Black-onion-fly
Guides
Tritoxa flexa
Black Onion Fly
Tritoxa flexa, commonly known as the Black Onion Fly, is a Nearctic species of picture-winged fly in the family Ulidiidae. It was first described by Wiedemann in 1830 and is one of seven recognized species in the genus Tritoxa. The species possesses distinctive patterned wings characteristic of ulidiid flies. A 2021 revision of the genus provided species illustrations, distribution maps, and a diagnostic key to differentiate T. flexa from congeners.