Spotted Wing Drosophila

Another TMG Winter School alert:  an invasive fruit fly

Warning:  this is so gross

Dr. Frank Hale from UT Extension told us about SWD.  Drosophila suzukii, the Spotted Wing Drosophila (SWD) is native to southeast Asia.  It was first spotted in California in 2008.  Since then, it has been detected in Washington, Florida, Utah, Michigan, Wisconsin, Kentucky, Louisiana and - in 2011 - in Unicoi County in Tennessee.  This nasty little critter lays eggs in fruit crops.  Strawberry, blueberry, grape, cherry, apple, fig, you name it.  

Females lay eggs under the skin of ripe fruit shortly before harvest. Larvae hatch and begin to feed within the fruit, causing softening in the area of feeding. There can be several larvae in a fruit, which hastens softening and fruit collapse. Holes the size of pin pricks are evident within the soft areas of infested fruit. These holes result from egg laying and are used as breathing holes by larvae. In addition, these holes provide entry points for diseases such as brown rot and botrytis.

Adult Female - note ovipositor

Adult Male - spotted wings

Egg-laying holes in blueberries

Pupae in blueberries

We told you this was gross.  We asked what the effect would be on a person who ate infected fruit and Dr. Hale said, "Additional protein."  He's funny.

We should warn our grower friends about this pest.  They should make traps and put them out at least 2 weeks before the fruit will be ripe.  Learn how to make a trap here.

SWD trap