Spotted Wing Drosophila Alert and Berry Notes — September 8, 2023
David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist, Phil Fanning, Assistant Professor of Agricultural Entomology, Christina Howard, Maine New Farmer Project Manager
Spotted wing drosophila trap counts have remained relatively steady for several weeks, which is unusual for this late in the season. Past experience has typically shown significant increases in populations late in the season as more food becomes available and more flies come north from southern regions. It may be that there simply isn’t as much food (rotten berries) available yet this season to support the anticipated population explosion. However, numbers are high enough to pose a significant threat to any ripe or ripening berries remaining in the field, so growers should maintain a regular, frequent spray interval to prevent larvae from infesting their fruit.
At this point, a 5-7 day schedule of sprays may be required to minimize fruit infestation in fields.
For more information on identifying spotted wing drosophila (SWD) and updates on populations around the state, visit our SWD blog.
David T. Handley
Vegetable and Small Fruit Specialist
P.O. Box 179
Monmouth, ME 04259
UMaine Extension Diagnostic Research Lab
Pest Management Unit
17 Godfrey Drive
Orono, ME 04473
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|Town||Spotted Wing Drosophila weekly trap catch 8/4/23||Spotted Wing Drosophila weekly trap catch 8/11/23||Spotted Wing Drosophila trap catch average for 8/14/23 – 8/25/2023||Spotted Wing Drosophila weekly trap catch 9/1/23||Spotted Wing Drosophila weekly trap catch 9/8/23|
|Monmouth (unsprayed plot)||43||114||1,408||168||119|