Listen to this podcast on the Drosophila Fruit Fly and how it attacks berries and fruits.
If you’re growing fall raspberries or blueberries, chances are you’re starting to see this pest. Or you’re seeing the symptoms of this pest! If you’ve noticed your ripening blueberries or raspberries are shriveling on the plant or turn into a maggot filled mess after sitting on the counter for a few days, you probably have the spotted winged drosophila fruit fly.
This relatively new pest is the bane of fruit growers and is spreading. The small fly lays eggs on ripening fruits. The eggs hatch and the small maggots feed, causing the fruit to collapse and rot. Regular fruit flies, like those flying around your kitchen counter, lay eggs on fruits already breaking down. However, the spotted winged drosophila fruit fly has the ability to cut into the thick skins of unripe fruits to lay eggs. That’s a problem.
While researchers and growers scramble to come up with solutions, we do know a few things home gardeners can do. Start by growing summer bearing raspberries and early maturing blueberries. The fruit fly population tends to swell come late summer and fall. Clean up and discard dropped and infested fruits. Prune blueberries to be more open and sunny. Fruit flies like cooler places to hide. Cover smaller plantings with a fine mesh netting to exclude the flies. Mulch under plants with plastic to prevent the larvae from pupating on the ground near the plants. Harvest every few days and refrigerate the berries immediately to stop the eggs from hatching. The fruits are still edible. A recent guide from Michigan State University offers more control ideas for organic growers.