Spotted Wing Drosophila

SWD male''  Wisconsin  Minnesota 

Welcome to our web resources on spotted wing Drosophila. This is a central location for information on this invasive pest, including links to regional resources from Wisconsin and Minnesota.

2015 Update

  • August 31 - Susceptible crops must be protected or risk infestation by spotted wing Drosophila across the state.
  • August 25 - High pressure from spotted wing Drosophila continues. Susceptible crops must be protected or risk infestation.
  • August 18 - High pressure from spotted wing Drosophila continues and some growers are still not aware this pest is a statewide problem. Fortunately, susceptible crops can be protected.
  • August 11 - Spotted wing Drosophila activity has increased and requires careful management to prevent extensive fruit infestations, especially in blueberries and raspberries.
  • August 4 - Summer increase of spotted wing Drosophila continues. Ripening susceptible crops need to be protected.Summer increase of spotted wing Drosophila continues. Ripening susceptible crops need to be protected.
  • July 28 - Summer increase of spotted wing Drosophila is in full swing in all fruit production regions in Lower Michigan. Ripening susceptible crops need to be protected.
  • July 21 - Summer increase of spotted wing Drosophila continues in southern Michigan.
  • July 14 - The summer increase of spotted wing Drosophila has begun in southern Michigan.
  • July 7 - Spotted wing Drosophila numbers are still very low, but we have confirmed first detections this season of female SWD from traps in Antrim, Ingham and Livingston.
  • June 30 - No spotted wing Drosophila were caught in our statewide monitoring network traps this week. Reports from other trap lines are still very low to zero across the state.
  • June 23 - Trap catches are low to zero across Michigan; a few more southwest sites are reporting first catches this week.
  • First spotted wing Drosophila detected for 2015 – traps should be out already (June 16)
  • Spotted wing Drosophila statewide monitoring reports start next week (June 9)

Search for past reports at MSU Extension’s Fruit & Nuts News.

Some key articles from MSU Extension News:


The Spotted Wing Drosophila (SWD) is a vinegar fly of East Asian origin that can cause damage to many fruit crops. This small insect has been in Hawaii since the 1980s, was detected in California in 2008, spread through the West Coast in 2009, and was detected in Florida, Utah, the Carolinas, Wisconsin and Michigan for the first time in 2010. Because the flies are only a few millimeters long and cannot fly very far, natural dispersion between states is unlikely. Human-assisted transportation is a more likely cause of the recent rapid spread. It appears that this insect has become widely established through North America.

What crops are affected?

SWD has been detected in traps located near berry crops, grapes, cherries and other tree fruits. The flies have a preference for softer-fleshed fruit.

Status in Michigan

In fall 2010, SWD was detected in Michigan for the first time as part of a widespread Early Detection and Rapid Response program. SWD flies have now been detected in 22 counties in the southern peninsula of Michigan. Activity period spans from June through to late fall.

What is being done?

A SWD Response Team has been formed that combines the expertise of MSU entomologists, horticulturalists, Extension educators, and Michigan Department of Agriculture staff. This website will be the central location for dissemination of information about this insect. Check back for updates. This team is also helping to coordinate research projects to understand how best to protect fruit from infestation by this new pest.

Managing SWD

We are confident that the Integrated Pest Management (IPM) programs available for SWD control can be implemented to enable continued harvest of high-quality crops. See our fact sheets for English and Spanish information on monitoring for this pest, and recommendations for management in blueberries (last updated June 2014).

Important links

Funding for the SWD Response Team

The activities of the SWD Response Team are funded by Project GREEEN, the Michigan Department of Agriculture and Rural Development, US-EPAUSDA and Michigan grower organizations. A regional research and extension grant through the North Central IPM Center has also supported this website through a grant with the University of Wisconsin and University of Minnesota.

The MSU IPM Program maintains this site as an access point to pest management information at MSU. The IPM Program is administered within the Department of Entomology, fueled by research from the AgBioResearch, delivered to citizens through MSU Extension, and proud to be a part of Project GREEEN.