Lasioglossum (Dialictus) oblongum (Lovell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 154-155

Lasioglossum (Dialictus) oblongum (Lovell)

Halictus oblongus Lovell, 1905a: 40 . Ƥ 3.

Syntypes. Ƥ3 USA, Maine, Waldoboro, 24.viii, on Eupatorium perfoliatum [depository unknown].

Taxonomy. Lovell, 1905a: Halictus versans 3, p. 39 (misdet.); Lovell, 1908: Halictus (Chloralictus) oblongus 3, p. 38 (description); Michener, 1951: Lasioglossum (Chloralictus) oblongum , p. 1115 (catalogue); Mitchell, 1960: Dialictus oblongus Ƥ3, p. 409 (redescription, key); Krombein, 1967: Lasioglossum (Dialictus) oblongum , p. 465 (catalogue); Hurd, 1979: Dialictus oblongus , p. 1969 (catalogue); Moure & Hurd, 1987: Dialictus oblongus , p. 116 (catalogue); Gibbs, 2010b: Lasioglossum (Dialictus) oblongum Ƥ3, p. 211 (redescription, key).

Diagnosis. Female L. oblongum can be recognised by the following diagnostic combination: head wide (length/ width ratio = 0.94–0.95); supraclypeal area densely punctate (i≤d); mesoscutum imbricate, punctures moderately sparse between parapsidal lines (i=1–2d); mesepisternum weakly rugose; metapostnotum coarsely carinate with shining interstitial areas; T1 acarinarial fan with wide dorsal opening; and metasomal terga polished, appressed tomentum virtually absent.

Male L. oblongum are similar to females but may be further distinguished by the head relatively elongate (length/ width ratio = 0.98–1.01), flagellomeres moderately elongate (length/width ratio = 1.54–1.58), and S3 –S5 apicolateral portions with moderately dense, plumose hairs.

Range. Quebec, Ontario, south to Virginia, east to Massachusetts. USA: DC, DE, IN, MA, MD, NJ, NY, VA, WI. CANADA: ON, PQ.

DNA Barcode. Available. Multiple sequences.

Comments. Uncommon.

Lasioglossum oblongum has been reported to nest in rotten wood (Sakagami & Michener 1962). Individuals of L. oblongum , in the sense used here, have indeed been collected from under the bark of fallen logs.

The name L. oblongum has been applied in a sense believed to be consistent with standard usage in the last 50 years (see Mitchell 1960; Gibbs 2010b). Until the type series is located, it remains unclear if the species referred to here as L. oblongum is the same as the one described by Lovell (1905a).