Spotted-Wing drosophila

Taylor Hulse
Crop Production Services
The Drosophila suzukii (aka: spotted-wing drosophila, vinegar fly, dragon fruit fly), is the newest threat to Oregon Agriculture, namely, Oregon’s fruit industry. As many of you have heard, this pesky fly has the ability to deposit her eggs in many fresh, ripening berries- when no other species of fruit fly would be able to. There has been documented infestation in Blueberries, Raspberries, Boysenberries, Strawberries, Blackberries, Cherries, Elderberries, Apples, Pears, Nectarines, Peaches, Plums, Grapes, Tomatoes, and possibly Oranges (just to name a few). The significance of this fly has yet to be realized as it showed up only last year and has yet to have the needed time to fully establish itself. Population numbers are already far beyond eradication, leaving suppression and attempted control as our only options.

Originally from Japan and Southeast Asia, the SWD (spotted-wing drosophila) made its way to Hawaii in the 1980’s and was confirmed in Florida, California, Italy, and France last year. In August of 2009, the fly was found in British Columbia, Washington and 12 counties in Oregon (mostly along the I-5 corridor, but as far away as Wasco and Umatilla counties).

All female fruit flies have an ovipositor that allows them to deposit their eggs; most often in rotting fruit that’s skin is already punctured. What separates the SWD female fly is her serrated edged ovipositor that enables her to literally ‘saw’ through ripe/ripening fruit. The eggs she deposits then hatch within 1-3 days and begin feeding, causing a depression in the skin of the fruit and leading to secondary infections.

There is no tolerance for SWD eggs or larva in fruit, therefore prevention is the only solution. It is important to note that while you may control all SWD within your orchard or field, they are still infesting the wild blackberries in ditches and in fencerows. Therefore, when your insecticide wears off, the flies will be available to immediately re-infest your orchard or field. Any approach to suppression or control will have to include wild blackberries and other wild host plants.

For more detailed information regarding the SWD lifecycle, control options, temperature dependence, etc., visit Oregon State University’s SWD website: OSU SWD Website

While there is much more information regarding this fly, the overall purpose of this article is to let you, our valued customers know that we are aware of this new pest and are currently developing strategies to keep your crops protected and SWD free. Rest assured, CPS carries all of the required products and expertise that you may need. Please call with any questions or additional information regarding our systematic approach to SWD control.