Spotted Wing Drosophila Alert and Berry Notes — September 13, 2024

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:

Fly counts in our vinegar/yeast traps this week were lower in all locations, likely due to cooler night and morning temperatures (see table below). Counts were still high enough to infest late ripening fall raspberries, blackberries and blueberries so we strongly recommend continuing protective sprays on all ripening berries and soft fruit crops to protect against infestation. The presence of any larvae in ripening fruit should also initiate a regular spray program if you are not using traps to monitor the flies. This week counts ranged from 12 to 988 in our traps, indicating that ripening fruit still require regular and frequent protection to prevent infestation. A 5- to 7-day spray interval should minimize fruit infestation, depending on the level of pest pressure in a given field.

For more information on identifying spotted wing drosophila (SWD) and updates on populations around the state, visit our SWD blog.

grape photo for landing page image link for resources by cropBerry Notes:

Here’s an update on Grape Berry Moth from Karen Coluzzi, State Pest Survey Coordinator, Division of Animal and Plant Health, Maine Department of Agriculture, Conservation & Forestry:

I just wanted to inform you that we had a confirmed positive detection this year of grape berry moth (Paralobesia viteana) at one of the vineyards. Although a native insect, it is considered one of the most serious pests of cultivated grape in North America. Grape berry moth has 2-3 generations per year depending on annual weather patterns. This time of year, the 2nd generation caterpillars have likely concluded feeding in the grape berries. They will overwinter as pupae.

Here are a number of fact sheets about grape berry moth:

Ohio State University
University of Maryland Extension
University of Connecticut

If you suspect you have grape berry moth, please reach out to get it confirmed.

More information on managing Grape Berry Moth can be found in the New England Small Fruit Management Guide.

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

Weekly Spotted Wing Drosophila (SWD) Trap Captures

Town SWD weekly trap catch 8/9/24 SWD weekly trap catch 8/16/24 SWD weekly trap catch 8/23/24 SWD weekly trap catch 8/29/24 SWD weekly trap catch 9/6/24 SWD weekly trap catch 9/13/24
Wells 287 197 1264 595 2,160 988
Sanford 56 117 592 191
Limington 11 396 189 88 154 12
Bowdoinham 48 352 492 546 235 204
New Gloucester 24 305 544 164 722 153
Mechanic Falls 26 134 680 72 674 23
Monmouth 46 456 232 81 95 22

 

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

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