Lasioglossum

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216: 11-12

publication ID

http://doi.org/ 10.5281/zenodo.1049595

publication LSID

lsid:zoobank.org:pub:B5AF6DF4-D3A7-4942-A94F-CC051D8074CF

persistent identifier

http://treatment.plazi.org/id/9A5987DB-A71C-FFBC-0A97-8E0AFC0C0273

treatment provided by

Plazi

scientific name

Lasioglossum
status

 

Diagnosis for Lasioglossum   ( Dialictus   ) in eastern North America

Lasioglossum   ( Dialictus   ) are small (3.1–8.1 mm), andreniform bees, which can be separated from most other bees in eastern North America by the following combination of characters: basal vein strongly arched, distal veins of forewing weak (1 rs-m, 2 rs-m, 2 m-cu, and the distal abscissa of M; 1 rs-m sometimes absent) ( Fig. 5 View FIGURE 5 ), and female inner metatibial spur pectinate with long branches.

Most species of L. ( Dialictus   ) have metallic reflections of the head and mesosoma that distinguishes them from all other Lasioglossum   s. l. in eastern North America. Additional characters that further assist in distinguishing Dialictus   from other eastern North American Lasioglossum   subgenera are as follows. Lasioglossum   s. s. and L. (Leuchalictus) have vein 1 rs-m strong and are typically much larger than Dialictus   . Female L. (Hemihalictus) have a serrate inner metatibial spur and both sexes usually lack vein 1 rs-m. Female L. ( Sphecodogastra   ) have a unique metafemoral scopa consisting of a single linear series of coarse hairs.

The subgenus L. ( Evylaeus   ) is the most difficult to distinguish from L. ( Dialictus   ) with black integument. Female Evylaeus   may have the inner metatibial spur serrate, denticulate, or pectinate but the branches are usually shorter than those of Dialictus   . Male Evylaeus   have the inner dorsal margins of the gonocoxites parallel basally for over 1 / 2 to 2 / 3 their length and are widely divergent apically. Lasioglossum   ( Evylaeus   ) in eastern North America usually have lateral and posterior surfaces of propodeum completely separated by lateral propodeal carinae and mesepisternum rugulose.

In contrast, all female L. ( Dialictus   ) in eastern North America have pectinate inner metatibial spurs with long branches and all male L. ( Dialictus   ) have the inner dorsal margins of the gonocoxites more evenly and weakly divergent over their entire length (except L. (D.) rufulipes   and L. (D.) testaceum   ). Black Dialictus   may have the mesepisternum distinctly punctate or very coarsely rugose which is never seen in eastern Evylaeus   . Female black Dialictus   with weak mesepisternal sculpture have lateral and posterior surfaces of propodeum incompletely separated by the lateral propodeal carinae. Species of black Dialictus   with lateral and posterior propodeal surfaces completely separated (e. g. L. pectorale (Smith))   are always more coarsely sculptured on the mesosoma than Evylaeus   .