University of Maryland Extension

Spotted Wing Drosophila

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spotted wing drosophila

May is the time to look for spotted wing drosophila (SWD), a relatively new pest of fruit plants in Maryland. Jerry Brust, Ph.D., Extension Vegetable Specialist gives you the details and photos in his (PDF) fact sheet. Two popular backyard fruit crops, blackberry and raspberry, are favorite host plants for SWD.

The Spotted Wing Drosophila (SWD), Drosophila suzukii, is a small vinegar fly with the potential to damage many fruit crops. In the North Central region, it was first detected in Michigan in late September 2010. Unlike most other vinegar flies that require damaged fruit to attack, SWD causes damage when the female flies cut a slit and lay eggs in healthy fruit. 

Make your own simple trap to monitor for this destructive fruit fly by (PDF) following these instructions from Oregon State. The trap consists of a clear plastic drink cup and apple cider vinegar. The yellow sticky cards make it easier to attract and identify SWD. There are many online suppliers of yellow sticky cards. You can also use the trap without the cards.

larva inside fruit
Photo: Hannah Burrack, NC State University,Bugwood.org
SWD larvae inside cane fruit

larva inside blueberry
Photo: Frank A. Hale, UT, Bugwood.org
SWD larvae inside blueberry

Also use the search box in the upper right hand corner of our website to search the University of MD Extension site for additional information on spotted wing drosophila.

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