Spotted Wing Drosophila Alert — August 8, 2025
David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist, Phil Fanning, Assistant Professor of Agricultural Entomology, Christina Howard, Maine New Farmers Project Manager
Spotted wing drosophila fruit fly numbers continue to increase at our trapping sites this week (see table below). Populations are over the recommended spray threshold (4/trap/week) at all sites. While the hot, dry conditions seem to be keeping populations from increasing at a fast pace, as we would normally expect to see now, any rain in the near future, and the increased presence of ripe and over ripe fruit will likely stimulate higher pressure soon. At present, a 7-day spray schedule on ripening fruit should be adequate to prevent infestation by larvae.
If you are growing raspberries, blackberries and/or blueberries, you should be managing spotted wing drosophila on any fruit that is presently ripening and/or being harvested to prevent infestation.
For more information on identifying spotted wing drosophila (SWD) and updates on populations around the state, visit our SWD blog.
Maine Specialty Potato Variety Showcase at Rogers Farm
When: Friday, Aug 29 from 12:30 – 3:00 PM
Where: Rogers Farm Forage and Crop Research Facility, 914 Bennoch Road, Old Town, ME 04468
Program description:
Join UMaine Extension Sustainable Agriculture Educator, Brett Johnson and UMaine Assistant Professor of Potato Breeding and Genetics, Mario Andrade, for a presentation covering results of the 2024 Organic Specialty Potato Variety Trial conducted at the Rogers Farm Forage and Crop Research Facility. Following the presentation attendees will have the opportunity to view potato varieties in the 2025 trial plots including new releases from the Maine Potato Breeding Program. Registration is required.
Findings should be of special interest to commercial farmers considering producing specialty potato products, commercial farmers currently producing specialty potato products, seed industry representatives, and new and beginning farmers exploring market opportunities.
For more information or to request a reasonable accommodation, contact Billiejo Pendleton; billiejo.pendleton@maine.edu.
Other IPM Web Pages
Michigan State University Spotted Wing Drosophila
Penn State University Spotted Wing Drosophila Overview
University of New Hampshire SWD Weekly IPM Reports
David T. Handley
Vegetable and Small Fruit Specialist
Highmoor Farm
P.O. Box 179
Monmouth, ME 04259
207.933.2100
UMaine Extension Diagnostic Research Lab
Pest Management Unit
17 Godfrey Drive
Orono, ME 04473
1.800.287.0279
| Town | SWD weekly trap catch 7/18/25 | SWD weekly trap catch 7/25/25 | SWD weekly trap catch 8/1/25 | SWD weekly trap catch 8/8/25 |
|---|---|---|---|---|
| Wells | 9 | 3 | 65 | 113 |
| Springvale | 46 | 6 | 17 | 22 |
| New Gloucester | 42 | 37 | 94 | 478 |
| Cape Elizabeth | 101 | 16 | 67 | 107 |
| Bowdoinham | 43 | 45 | 21 | 21 |
| Mechanic Falls | 1 | 0 | 0 | 14 |
| Monmouth | 3 | 2 | 37 | 145 |
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