SPOTTED WING DROSOPHILA UPDATE: August 21, 2020
SPOTTED WING DROSOPHILA UPDATE: August 21, 2020
Click on photos to enlarge.
David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist, Christina Howard, Produce Safety Professional
Spotted wing drosophila (SWD) fruit fly numbers continued to increase at nearly all of our monitoring sites this week. At this time of year, the abundance of ripe fruit available can stimulate SWD populations to increase rapidly. Most trap counts are at their highest levels of the season, meaning there is high potential of infestation to any ripening berries remaining (see table below). A five to seven-day spray interval is recommended for ripening berry fields to prevent infestation of larvae in the fruit. This will probably be required for the rest of the harvest season.
Remember that keeping the field free of waste fruit can reduce drosophila numbers. All fruit should be chilled to 34 degrees F (or as close as possible) immediately after harvest to halt development of any eggs or larvae. Rotate pesticide products used regularly to prevent the possible development of resistance. Current information on registered pesticides for managing SWD is available in the New England Small Fruit Management Guide. The online version is free and can be viewed here
For more information on identifying spotted wing drosophila (SWD) and updates on populations around the state, visit our SWD blog
Other IPM Web Pages
Michigan State University:
David T. Handley
Vegetable and Small Fruit Specialist
Highmoor Farm Pest Management Unit
P.O. Box 179 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 8/7/20 | Spotted Wing Drosophila weekly trap catch 8/14/20 | Spotted Wing Drosophila weekly trap catch 8/21/20 |
|---|---|---|---|
| Wells | 4 | 36 | 107 |
| Sanford | 135 | 42 | 424 |
| Limington | 893 | 1188 | 1480 |
| Limerick | 21 | 114 | 594 |
| Cape Elizabeth | 31 | 101 | 3216 |
| Bowdoinham | 1021 | 2440 | 2920 |
| Mechanic Falls | 11 | 95 | 351 |
| Monmouth | 61 | 2944 | 2480 |
| Wayne | 661 | No data | 920 |