Tenn. – Experts with the University of Tennessee Institute of Agriculture are
sounding the alarm on a tiny new pest that can cause significant damage to many fruit
The spotted wing drosophila (SWD) 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 is equipped with 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 knowing whether the pest if 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
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 the website for UTIA Field Days and Special Events.
You can also find more information about SWD on the UT Institute
of Agriculture’s Soil, Plant Pest Center Facebook page, or by calling your
local UT Extension office, located in every county in the state.
UT Extension provides a gateway to the University of Tennessee as
the outreach unit of the Institute of Agriculture. With an office in every
Tennessee county, UT Extension delivers educational programs and research-based
information to citizens throughout the state. In cooperation with Tennessee
State University, UT Extension works with farmers, families, youth and communities
to improve lives by addressing problems and issues at the local, state and
Frank Hale, professor, Department of Entomology and Plant
Pathology, 615-832-6802, email@example.com
Rowsey, UTIA Marketing and Communications, 731-425-4768, firstname.lastname@example.org