Lasioglossum (Dialictus) pilosum (Smith)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 157-158

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Lasioglossum (Dialictus) pilosum (Smith)


Lasioglossum (Dialictus) pilosum (Smith)

Halictus pilosus Smith, 1853: 71 . Ƥ.

Holotype. Ƥ North America [ BMNH: B.M. Type 17a 1000]. Examined. Halictus floridanus caesareus Cockerell, 1916: 11 . Ƥ.

Holotype. Ƥ USA, New Jersey, Ocean Grove, 1893 [ NMNH: 27761]. Examined.

Taxonomy. Robertson, 1895: Halictus pilosus 3, p. 117 (description); Robertson, 1902 b: Chloralictus pilosus , p. 248 (key); Cockerell, 1905: Halictus pilosus Ƥ, p. 351 (redescription); Viereck, 1916: Halictus (Chloralictus) pilosus , p. 706 (key); Michener, 1951: Lasioglossum (Chloralictus) floridanum caesareum , p. 1113, L. (C.) pilosum , p. 1116 (catalogue); Mitchell, 1960: Dialictus pilosus pilosus Ƥ 3, p. 413 (redescription); Mitchell, 1962: Dialictus pilosus pilous , p. 547 (synonymy); Krombein, 1967: Lasioglossum (Dialictus) pilosum pilosum , p. 465 (catalogue); Dialictus pilosus pilosus , p. 1970 (catalogue); Moure & Hurd, 1987: Dialictus pilosus pilosus , p. 123 (catalogue); Gibbs, 2010 b: Lasioglossum (Dialictus) pilosum Ƥ 3, p. 253 (redescription, key, synonymy).

Diagnosis. Female L. pilosum can be recognised by the following diagnostic combination: head long (length/width ratio = 1.03–1.08), clypeus apicolateral margins subparallel, mesoscutal punctures dense throughout (i<d), metapostnotum rugoso-carinulate, and metasomal terga metallic with dense yellowish tomentum. They are similar to L. floridanum , L. leucocomum and L. succinipenne . Female L. floridanum have fine metapostnotal rugae, which are obscure among background microsculpture. Female L. leucocomum and L. succinipenne have convergent apicolateral margins of the clypeus.

Male L. pilosum can be recognised by head long (length/width ratio = 1.13–1.17); eyes strongly convergent below (UOD/LOD ratio = 1.35–1.64); clypeus yellow distally; mesoscutal punctures very dense, contiguous medially; metapostnotum rugoso-carinulate; and metasomal terga metallic, punctures dense and distinct. They are most similar to L. floridanum , L. leucocomum and L. succinipenne . Male L. floridanum have weak metapostnotal rugae and usually lack a clypeal maculation. Male L. leucocomum have sparser mesoscutal punctures medially. Male L. succinipenne have punctures visible on the mesepisternum.

Range. Nova Scotia west to Wisconsin, south to Georgia. USA: CT, GA, IN, MA, MD, ME, MI, NC, NH, NJ, NY, PA, TN, VA, WI, WV. CANADA: NS, ON, PQ.

DNA Barcode. Available. Multiple sequences.

Comments. Common.

Gibbs (2010 b) narrowed the usage of this name and raised the names L. leucocomum and L. floridanum to species level, as discussed above. Gibbs (2010 b) reported a less southerly range for L. pilosum but additional material has since been identified from CUIC.


Smithsonian Institution, National Museum of Natural History


Department of Natural Resources, Environment, The Arts and Sport


Cornell University Insect Collection














Lasioglossum (Dialictus) pilosum (Smith)

Gibbs, Jason 2011

Halictus pilosus

Smith 1853: 71