The spotted wing Drosophila (SWD), Drosophila suzukii (Matsumura) is a pest of soft fruit native to Asia, but was found in California starting in 2008, and in Washington and Oregon in 2009. Most Drosophila species, collectively known as vinegar flies, are attracted to overripe and rotting fruit for ovipositing sites, but SWD females have saw-like ovipositors which they use to lay eggs in ripening fruit, still on the plant.
Fruits targeted by this pest include strawberry, raspberry, blueberry, plum, peach, cherry, and grape. Damage is seen initially as tiny scar on the skin of the fruit, and then the skin collapses and may become moldy in the area where the egg was laid and the larva is developing. The larvae will feed inside the fruit for 5-7 days. Adult females can lay up to 350 eggs in a lifetime.
- WSU Mount Vernon NW WA Research Center Spotted Wing Drosophila Updates
- WSU Whatcom County Extension SWD Information
- FS049E: Spotted Wing Drosophila (SWD): Monitoring, Identifying, and Fruit Sampling
- WSU IPM Spotted Wing Drosophila Bulletin