MSU Extension Integrated Pest Management

With practice, identifying spotted wing drosophila (Drosophila suzukii) is possible using a hand lens in the field. For the novice, this will take some practice but it is achievable after seeing a few traps with spotted wing drosophila (SWD) captures. One of the biggest challenges is identifying SWD from among the many other small flies, including other species of drosophila captured in traps. This guide has been prepared based on experiences in Michigan, to help the user identify SWD.
Identifying spotted wing drosophila. Adult SWD are 2-3 mm long, have rounded abdomens, and may be seen on the outside of fruit or in traps. Flies are light yellow or brown with red eyes. Dark unbroken bands are seen across the abdominal segments. One major distinguishing characteristic is that the adult male SWD has one distinctive dot on each of its wings along the 1st vein (Figure 1). Male SWD also have two dark bands on each of the forelegs. These bands are known as combs and contain three to six teeth (Figure 2). Female SWD are harder to identify, as they do not have these wing spots. Female SWD have serrated ovipositors with two rows of serration that are longer than other vinegar fly species (Figure 3).