Synonyms and other taxonomic changes
Range
Most diverse in North America, also across Africa, Asia, and Europe
(1)Remarks
Differences in the shape of the pygidial plate are used for generic ID of males (shorter and broadly rounded in Epeolus; narrower and with sinuate margins in Triepeolus). This can be difficult to see even in pinned specimens so many males were described in the wrong genus, even by Cockerell and Mitchell! In females the obvious difference is the extent and configuration of a hair patch called the pseudopygidial area (shorter and more transverse in Epeolus). These hairs are often silvery. (J.S. Ascher's comment)