Skip Navigation
Return to Layout View | Home | A-Z Directory | my UMaine | MaineStreet | Campus Map | Calendar
Follow UMaine on Twitter | Join UMaine on Facebook | Watch UMaine on YouTube | Admissions | Parents & Family | Apply | Give Now | Emergency

Cooperative Extension at Highmoor Farm

Site Navigation:

Fruit Growers Alert 9/30/13: Spotted Wing Drosophila Counts Remain at High Levels

Fruit Growers Alert – September 30, 2013

For full page print version, please see link at the bottom. Click on photos to enlarge.


We continue to capture spotted wing drosophila flies at all of our monitoring sites from southern, mid-state and coastal Maine. While counts have dropped in some locations over the past week, levels are still high enough to infest any unprotected berries still remaining in the field. Highest counts have been at the coastal sites and lowest counts have been in the more northern and western sites. Our experience has shown that the flies will survive through repeated frosts and continue to infest fruit well into the fall. Therefore, any farms that still have late ripening raspberries, blackberries, blueberries, grapes or day neutral strawberries should continue to protect their crops with an approved insecticide. In some locations a 7-day spray interval may be adequate to prevent infestation, but areas with high fly populations may still require a 4 to 5-day spray schedule.

Recommended insecticide products that provide good control of drosophila on berries include Delegate®, Brigade®, Bifenture®, Danitol®, Mustang Max®, malathion and Assail®. Effectiveness of these products can range from three to seven days.  Please check product labels for rates, post-harvest intervals and safety precautions.

Four Rules for Managing Spotted Wing Drosophila:

  1. Spray ripening fruit regularly with an approved insecticide (every 5-7 days).
  2. Harvest crop frequently and regularly; remove all ripe and rotten fruit from the field.
  3. Chill all harvested fruit immediately to as close to 33º F as soon as possible; hold in refrigeration until ready to sell.
  4. Open up the planting through pruning and spacing to improve light and air penetration and reduce moisture and humidity within the plant canopy.

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

IPM Web Pages:

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.

Image Description: Print Friendly

Image Description: Spotted Wing Drosophila Larva in Blackberry

Image Description: Spotted Wing Drosophila Maggot in Raspberry


University of Maine Cooperative Extension

Contact Information

Cooperative Extension at Highmoor Farm
52 U.S. Route 202
Monmouth, Maine 04259-0179
Phone: 207.933.2100
The University of Maine
Orono, Maine 04469
A Member of the University of Maine System