Lasioglossum (Dialictus) viridatum (Lovell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 207-208

Lasioglossum (Dialictus) viridatum (Lovell)

Halictus viridatus Lovell, 1905b: 300 . Ƥ 3.

Lectotype. Ƥ USA, Maine, Waldoboro, vi, [NMNH: 71574] designated herein. Examined. Dialictus lepidus Mitchell, 1960: 438 . 3.

Holotype. 3 USA, Michigan, Keweenaw Co., 27.viii. [year obscured] (R.R. Dreisbach); [ NCSU]. Examined.

Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) viridatum , p. 1118 (catalogue); Mitchell, 1960: Dialictus viridatus Ƥ, p. 430 (redescription); Mitchell, 1962: Dialictus viridatus , p. 547 (synonymy); Krombein, 1967: Lasioglossum (Dialictus) viridatum , p. 466 (catalogue); Dialictus viridatus , p. 1973 (catalogue); Moure & Hurd, 1987: Dialictus viridatus , p. 139 (catalogue); Gibbs, 2010b: Lasioglossum (Dialictus) viridatum Ƥ3, p. 351 (redescription, key).

Diagnosis. Female L. viridatum can be recognised by the following diagnostic combination: head wide (length/ width ratio = 0.94–0.96); mesoscutum imbricate, punctures moderately coarse, relatively sparse between parapsidal lines (i=1–2d); tegula reddish brown; mesepisternum strongly rugose ( Fig. 17 A); metapostnotum rugoso-carinulate reaching the posterior margin; T1 acarinarial fan with dorsal opening; metasomal terga brown, apical halves obscurely punctate; and T4 with sparse tomentum, partially obscuring surface. They are most similar to L. atwoodi , which has metapostnotal rugae almost but not reaching the posterior margin and T4 with only scattered tomentum, not obscuring surface.

Male L. viridatum are similar to females but may be further distinguished by head relatively long (length/width ratio = 1.01–1.02), flagellomeres long (length/width ratio = 1.56–1.64), mesoscutum reticulate anterolaterally, tarsi brownish yellow, apical impressed areas of metasomal terga impunctate, and apicolateral portions of S3–S5 with moderately dense plumose hairs.

Range. Nova Scotia west to Manitoba, south to North Carolina. USA: CT, IN, MA, ME, MI, MN, NC, NH, NY, WI. CANADA: MB, NB, NS, ON, PE.

DNA Barcode. Available. Multiple sequences.

Comments. Common.

The name-bearing type has lectotype labels from both Mitchell and Covell. No publication by either of these authors could be found that makes a valid lectotype designation. To maintain stable usage of the name, the specimen indicated above is designated as the lectotype.

Figures

FIGURE 17. Mesepisternum (A) without distinct change in sculpture (B) with distinct change in sculpture, indicated by arrow (L. dreisbachi). (From Gibbs 2010 b).