Lasioglossum (Dialictus) planatum (Lovell)

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 259-261

Lasioglossum (Dialictus) planatum (Lovell)

( Figure 183A–D )

Halictus planatus Lovell, 1905b: 300 . ♀ Lectotype. ♀ USA, Maine, Waldoboro , (J.H. Lovell); [NMNH: 71572] by T. B. Mitchell. Examined.

Taxonomy. Wolf & Ascher, 2009: Lasioglossum (Dialictus) planatum , p. 144 (faunal list).

Diagnosis. See diagnosis for L taylorae and L. ephialtum .

Redescription. FEMALE. Length 5.37–6.10 mm; head length 1.42–1.56 mm; head width 1.46–1.58 mm; forewing length 3.84–4.15 mm.

Colouration. Head and mesosoma bluish green with golden reflections. Clypeus with apical margin blackish brown. Supraclypeal area golden. Antenna dark brown, F6–F10 with ventral surface yellow-orange to brown. Tegula reddish to yellowish brown. Wing membrane subhyaline, venation and pterostigma pale yellowish brown. Legs brown, medio- and distitarsi reddish brown. Metasoma dark brown, terga and sterna with apical margins reddish brown.

Pubescence. Dull white. 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 subappressed hairs. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with sparse, fine setae. T1 acarinarial fan with dorsal opening equal to lateral hair patches. T2–T3 basolateral area with sparse tomentum. T4 with tomentum sparsely scattered across disc.

Surface sculpture. Face imbricate. Clypeus polished, weakly imbricate, punctation strong (i=1–3d). Supraclypeal area polished or weakly imbricate medially, punctation moderately sparse (i=1–2d). Lower paraocular area punctation dense (i≤1d). Antennocular area punctation moderately sparse (i=1–2.5d). Upper paraocular area and frons reticulate. Ocellocular area irregularly punctate. Gena lineolate. Postgena polished. Mesoscutum tessellate anteromedially, remainder imbricate to moderately polished, punctation fine, sparse between parapsidal lines (i=1–2.5d), close laterad of parapsidal lines (i≤d), contiguous on anterolateral portion. Mesoscutellum polished, submedial punctation sparse (i=2–4d). Axilla punctate. Metanotum imbricate. Preëpisternum rugulose. Hypoepimeral area weakly ruguloso-imbricate. Mesepisternum rugulose above, weakly ruguloso-imbricate below, sometimes with obscure punctation throughout. Metepisternum with dorsal half striate, ventral half imbricate. Metapostnotum incompletely striate, submedial zone weakly sculptured or imbricate. Propodeum with dorsolateral slope rugulose, lateral surface tessellate, posterior surface imbricate. Metasomal terga polished, weakly coriarious, punctation on basal halves (i=1–2d), apical half impunctate (except along premarginal line).

Structure. Head moderately wide (length/width ratio = 0.97–0.98). Eyes convergent below (UOD/LOD ratio = 1.24–1.29). Clypeus projecting 2/3 below suborbital line, apicolateral margins convergent. Antennal sockets close (IAD/ AOD ratio <0.5). OOD less than IOD. Gena narrower than eye. Inner metatibial spur pectinate with teeth. Metapostnotum moderately elongate (MMR ratio = 1.23). Propodeum with oblique carina virtually absent, lateral carina not reaching dorsal margin.

MALE. Unknown.

Range. Newfoundland, New Brunswick west to British Columbia and Northwest Territories, south to Maine ( Fig. 182 ).

Additional material examined. CANADA: ALBERTA: 1♀ Kananaskis, U of C field station, 1391 m, 19.vi.2007 (Gibbs & Sheffield) ; BRITISH COLUMBIA: 1♀ 10.vii.2002 ; 1♀ 11.vii.2002; NEW BRUNS- WICK: 4 ♀ Kent Co., St. Ignace , N46.707 W071.054, 32. vii.2005 (M. Gravel) ; NEWFOUNDLAND: 1♀ St. Davids , N.45’50.557’’ W66’ 54.682, 17.vi.2004 (Goulet, Boudreault & Badiss) ; 1♀ Fort Providence , N61.2204 W117.6051, 21.vi.2005 (C. Sheffield & A. Gunn) ; NORTHWEST TERRITORIES: 1♀ Hay River , banks, N60°33´W116°08´, 7.viii.2004 (A. Gunn) ; NOVA SCOTIA: 3♀ Kings Co., Up. Canard , N45.135 W064.489, 29.v.2002 (C. Sheffield); [ PCYU] ; QUEBEC: 1♀ St. Anne’s , 17.v.1931; [ BMNH] ; 1♀ W of Nor mandin, N48°48´13.1´´ W72°36´28.6´´, 170 m, 8.vi.2009 (M. Chagnon) ; 1♀ W of Normandin , N48°51´15.1´´ W72°37´01.5´´, 185 m, 25.vi.2009 (M. Chagnon) ; 2♀♀ W of Normandin , N48°51´25.3´´ W72°36´36.6´´, 186 m, 8.vi.2009 (M. Chagnon); [ PCYU] ; USA: WISCONSIN: 1♀ Waukesha Co., Scuppernong Prairie , N42.89548 W088.50513, 2.vii.2006 (A. Wolf); [ PCYU] .

Floral records. See floral records for L. oblongum . ONAGRACEAE : Chamerion angustifolium .

Comments. Uncommon. This species has long been treated as a synonym of L. oblongum ( Lovell 1908) . For discussion see the Comments section for that species. This is a member of the L. viridatum species-group.

Figures

FIGURE 182. Distribution of Lasioglossum pilosum (medium grey), L. floridanum (dark grey), and L. planatum (light grey).

FIGURE 183. Lasioglossum planatum (Lovell). Female (A) lateral habitus; (B) dorsal habitus; (C) face; (D) metapostnotum. Scale bars, A–C = 1 mm.