Lasioglossum (Dialictus) heterognathum (Mitchell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 118-119

Lasioglossum (Dialictus) heterognathum (Mitchell)

Dialictus heterognathus Mitchell, 1960: 397 . Ƥ.

Holotype. Ƥ USA, North Carolina, Grandfather Mt. , 27.vi.1952, [ NCSU]. Examined. Dialctus banksi Mitchell, 1960: 434 . 3. Lapsus calami .

Holotype. 3 USA, North Carolina, West End, 14.vi.1950, (Mitchell); [ NCSU]. Examined.

Taxonomy. Knerer and Atwood, 1963: Dialictus heterognathus 3, p. 167 (description); Knerer and Atwood, 1966a: D. heterognathus , p. 882 (synonymy); Krombein, 1967: Lasioglossum (Dialictus) heterognathum , p. 463 (catalogue); Hurd, 1979: Dialictus heterognathus , p. 1966 (catalogue); Moure & Hurd, 1987: Dialictus heterognathus , p. 103 (catalogue); Gibbs, 2010b: Lasioglossum (Dialictus) heterognathum Ƥ3, p. 136 (redescription, key).

Diagnosis. Female L. heterognathum can be recognised by the following diagnostic combination: hypostomal carinae divergent towards mandible bases ( Fig. 10 B), gena wider than eye, mesoscutal punctures fine, and scopa present. They are similar to L. apocyni and L. imitatum , which both have hypostomal carinae parallel and female L. imitatum have T3–T4 with coarse white hairs ( Fig. 20 A).

Male L. heterognathum can be recognised by the following diagnostic combination: facial tomentum dense only on lower paraocular area; flagellomeres elongate (length/width ratio = 1.50–1.85); dorsolateral angles of pronotum obtuse; mesoscutum dull due to weak microsculpture, punctures sparse between parapsidal lines (i=2–3d); mesepisternal punctures fine but distinct (i=1–3d); and apical impressed areas of the metasomal terga impunctate. They are most similar to L. wheeleri , which have pronotal dorsolateral angles acute.

Range. Nova Scotia to Ontario, west to Minnesota, and south to North Carolina. USA: CT, ME, MI, MN, NH, NY, NC, PA, VT, WV, WI. CANADA: NB, NS, ON, PQ.

DNA Barcode. Available. Multiple sequences.

Comments. Common. See Gibbs (2010b).

Figures

FIGURE 10. Hypostomal carina variation in female Lasioglossum (Dialictus). (A) subparallel (L. connexum); (B) divergent (L. heterognathum); (C) divergent (L. reticulatum).

FIGURE 20. T 3 – T 4 (A) with uniquely coarse, evenly spaced, longitudinal hairs (L. imitatum); (B) without coarse hairs (L. laevissimum). (From Gibbs 2010 b).