Lasioglossum (Dialictus) smilacinae (Robertson)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 180-181

Lasioglossum (Dialictus) smilacinae (Robertson)

Halictus smilacinae Robertson, 1897: 322 . Ƥ.

Lectotype. Ƥ USA, Illinois, Macoupin Co., Carlinville, 21.iii.1894 (C. Robertson); [INHS: 16247] by W. E. LaBerge (in Webb

1980). Examined.

Halictus zophops Ellis, 1914: 97 . Ƥ. [new synonymy]

Holotype. Ƥ USA, Colorado, Boulder, 13.iv.1913, (M.D. Ellis); [ UCMC]. Examined. Dialictus philanthanus Mitchell, 1960: 441 . 3. [new synonymy]

Holotype. 3 USA, North Carolina, Mecklenburg Co. , 3.vi.1957 (C.F. Smith); [ NCSU]. Examined.

Taxonomy. Robertson, 1902b: Chloralictus smilacinae , p. 249 (key); Michener, 1951: Lasioglossum (Chloralictus) smilacinae , p. 1118; L. (C.) zophops , p. 1118 (catalogue); Mitchell, 1960: Dialictus laevissimus , p. (misdet., incorrect syn.) Krombein, 1967: Lasioglossum (Dialictus) philanthanum , p. 465 (catalogue); Hurd, 1979: Dialictus zophops , p. 1973 (catalogue); Moure & Hurd, 1987: Dialictus philanthanus , p. 122, D. zophops , p. 142 (catalogue); Gibbs, 2010b: Lasioglossum (Dialictus) laevissimum , p. 170 (misdet.); L. (D.) zophops Ƥ3, p. 368 (redescription, key).

Diagnosis. Female L. smilacinae can be recognised by the following diagnostic combination: size large (6.1–7.1 mm); head wide (length/width ratio = 0.92–0.94); mesoscutum imbricate-tessellate, punctures sparse punctures between parapsidal lines; mesepisternum rugulose; propodeal oblique carina well-developed; T1 acarinarial fan without dorsal opening; metasomal terga brown, apical impressed areas distinctly punctate; and T2 with sparse apical fringes visible in dorsal view. Similar species include L. gotham . L. laevissimum and L. versatum . Female L. gotham have more polished integument due to weaker microsculpture, obscure mesepisternal punctures, and T1 acarinarial fan with narrow dorsal opening. Female L. laevissimum have apical halves of metasomal terga impunctate and T2 lacks apical fringes visible in dorsal view. Female L. versatum have T1 acarinarial fan with wide dorsal opening.

Male L. smilacinae are similar to females and may be further distinguished by head longer (length/width ratio = 0.95– 0.99), mesepisternal punctures distinct, mesoscutum relatively polished, dorsolateral angle of pronotum obtuse, and apical impressed margins of metasomal terga with widely scattered punctures. They are most similar to L. gotham , L. obscurum and L. wheeleri . Male L. gotham have a narrow band of relatively dense punctation on base of apical impressed areas of metasomal terga. Male L. obscurum have head longer (length/width ratio = 1.02–1.05) and apical impressed areas of metasomal terga impunctate. Male L. wheeleri have dorsolateral angle of pronotum acute and apical impressed areas of metasomal terga impunctate.

Range. Southern Ontario, south to Maryland and west to Colorado. USA: CO, CT, GA, IA, IL, KS, MA, MD, ME, MI, MO, NC, NJ, NY, PA, SC, VA, WI, WV. CANADA: ON, PQ.

DNA Barcode. Available. Multiple sequences.

Comments. Common.

Lasioglossum smilacinae was previously considered a junior synonym of L. laevissimum . The lectotype was examined in 2007 and it was thought that the synonymy, first made by Mitchell (1960), was valid. Subsequently, L. zophops was reported to occur in eastern North America ( Gibbs 2010b). The lectotype was re-examined in 2011 and it is now evident that the synonymy was incorrect and L. smilacinae is the valid name for the species previously reported as L. zophops . The new synonymy with D. philanthanus was made possible by comparative study to male L. smilacinae and the related species L. gotham .