Photo by Drees . A robber fly , Laphria sp. Photo by Drees. Photo by Drees.
Species vary in appearance and some mimic wasps and bees.
Most species are gray to black, hairy-bodied, have a long, narrow, tapering abdomen containing segments that may be banded, patterned or contrasting in color. The heads of adults have a depression between the eyes when viewed from the front. They have long, strong legs for grabbing prey. Some robber flies resemble bees in a appearance but can readily be separated since true flies have only one pair of wings. Many have wings marked with darker patterns and they hold their wings outstretched.