Length: males 14-24 mm; females 20-22 mm
Wing length: males 11-15 mm; females 16-17 mm
Traits of the adult to watch for include: a completely yellow face; yellow to light brown antennae; yellow femora and tibiae, with the tarsi somewhat darker. Wings cloudy but unpatterned, typically darker at the apical end.
These loud flies are Yellowjacket mimics. Though completely harmless, their buzz can be quite intimidating. It should be added that this loud buzz is very un-yellowjacket-like!
Eaton and Kaufman (2007) tell us "This is the 'news bee' of folklore, named for its occasional habit of hovering in front of a person and 'giving them the news.'"
Milesia scutellata is very similar, and can only be reliably separated from Milesia virginiensis by an expert with a dissecting kit. Fortunately, range can help with identification, with Milesia scutellata is found in southeastern states such as North Carolina, Florida, Mississippi, Alabama, and Louisiana.
Maier and Waldbauer (1991) report that Milesia virginiensis pursues a dual mating strategy, with males seeking females at flowering plants early in the morning, and then moving their quest to the oviposition sites (areas with appropriate decaying material for the larvae to feed on) by late morning.
American Insects site