The adults are 8–12 mm long. The females are slightly larger than the males, and have a much larger space between their red compound eyes. The mass of pupae can range from about 8 to 20 mg under different conditions. Each female fly can lay approximately 500 eggs The eggs are white and are about 1.2 mm in length. Within a day, larvae (maggots) hatch from the eggs and are pale-whitish, 3–9 mm long. At the end of their third instar the maggots crawl to a dry cool place and transform into pupae, coloured reddish or brown and about 8 mm long. The adults live from 2-3 weeks. The flies reproduction depend on warm temperatures; generally, the warmer the temperature the faster the flies will develop. In winter, most of them survive in the larval or the pupa stage in some protected warm location.