Classification of the bee tribe Augochlorini (Hymenoptera, Halictidae). Bulletin of the AMNH ; no. 250

Abstract

The halictid bee tribe Augochlorini is revised at the level of genus and subgenus. Forty-one genera and subgenera are recognized with two being extinct. New subgenera of Augochlora, Electraugochlora, and of Oligochlora, Soliapis, are described for new fossils from Tertiary amber of the Dominican Republic. Complete taxonomic histories are given along with information on revisions at the species level, biological studies, and general distribution for each family- and genus-group taxon. The following subgenera are newly synonymized: Aethechlora new junior subjective synonym of Oxystoglossella, Mycterochlora new junior subjective synonym of Augochlora, Vachalius new junior subjective synonym of Neocorynurella, and Neocorynuroides new junior subjective synonym of Neocorynura. The group Glyptochlora is resurrected from synonymy as a valid subgenus of Augochloropsis. The males of Chlerogella and Micrommation are described for the first time. A key to the genera and subgenera of the tribe is presented along with a key to the species of the rare Augochloropsis (Glyptochlora). Suprageneric relationships in the tribe are explored cladistically. Characters of adult external morphology (72 characters) and ethology (12 characters) are coded for all recognized augochlorine genera as well as outgroups from the Halictini, Nomioidini, and Nomiinae. Results of the cladistic analysis are remarkably resolved but not very robust. The cladogram is summarized and infratribal groups defined. Most notably, the tribe is divided into two monophyletic subtribes: the Corynurina (new subtribe), containing the southern South American genera Corynura, Halictillus, Rhectomia, and Rhinocorynura; and the nominate subtribe, Augochlorina. Implications of the cladistic analysis on diversification in the Augochlorini and evolutionary patterns within the tribe are discussed. New distribution records are given for three species which extend the known ranges of their respective genera. Augochlora essequibensis is a new junior subjective synonym of A. nigrocyanea while A. cladopyga, A. seminigra, Augochlorella bidentata, Halictus caucasicus, H. cerasis, H. chrysaspis, H. myrrhites, H. simotes, and Pereirapis rhizophila are all new junior subjective synonyms of P. semiaurata. Megalopta intermedia, Augochlora nitidior, Augochlorella eusticta, Augochlorodes clementis, and Augochloropsis scabriceps are all recognized as nomina nuda. Vachalius cosmetor, from Colombia and Venezuela, is transferred to Neocorynurella while Corynura biciliata, from Costa Rica, is recognized as a species of Halictini and is transferred to the genus Lasioglossum (Evylaeus) (new combinations). Four fossil and recent species new to science are described as Augochlora (Electraugochlora) leptoloba (fossil), Augochlora (Oxystoglossella) rightmyerae (extant), Oligochlora (Soliapis) rozeni (fossil), and Pseudaugoehlora pulchra (extant).