Spotted Wing Drosophila Alert and Berry Notes — October 6, 2023

October 6, 2023 Spotted Wing Drosophila
Blueberries on a bush
Blueberries; photo taken by Christina Howard, UMaine Extension

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

This will be the final issue of the Spotted Wing Drosophila Alert for the 2023 season.

Spotted wing drosophila counts declined substantially in all of our trapping locations this week. There has not yet been a frost, so we were not expecting to see lower populations this early. Most farms have ended harvest, but there are still some late raspberries and blueberries available to attract the flies. Fly populations are still high enough to threaten these fruit, so growers should continue to provide regular sprays until the crop is finished for the season.

A 5-7 day spray schedule is recommended 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.

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

Drosophila trap in a raspberry field
Drosophila trap in raspberries; photo taken by Christina Howard, UMaine Extension

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

Weekly Spotted Wing Drosophila Trap Captures
Town Spotted Wing Drosophila weekly trap catch 9/1/23 Spotted Wing Drosophila weekly trap catch 9/8/23 Spotted Wing Drosophila weekly trap catch 9/15/23 Spotted Wing Drosophila weekly trap catch 9/21/23 Spotted Wing Drosophila weekly trap catch 9/29/23 Spotted Wing Drosophila weekly trap catch 10/6/23
Wells 276 740 125 245 1,200 247
Limerick 65 175 64 442 51 5
New Gloucester 400 316 178 376 375 41
Mechanic Falls 1,029 500 65 224 157 4
Bowdoinham 158 270 296 291 1,596 274
Monmouth (unsprayed plot) 168 119 46 369 641 44
Wayne 1,012 696 98 2,040 1,602 11

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