University of Tennessee fruit and bug experts are sounding the alarm on a tiny new pest in the state. Spotted Wing Vinegar Fly can devastate many small fruit crops.

The spotted wing drosophila is a vinegar fly sometimes inaccurately called a fruit fly from Asia.  It was first detected in California in 2008. In 2011, SWD had reached blueberries in East Tennessee. By 2013 SWD damage had spread to 23 Tennessee counties, from Greene County in the east to Gibson County in the west.

The female SWD has a serrated egg laying structure called an ovipositor that allows her to pierce the flesh of healthy fruit and insert tiny eggs inside. The piercing of the fruit allows yeast, fungi and other microorganisms to enter and begin the process of decay. Once the larvae hatch, they feed on the fruit, causing it to further decompose.

The SWD targets strawberries, blueberries, blackberries, raspberries, grapes, figs, persimmons, cherries and other soft, thin-skinned fruit. Berries are especially susceptible. Wherever it has been found, the SWD has caused considerable damage to fruit crops.

Because this pest is so new to the area, entomologists are still evaluating the best methods for control. Frank Hale, a UT Extension entomologist, says the first step is to know whether the pest is present. He recommends setting traps within fruit crops baited with yeast, sugar and water. If this invasive pest is detected, he says weekly insecticide applications should begin as soon as the fruit show the first sign of their ripening color.

You can speak directly with UT experts about this and other crop pests at several UTIA-sponsored events this summer, including the Fruits of the Backyard Field Day on Tuesday, June 17, at the Middle Tennessee AgResearch and Education Center in Spring Hill and the Summer Celebration Lawn and Garden Show on Thursday, July 10, at the West Tennessee AgResearch and Education Center in Jackson.

For more information on these events, visit UTIA Field Days and Special Events.