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Spotted Wing Drosophila Alert: September 25, 2018

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

Insects in Spotted Wing Drosophila Trap

Insects in Spotted Wing Drosophila Trap, Male SWD Circled, photo by Kaytlin Woodman

Spotted Wing Drosophila Emerging from Fall Raspberries

SWD Emerging from Fall Raspberries, photo by James Dill

We regret that we have not been able to keep up regular weekly maintenance of all of our spotted wing drosophila (SWD) traps over the past few weeks, due to a shortage of help and conflicting schedules. We hope to keep the traps up for one more week, as frost is now bringing an end to the season for most parts of the state. In general, drosophila captures have been high enough to warrant regular sprays on all berry crops that are still being harvested, e.g. fall raspberries and day-neutral strawberries. While populations have been variable from site to site, ranging from the tens to the thousands, they have been high enough to result in rapid infestation of fruit if left untreated. (See table below.) A 5 to 7-day spray schedule on all ripening fruit should be adequate for most plantings. Make sure your sprayer is providing good coverage of the plant surface, especially in the lower part of the canopy, and try to keep any overripe or rotten fruit out of the field. Weather predictions suggest that conditions will continue to be good for SWD to infesting any ripening fruit, until either the fruit is gone, or we have experienced several hard frosts.

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                         UMaine Extension Diagnostic Research Lab
P.O. Box 179                               Pest Management Unit
52 U.S. Route 202                     17 Godfrey Drive
Monmouth, ME 04259             Orono, ME 04473
207.933.2100                             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.

The University of Maine is an equal opportunity/affirmative action institution.

Town Spotted Wing  Drosophila weekly trap catch 8/17/18 Spotted Wing  Drosophila weekly trap catch 8/24/18 Spotted Wing  Drosophila weekly trap catch 8/31/18 Spotted Wing  Drosophila weekly trap catch 9/7/18
Wells 5 12 48 114
Sanford 7
Limington 23 180 1600
Limerick 1 108 1680
Buxton 58
Bowdoinham 152 15 74 68
Cape Elizabeth 1441 353 312 197
Dresden 10 440
Freeport 7 173
Poland Spring 7 10 190 325
Mechanic Falls 2 13 66
Monmouth 74 469 1336 861
Readfield 51 140
Farmington 3 154 296
Fayette 0
Wales 4616 123 1512 328
Wayne 1 8 32



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