imbricate. Metapostnotum weakly, ruguloso-striate, posterior margin tessellate. Propodeum dorsolateral slope, lateral and posterior surfaces ruguloso-imbricate. Metasomal terga polished, punctation dense throughout (i=1–1.5d).

Structure. Head round to moderately elongate (length/width ratio = 0.98–1.02). Eyes convergent below (UOD/LOD ratio = 1.26–1.29). Clypeus 2/3 below suborbital tangent, apicolateral margins convergent. Antennal sockets close (IAD/OAD <0.5). Frontal line carinate, ending 3 OD below median ocellus. Gena narrower than eye. Inner metatibial spur pectinate with 2–4 teeth. Metapostnotum delimited laterally by weak carina. Metapostnotum truncate (MMR ratio = 1.44–1.69), posterior margin weakly angled onto posterior surface. Propodeum with oblique carina weak, lateral carina short reaching less than halfway to dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 2.87– 4.85 mm; head length 0.94–1.30 mm; head width 0.90–1.24 mm; forewing length 2.14–3.05 mm.

Colouration. Head and mesosoma with less brownish yellow areas. Labrum and mandible yellow. Flagellum ventral surface. Tegula reddish brown. Wing membrane subhyaline, venation and pterostigma brownish yellow. Tibial bases and apices and tarsi yellow to brownish yellow. Metasomal terga golden brown with reddish reflections.

Pubescence. Clypeus, supraclypeal area, and gena with sparse tomentum partially obscuring surface. Lower paraocular area with dense tomentum obscuring surface. Preëpisternum, mesepisternum, metepisternum and lateral surface of propodeum with tomentum partially obscuring surface, surface of metepisternum completely obscured. T1 with subappressed T1 acarinarial fan. T1–T3 with basolateral tomentum. T4–T5 with scattered tomentum across disc partially obscuring surface. S2–S4 apical halves with moderately dense plumose hairs (1.5–2 OD). S5 apical half with longer posteriorly directed hairs (2 OD).

Surface sculpture. Gena and postgena polished, faintly lineolate. Metanotum punctate. Mesepisternum with dense, contiguous punctures. Propodeum dorsolateral slope, lateral and posterior surfaces weakly reticulate-rugulose.

Structure. Head elongate (length/width ratio = 1.03–1.07). Eyes convergent below (UOD/LOD ratio = 1.50–1.57). Clypeus 1/2 below suborbital tangent, apicolateral margins weakly convergent. Antennal sockets moderately distant (IAD/OAD> 0.8). Frontal line carinate, ending 2 OD below median ocellus. IOD subequal to OOD. Pedicel subequal to F1. F2 length 1.6–1.8X F1. F2–F10 (length/width ratio = 1.44–1.63). Metapostnotum truncate (MMR ratio = 1.38–1.57), posterior margin weakly angled onto posterior surface. T2–T3 impressed basally.

Terminalia . S7 with median lobe elongate, narrowly clavate, apex rounded ( Fig. 234D ). S8 with apicomedial margin strongly convex ( Fig. 234D ). Genitalia as in Fig. 234D–E . Gonobase with ventral rim narrowly separated. Gonostylus large, covered with elongate setae. Retrorse lobes elongate, attenuated apically, covered with long setae. Penis valve strongly attenuated apically.

Range. Manitoba and Ontario south to Texas and Florida ( Fig. 235 ).

Additional material examined. CANADA: MANITOBA: 1♂ YellowQuill Mxd. Grass Prairie Preserve, nr. Treesbank , N49°41´28´´ W099°34´29´´, 22.viii.2005 (A.M. Patenaude) ; ONTARIO: 1♀ Manester Tract, St. Williams , N43°43´W080°26´, 12.viii–1.ix.1992 (P.J. Carson) ; 1♀ Manester Tract, St. Williams , N43°43´W080°26´, 18–30.xii.1992 (P.J. Carson) ; 1♂ Manester Tract, St. Williams , N43°43´W080°26´, 26.viii– 17.ix.1993 (L. Packer) ; 5♀♀ 2♂ Manester Tract, St. Williams , N43°43´W080°26´, 2–8.vi.1994 (P.J. Carson) ; 1♀ 1♂ Manester Tract, St. Williams , N43°43´W080°26´, 22.vii.1995 (L. Packer) ; 1♀ Manester Tract, St. Williams , N43°43´W080°26´, 23.vii.1996 (P.J. Carson) ; 5♀♀ Norfolk , N42°39.088 W080°34.275´, 11.viii.2007 (A. Taylor) ; 1♀ Norfolk Co., Pterophylla Plant Nursery , N42°38.404´W080°34.379´, mt, 23.viii–3.xi.2006 (P.J Carson) ; 2♀♀ Norfolk Co., St. Williams Forestery Stn. , N42°41.6´W080°27.4´, 12.vi.1998 (H. Douglas) ; 1♀ RM Haldimane-Norfolk, Delhi Prairie NH420441, 28.v.1998 (H. Douglas) ; 2♀♀ RM Haldimane-Norfolk, Manestar Sav. NT443268, 29.v.1998 (H. Douglas) ; 1♀ Turkey Point P.P., 11.viii.1984 (L. Packer); [ PCYU] ; QUEBEC: 2♀♀ Eardley, nr Jct. Hwy 148 & Eardely-Masham Rd. , 15– 22.v.1991 ( BRC Hym Team); [ CNC] ; USA: INDIANA: 1♀ Jasper Co., Nipsco , 27.iv.2003 ( R. P. Jean) ; MARYLAND: 11♂ Anne Arundel Co., N38.7847 W076.7002, 15.ix.2007 (S.W. Droege) ; 1♀ Anne Arundel Co., N38.9282 W076.6683, 27.vii.2004 (A. Lohr) ; 1♀ Pr. George’s Co., N38.9764 W076.7491, 20.viii.2004 (S. Kolski) ; MASSACHUSETTS: 1♀ Middlesex Co., sandpit, 1.1 mi E of Pepperell , 20.v.2006 (M.F. Veit) ; 1♀ Middlesex Co., sandpit, 1.1 mi SE of Pepperell , 6.vi.2006 (M.F. Veit) ; MICHIGAN: 5♂♂ Allegan Co., N42.5538 W086.0437, 28.viii.2003 (S.W. Droege) ; MINNESOTA: 1♀ Sher Co., Zimmerman, Sherburne NWR , 10.vii.2001 (S. Droege); [ PCYU] ; NEW JERSEY: 4♀ paratypes, topotypical ; 1♀ paratype, Riverton , 17.iv.1898; [ ANSP] ; 1♀ paratype topotypical; [ NMNH] ; NEW YORK: 1♀ Albany Co., Albany Pinebush , 1.vii.2004 (J.S. Ascher); [ AMNH] ; 1♀ Albany Co., Colonie , 20.viii.1969 (G. & K. Eickwort); [ CUIC] ; 1♀ 5♂♂ Suffolk Co., 6.ix.2005 (S.W. Droege) ; NORTH CAROLINA: 1♀ Moore Co., N35.2844 W079.314, 19.v.2006 (S.W. Droege) ; RHODE ISLAND: 1♂ Newport Co., N41.4969 W071.3678, 22.vii.2005 (P. Ostenton) ; SOUTH CAROLINA: 1♀ Chesterfield Co., N34.5036 W080.24485, 18–19.v.2006 (S.W. Droege) ; 1♀ Chesterfield Co., N34.5996 W080.21432, 18–19.v.2006 (S.W. Droege) ; TEXAS: 1♀ Bastrop Co., Stengl Biological Station , 6 mi N of Smithville, 12.v.2000 (J. Abbott & R. Caesar); [ PCYU] .

Floral records. ASTERACEAE : Aster , Euthamia graminifolia , Helianthus , Rudbeckia hirta , BRASSI- CACEAE: Lepidium , CAMPANULACEAE : Specularia , CISTACEAE : Helianthemum canadense , FABACEAE : Melilotus , HYDRANGEACEAE : Hydrangea , LAMIACEAE : Monarda punctata , RHAMNA- CEAE: Ceanothus americanus , ROSACEAE : Rubus flagellaris .

Biology. Danforth 1999: (phylogeny); Danforth & Ji 2001: (phylogeny); Danforth et al. 2003: (phylogeny).

Comments. Common. This species seems to have a preference for sandy soils and can be collected in abundance in certain areas.

Figures

FIGURE 233. Lasioglossum vierecki (Crawford). Female (A) lateral habitus; (B) dorsal habitus; (C) face; (D) mesoscutum. Scale bars, A–C = 1 mm.

FIGURE 234. Lasioglossum vierecki (Crawford). Male (A) lateral habitus; (B) dorsal habitus; (C) face; (D) ventral view of genital capsule, S7, S8; (E) dorsal view of genital capsule. Scale bars, A–C = 1 mm, E = 0.5 mm.

FIGURE 235. Distribution of Lasioglossum vierecki (light grey) and L. viridatum (dark grey).