Spotted Wing Drosophila Update: September 3, 2021
SPOTTED WING DROSOPHILA UPDATE: 9/3/2021
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
Spotted wing drosophila catches in vinegar/yeast traps have reached the highest levels of the season this week. We are seeing significant increases in populations at nearly all sites just as fall raspberries and day neutral strawberries are coming into season. These high population levels increase the threat of larvae infesting the fruit, unless it is protected regularly and often. Some growers have moved to a three- to five-day spray interval to keep larvae out of fruit. A five-day to seven-day interval may still be adequate if you have not yet seen many flies or noticed infested fruit.
Populations may continue to increase as the recent tropical storm could have brought up more flies from the south, and as more ripe fruit becomes available. Remember that keeping the fields as free as possible from over ripe fruit and waste fruit on the ground can help reduce fly numbers. Harvest fruit regularly and often, and chill any fruit that is going to market down to 32-38 degrees Fahrenheit, to stop the development of any eggs or larvae that may be present.
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 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 8/15/21 | Spotted Wing Drosophila weekly trap catch 8/22/21 | Spotted Wing Drosophila weekly trap catch 8/29/21 |
|---|---|---|---|
| Wells | 256 | 472 | 736 |
| Limington | ** | ** | 664 |
| Limerick | 223* | 555 | |
| New Gloucester | 2384 | 170 | 269 |
| Bowdoinham | 912 | 1304 | 913 |
| Mechanic Falls | 328* | 288 | |
| Monmouth | 2304 | 1184 | 1824 |
| Wayne | 1648* | 3344 |
*Number represents 2 weeks of capture
**Trap damaged; no data
| 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