Mostly robust medium-sized to large flies, partly or wholly metallic blue or green, sometimes polished black or with silvery, yellowish or golden microtomentum in a variable pattern, occasionally small, slender, and without metallic sheen, some species all yellow. Male seldom holoptic; upper facets of eye not much enlarged, but with frons always narrower than in female, and lacking orbital and outer vertical setae. Sexes sometimes with differing leg chaetotaxy, occasionally with marked difference in body color. Length 4-16 mm.