Spotted Wing Drosophila Update: August 13, 2021
SPOTTED WING DROSOPHILA UPDATE: AUGUST 13, 2021
Click on photos to enlarge
David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist, Phil Fanning, Assistant Professor of Agricultural Entomology, Christina Howard, Produce Safety Professional
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- SWD on Raspberry; photo by David Handley.
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- Drosophila Trap, photo by David Handley
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- SWD Larvae in Blackberry, photo by David Handley
Counts of spotted wing drosophila in vinegar/yeast traps continued to rise in most locations this week. Although the increase was not as dramatic as last week, these population levels will enhance the threat of larvae infesting the fruit, unless it is protected regularly and often. Growers with ripe or nearly ripe berry fruit should continue to protect their crops against infestation. A five to seven-day spray interval should be adequate for keeping larvae out of fruit. Use a seven-day interval if you’re not yet seeing any flies or noticing infested fruit, but tighten to a five-day schedule if you see flies around the fruit during harvest, or have found larvae in the fruit.
Spotted wing drosophila populations are very likely to continue increasing in the coming weeks as more flies are now present to lay eggs and more food is becoming available. Monitor the flies in the planting with traps, and check ripe fruit often for the presence of larvae. See our blog for information on making and placing traps, and a list of currently registered insecticides for SWD.
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 Office
P.O. Box 179 17 Godfrey Dr.
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 7/25/21 | Spotted Wing Drosophila weekly trap catch 8/1/21 | Spotted Wing Drosophila weekly trap catch 8/8/21 |
|---|---|---|---|
| Wells | 39 | 57 | 82 |
| Sanford | 12 | 18 | 110 |
| Limington | 97 | 472 | 183 |
| Limerick | 1 | 4 | 46 |
| New Gloucester | 176 | 2664 | |
| Bowdoinham | 121 | 472 | 600 |
| Mechanic Falls | 1 | 9 | 3 |
| Monmouth | 27 | 147 | 1504 |
| Wayne | 4 | 38 | 76 |
| Trade Name | IRAC Group | Days to Harvest Blueberry |
Days of Residual |
|---|---|---|---|
| Assail® | 4A | 1 | 5-7 |
| Mustang Max® | 3 | 1 | 7 |
| Bifenture® | 3 | 1 (3 raspberry) | 7 |
| Brigade® | 3 | 1 (3 raspberry) | 7 |
| Danitol® | 3 | 3 | 7 |
| Delegate® | 5 | 3 (1 raspberry) | 7 |
| Entrust®* | 5 | 3 (1 raspberry) | 3-5 |
| Exirel® | 28 | 3 (1 raspberry) | 5-7 |
| Imidan® | 1B | 3 (not for raspberry) | 5-7 |
| Malathion | 1B | 1 | 3-5 |
| PyGanic®* | 3A | 0 | 0 |
| Verdepryn ® | 28 | 1 | 5-7 |
*OMRI approved