Adult spotted-wing drosophila are small, 2-3 mm in lengthg, and have a wingspan of 6-8 mm. Males are smaller than females. They can be easily distinguished from males of other Drosophila species or SWD females by a large dark spot on each wing, where their common name is derived from. Females have a strong saw-like ovipositor that is used to penetrate the skin of the host fruit and for laying the egg into the fruit. Eggs are white, 0.6 long and 0.2 mm wide. Each egg has two respiratory tubes which stick out of the fruit. There are three larval instars and in the third instar the larvae are about 3.9 mm long. The pupae of Drosophila suzukii are tan-brown and 3 mm long.
Contrary to other Drosophila species, D. suzukii females lay their eggs into healthy, unripe fruits. The larval development takes place in the fruit. The larvae pupate either fully or partly in the fruit, or outside the fruit on the ground.