Description of the insect

Adults are small brownish-yellow to orange-yellow flies with black bands on the abdomen. The eyes of living imagines are bright red in color. Males are distinguished from females by their smaller size (2.6-2.8 mm) and the presence of a dark spot on the anterior end of each of the two wings. In addition, two rows of bristles are located on each anterior tarsus.

Females have no spots on the wings or bristles on the tarsi. They can be differentiated from other species thanks to the clearly visible ovipositor. This equipped with black teeth and thick over 1/3 to 2/3 of the length makes it possible to lay eggs in under-ripe fruits (figures 1 and 2).

The legless, cylindrical (2-3 mm long), white larva has raised posterior stigmas at one end (Figure 3). This larva goes through three larval stages before reaching pupation. The pupa, red-brown in color, measures 2-3mm in length. Each pupa has a growth (stigma) at each end. The anterior stigma of the pupa takes the form of two characteristic small fins (Figure 4).

The adult may be confused with other species of Drosophila with spotted wings.

Bibliography: Fredon Corse, IFV Sud-Ouest