Lasioglossum ( Dialictus ) sheffieldi Gibbs

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 176-177

Lasioglossum ( Dialictus) sheffieldi Gibbs

Lasioglossum ( Dialictus) sheffieldi Gibbs, 2010b: 302 . Ƥ3.

Holotype. Ƥ CANADA, Nova Scotia, Kings Co., Avonport, N45.1198 W064.2730, 18.vii.2002 (C. Sheffield); [ PCYU].

Diagnosis. Female L. sheffieldi can be recognised by the following diagnostic combination: head moderately long (length/width ratio = 1.00–1.01); mesoscutum tessellate, punctures dense except medially ( Fig. 13 B); mesepisternum shining, irregularly punctate; metapostnotum with strongly anastomosing rugae; T1 acarinarial fan complete dorsally; metasomal terga polished with faint metallic reflections; and T3–T4 with moderately dense tomentum. They are similar to L. perpunctatum , which has a wider head (length/width ratio = 0.95–0.96) and dense mesoscutal punctures medially ( Fig. 13 A).

Male L. sheffieldi can be recognised by the following diagnostic combination: head long (length/width ratio = 1.06– 1.08), dense facial tomentum limited to lower paraocular area, flagellomeres relatively short (length/width ratio = 1.20– 1.62), mesoscutal punctures sparse between parapsidal lines (i=1–3d), mesepisternum with distinct punctures, tegula with weak posterior angle, and apical impressed areas of metasomal terga pale translucent yellow, distinctly punctate. They are similar to L. perpunctatum , which has a wider head (length/width ratio = 1.00–1.03).

Range. Coastal dunes of Nova Scotia, southern Newfoundland, west to Quebec. Disjunct individuals from western coast of Lake Michigan and Manitoba dunes. USA: WI. CANADA: MB, NB, NF, NS, PQ.

DNA Barcode. Available. Multiple sequences.

Comments. Locally common. Lasioglossum sheffieldi is a sand dune specialist.

Figures

FIGURE 13. Mesoscutal punctation (A) completely dense, (B) sparse medially (indicated by arrow). (From Gibbs 2010 b).