Spotted Wing Drosophila Update: August 30, 2019

Insects in Spotted Wing Drosophila Trap
Insects in Spotted Wing Drosophila Trap, Male SWD Circled, photo by Kaytlin Woodman


Click on photo to enlarge.

David Handley, Vegetable and Small Fruit Specialist; James Dill, Pest Management Specialist; Frank Drummond, Professor of Insect Ecology/Entomology; Christina Howard, Produce Safety Professional

Spotted wing drosophila fruit fly numbers continue to rise at most of the berry farm locations we’re monitoring. All sites are now over the recommended spray threshold to prevent fruit from becoming infested with larvae. Susceptible crops, including raspberries, blackberries, blueberries and fall strawberries should remain on a protective spray schedule if ripening fruit is present. A seven-day spray interval should be adequate in most situations, but a five-day interval may become necessary if larvae continue to be present in fruit with the seven-day interval. Be sure to read and follow all pesticide product labels carefully, especially in regards to days to harvest restrictions and the number of applications allowed per growing season. Rotate products used regularly to prevent the possible development of resistance.

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
Penn State University
University of New Hampshire

David T. Handley
Vegetable and Small Fruit Specialist

Highmoor Farm                      UMaine Extension Diagnostic Research Lab
P.O. Box 179                           Pest Management Unit
52 U.S. Route 202                  17 Godfrey Drive
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 8/16/19 Spotted Wing Drosophila weekly trap catch 8/23/19 Spotted Wing Drosophila weekly trap catch 8/30/19
Sanford 143 968 3616
Limington 226 69 40
Limerick 4 6 51
Cape Elizabeth 318 1408 520
Dresden 15 52 271
Buxton 352 310 181
Bowdoinham 108 576
Poland Spring 61 122 377
Mechanic Falls 0 10 28
Monmouth* 389
Fayette 2 12 43
Freeport 7 93 264
Farmington 2 9
Readfield 97 345
Wayne 12 9
Wells 5 6 13

*unsprayed planting