Spotted Wing Drosophila Alert: 8/6/2018

This announcement is also posted with color pictures on the Highmoor Farm Spotted Wing Drosophila web blog at, where you can subscribe to updates. Please keep us abreast of any email address changes. Thank you.


Spotted Wing Drosophila Alert:  8/6/2018


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


Captures of spotted wing drosophila (SWD) fruit flies in vinegar/yeast traps in raspberry and highbush blueberry plantings remained low in most locations, although at two sites ((Limington, Readfield) counts rose above threshold levels. (See table below.) The recent warm, wet weather will encourage SWD infestations, however, as it may lead to more rotten fruit in the field and increase ambient moisture levels. Growers should try to keep rotten fruit out of the field as much as possible and encourage dry conditions by pruning out excess growth, especially near the base of the plantings. Growers who have been catching flies in their traps for more than one week and have ripening fruit should put on a protectant spray.


We expect spotted wing drosophila populations to increase significantly in the coming weeks as more ripe and rotten fruit becomes available for the flies. Protective sprays should be applied if more than four spotted wing drosophila flies are caught in a trap, flies are caught consistently for more than one week, or any larvae are noticed in the fruit. Look for fruit flies hovering around fruit and symptoms of premature fruit decay.


For more information on identifying spotted wing drosophila and updates on populations around the state, visit our SWD blog at:


Other IPM Web Pages
Michigan State University:

Penn State University:

University of New Hampshire:


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


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 7/20/18 Spotted Wing  Drosophila weekly trap catch 7/27/18 Spotted Wing  Drosophila weekly trap catch 8/3/18
Wells 0
Sanford 13 3 0
Limington 1 1 12
Limerick 0 0 0
Buxton 3 5 0
Bowdoinham 1 1 2
Cape Elizabeth 1
Dresden 5 2 5
Freeport 0 0 0
Poland Spring 1 0 0
Mechanic Falls 0 0 0
Monmouth 3 0 2
Readfield 0 1 12
Wales 5 2
Farmington 8 1
Fayette 0 0 0
Wayne 0 0



Pam St. Peter ’78
Administrative Specialist II
University of Maine Cooperative Extension
Maine Crop Insurance Education Program
Highmoor Farm
P.O. Box 179/52 US Route 202
Monmouth, ME  04259
Tel. 207.933.2100 X100
Fax 207.933.4647