Spotted wing drosophila on raspberry in Northern California. Males have spots on the ends each of their wings, while females do not. Image from the UC ANR Strawberry and Caneberry Blog, courtesy Ed Show.
Formerly known as the cherry vinegar fly, the spotted wing drosophila (Drosophila suzukii) has rapidly progressed from recently detected invader to significant pest of fruit in California. The fly was first detected in fall 2008 and was confirmed in backyard and commercial cherry plantings in spring 2009. Experts in California believe it has been present for at least a year prior to that detection. On August 4, 2009, the spotted wing drosophila was detected in Hillsborough County in central Florida.
What makes the spotted wing drosophila a concern to growers and entomologists alike is the fact that its serrated ovipositor (egg laying devise) allows it to attack sound fruit. Of the nearly 1500 known drosophila species, only 2 are pests of sound fruit, one of which is the spotted wing drosophila. Most other drosophila flies feed on the microorganisms that inhabit rotting fruit or plant tissue, and therefore are not typically crop pests.
Any soft fruit is likely at risk for damage by this pest, which includes caneberries, strawberries, peaches, grapes, blueberries, and figs. Research in California indicates that the fly completes a generation in approximately 2 weeks. Infested fruit appears bruised from the outside, and small (1-2 mm) larvae feed internally.
Because they are present in Florida, it's only a matter of time before the spotted wing drosophila makes it way to North Carolina. I will be working with county agents this winter to establish a monitoring network in high risk counties. Please contact your county agent or myself if you suspect spotted wing drosophila damage in your fruit.
You can find more information on spotted wing drosophila at the following links: