What is "ubristes"

Ubristes is a genus of hoverflies, with 61 known species. All are characterized by their metatibiae, which are usually enlarged, but always with a brush of long pile along the dorsal edges. These flies are probably mimics of the stingless bees in the tribe Meliponini.

The presence or absence of the appendix on vein R4+5 is variable within this group. They are further divided into the subgroups Hypselosyrphus, Stipomorpha, and Ubristes by the shape of their abdomens.