MSU Extension Integrated Pest Management

Distribution and history in the Great Lakes Region

Spotted wing drosophila (SWD), Drosophila suzukii, is an invasive pest that attacks a wide range of soft, thin skinned fruit crops, as well as many wild host plants. SWD is native to Asia and was first discovered in California
raspberries in 2008. It was first detected in Michigan in September 2010, in a trap set up by MSU researchers. It
is now a major pest of tart cherries, blueberries, fall red raspberries, and day-neutral strawberries. In some seasons, it can be a problem in June-bearing strawberries and sweet cherries. In Michigan, it will be commonly found infesting honeysuckle, mulberry, and brambles in wooded edges. SWD populations in the Great Lakes Region typically begin surging in July, growing rapidly until cold weather arrives in the fall.

Pest biology

Similar to other Drosophila flies (e.g., the common vinegar fly, D. melanogaster), when conditions are favorable,
SWD are capable of reproducing rapidly, with each female able to lay more than 300 eggs in her lifetime. SWD
can reproduce on a wide variety of substrates, including mushrooms and rotting fruit, but they are a significant
agricultural pest because they can start infesting fruit as it begins to ripen.