Spotted Wing Drosophila Update – August 5, 2022
![Spotted Wing Drosophila on Raspberry](https://extension.umaine.edu/highmoor/wp-content/uploads/sites/48/2019/04/SWDRaspberry12c-DHandley-300x225.jpg)
Spotted Wing Drosophila Update – 8/5/2022
David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist, Phil Fanning, Assistant Professor of Agricultural Entomology
Fly counts are creeping upwards this week but have not yet begun the rapid rise we typically see starting about this time. Several sites, including Wells, Bowdoinham, New Gloucester, Monmouth, and Wells, were above the 6 fly threshold that is considered potentially damaging to ripening berry crops. At this level, growers should expect larvae to start appearing in the fruit unless protective sprays are applied (see table below).
![Spotted Wing Drosophila Larvain in Raspberry](https://extension.umaine.edu/highmoor/wp-content/uploads/sites/48/2015/10/SWDLarvae2012a-300x225.jpg)
Spotted wing drosophila populations are expected to build rapidly in the coming weeks, especially if we get more rain. Start protective sprays on any berries that have begun to ripen when more than six spotted wing drosophila flies are caught in a trap, or any larvae are noticed in the fruit. Look for fruit flies hovering around fruit and symptoms of premature fruit decay.
Keep berry fields clean of over-ripe and rotten fruit as much as possible. Rotten fruit on the plants or on the ground will greatly increase the number of fruit flies present, by providing them with food and egg-laying sites.
Other IPM Web Pages
Michigan State University: http://www.canr.msu.edu/ipm/invasive_species/spotted_wing_drosophila/
Penn State University: https://extension.psu.edu/spotted-wing-drosophila-part-1-overview-and-identification
University of New Hampshire: https://extension.unh.edu/resource/spotted-wing-drosophila-ipm-weekly-scouting-reports
David T. Handley
Vegetable and Small Fruit Specialist
Highmoor Farm Pest Management Office
P.O. Box 179 491 College Avenue
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 7/18/22 | Spotted Wing Drosophila weekly trap catch 7/28/22 | Spotted Wing Drosophila weekly trap catch 8/5/22 |
Wells | 0 | 11 | 17 |
Springvale | 0 | 0 | 1 |
Limerick | 0 | 3 | 3 |
New Gloucester | 4 | 11 | 18 |
Bowdoinham | 10 | 14 | 52 |
Mechanic Falls | 0 | 0 | 0 |
Monmouth | 3 | 11 | 11 |
Fayette | 0 | 0 | 0 |
Wayne | 0 | 0 | 2 |