Lasioglossum (Dialictus) imitatum (Smith)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 119-120

Lasioglossum (Dialictus) imitatum (Smith)

Halictus imitatus Smith, 1853: 71 . 3.

Holotype. 3 North America [ BMNH: B.M. type 17a 999]. Examined. Halictus inconspicuus Smith, 1853: 73 . Ƥ.

Holotype. Ƥ North America [ BMNH: B.M. type 17a 1007]. Examined. Halictus stultus Cresson, 1872: 254 . Ƥ

Lectotype. Ƥ USA, Texas, Bosque Co., (G.W. Belfrage); [ ANSP: 2113] designated herein. Examined. Chloralictus sparsus Robertson, 1902: 249 . Ƥ3.

Lectotype. Ƥ USA, Illinois, Macoupin Co., Carlinville, 2.vi.1886 (C. Robertson); [ INHS: 1293] by W. E. LaBerge (in

Webb 1980). Examined.

Halictus hortensis Lovell, 1905a: 39 . Ƥ.

Lectotype. Ƥ USA, Maine, Waldoboro, on “cultivated blackberry”, 19.vi, (Lovell); [NMNH: 71568] designated herein.

Examined.

Halictus (Chloralictus) insolitus Sandhouse, 1924: 41 . 3

Holotype. 3 USA, Iowa, Vinton, 23.vi.1922 [ NMNH: 26446]. Examined. Dialictus lectus Mitchell, 1960: 438 . 3.

Holotype. 3 USA, Georgia, Kennesaw Mt., 1.ix.1946, [ NCSU]. Examined.

Taxonomy. Cockerell, 1905: Halictus inconspicuus 3, p. 349, H. imitatus Ƥ, p. 350 (tax. notes); Lovell, 1908: Halictus hortensis 3, p. 39 (description); Viereck, 1916: Halictus (Chloralictus) sparsus , p. 706 (key); Michener, 1951: Lasioglossum (Chloralictus) imitatum , p. 1114, L. (C.) inconspicuum , p. 1114, L. (C.) insolitum , L. (C.) sparsum , p. 1027 (catalogue, synonymy); Michener, 1953: Lasioglossum (Chloralictus) sparsum , p. 1027 (larva); Krombein, 1958: Lasioglossum (Chloralictus) inconspicuum , p. 230, (catalogue); Mitchell, 1960: Dialictus imitatus 3, p. 400, D. inconspicuus Ƥ, p. 400 (redescription, key); Knerer and Atwood, 1962b: D. imitatus , p. 168 (synonymy); Krombein, 1967: Lasioglossum (Dialictus) imitatum , p. 464; L. (D.) lectum , p. 464 (catalogue); Hurd, 1979: Dialictus imitatus , p. 1967, D. insolitus , p. 1967, D. lectus , p. 1968 (catalogue); Moure & Hurd, 1987: Dialictus imitatus , p. 105, D. insolitus , p. 109, D. lectus , p. 110 (catalogue); Pesenko et al., 2000: Evylaeus imitatus , p. 46 (review); Gibbs, 2010b: Lasioglossum (Dialictus) imitatum Ƥ3, p. 156 (redescription, key, synonymy).

Diagnosis. Female L. imitatum can be recognised by the distinct coarse hairs on T3–T4 ( Fig. 20 A). They may be further distinguished by size small (3.4–5.0 mm), gena wider than eye, hypostomal carinae parallel, punctures fine, and sculpturing weak throughout.

Male L. imitatum can be recognised by the following diagnostic combination: size small (4.2–4.3 mm); head moderately elongate (length/width ratio = 1.00–1.02); moderately facial tomentum sparse, except on lower paraocular area; mesoscutum weakly imbricate, punctures fine punctures, sparse between parapsidal lines (i=1.5–2.5d); hypoepimeral area and lower mesepisternum obscurely punctate; metapostnotum smoothly rounded onto posterior surface; and apical impressed areas of metasomal terga impunctate.

Range. Nova Scotia, south to Florida and west to Alberta, California. USA: AL, AR, AZ, CO, CT, GA, IA, IL, IN, KS, KY, MA, ME, MI, MN, MS, NC, NY, PA, PE, SC, SD, TN, TX, VA, WI, WV. CANADA: MB, NS, ON, PQ, SK.

DNA Barcode. Available. Multiple sequences.

Comments. Common.

Lasioglossum imitatum is known to form eusocial colonies (Michener & Wille 1961; as L. inconspicuum ).

The specimen of Halictus stultus indicated above is designated herein as the lectotype to ensure stability in the application of the name. Some of Cresson’s syntype series include more than one species, which could potentially lead to taxonomic confusion. Likewise, the specimen of Halictus hortensis indicated above is designated as the lectotype to ensure nomenclatural stability.

Figures

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).