Characteristics
Sobarocephala flaviseta
is a pale species with white shoulder patches that are often ill-defined, and the frons narrows towards the back of the head, which is exaggerated by widely-separated antennae and a bulging face and parafacial. The male head is often much paler and sometimes even white (as figured to right), but this is infrequently retained in preserved material. The female abdomen is also diagnostic, having a narrow light brown stripe on tergites 3-5.

Similar species
Sobarocephala flaviseta is most similar in appearance to S. latifacies. Both species are very pale and have a posteriorly-narrowing frons, but S. latifacies has black bristles (not brown), brown shoulders, a smaller yellow head, an open cell bm, and an unusually-pigmented female abdomen: tergites 6 and 7 are dark, tergites 2-5 have a medial stripe (usually reduced to anteromedial spots), and the posterior and anterior margins are sometimes brown.

Sobarocephala atrifacies (Florida) also has white shoulders, but the scutellum and the posterolateral corners of the scutum are also white and there is a strong black spot in front of the scutellum.

Distribution
Sobarocephala flaviseta is the most widespread of the North American Sobarocephala, occurring throughout the eastern United States and much of eastern Canada, ranging northwards from Texas into the midwestern states, Alberta and British Columbia.

Biology
Numerous specimens of this species have been collected in Malaise traps and it can be locally abundant, particularly in moist, mixed deciduous woodlands.