Spotted Wing Drosophila Alert: September 11, 2017

Spotted Wing Drosophila Emerging from Fall Raspberries
SWD Emerging from Fall Raspberries; photo by James Dill

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

Our trap captures for spotted wing drosophila did not change significantly in most locations last week, meaning that populations are generally well over the tolerance level to prevent infestation of any soft fruit remaining in the fields. (See table below.) Growers with any susceptible ripening fruit need to continue protecting their crop against larval infestation. Only regular, consistent spray coverage will prevent fruit infestation. At this time, we continue to recommend a minimum spray interval of 5 to 7 days.

We do not expect populations to start to decline until the flies are exposed to several hard frosts. There is a possibility that any tropical storm fronts moving into the region could actually cause a significant increase in drosophila numbers. Keep harvesting ripe fruit regularly and remove all rotten or cull fruit from the field.

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

Other IPM Web Pages

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

Where brand names or company names are used it is for the reader’s information. No endorsement is implied nor is any discrimination intended against other products with similar ingredients. Always consult product labels for rates, application instructions and safety precautions. Users of these products assume all associated risks.

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Town Spotted Wing Drosophila weekly trap catch
Spotted Wing Drosophila weekly trap catch
Spotted Wing Drosophila weekly trap catch
Wells 387 1256 273
Sanford 93 143
Limington 842 428 568
Limerick 217 237 326
Cape Elizabeth 4320 2968
New Gloucester 603 272
Bowdoinham 925 1448 449
Dresden 104 103 666
Freeport 40 56
Poland Spring 304 597 807
Mechanic Falls 16 65 77
Monmouth 415 681 434
Wales 1816 (2 weeks) 642 122
Farmington 1048 1552 1728