Cooperative Extension at Highmoor Farm

Spotted Wing Drosophila Alert: August 24, 2017

David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology

Spotted wing drosophila trap captures continue to increase as we move later into the season. (See table below.) Such high fly numbers will cause significant infestations of larvae in any ripening soft fruit, especially raspberries, blackberries, blueberries and day-neutral strawberries. Consistent spray coverage of susceptible crops is now necessary to prevent fruit infestation. We recommend a minimum spray interval of 5 to 7 days.

Populations are likely to continue rising as more food is available to the flies. Often it is not until we have experienced several hard frosts that we see populations start to decline. Harvest regularly and often to prevent the buildup of overripe fruit and remove all rotten or cull fruit from the field. Prune out excessive vegetative growth that provides shade and cover for the flies. This will also improve spray penetration.

For more information on identifying spotted wing drosophila and updates on populations around the state, visit our SWD blog.

Other IPM Web Pages

• Michigan State University
• Penn State University
• University of New Hampshire

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm, P.O. Box 179, 52 US Route 202, Monmouth, ME 04259, 207.933.2100

UMaine Extension Diagnostic Research Lab, Pest Management Unit, 17 Godfrey Drive, Orono, ME 04473, 1.800.287.0279

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