FARMINGTON — An informational meeting on the Spotted Wing Drosophila, a potentially serious new pest for Maine berry growers, is being offered at 6 p.m. Wednesday, Feb. 13, in the Farmington Municipal Building's downstairs conference room.
David Handley, vegetable and small fruit specialist for University of Maine Cooperative Extension's Highmoor Farm in Monmouth, and James Dill, pest management, will provide information on the new pest. The session is co-sponsored by the Franklin County Soil and Water Conservation District and the Franklin County Farm Bureau.
The Spotted Wing Drosophila (Drosophila suzukii) is a concern for growers of raspberries, blueberries and day-neutral strawberries, as well as many other soft fruits.
The insect is a small fruit fly, similar to the type that flies around over ripe bananas. However, this species lays its eggs in fruit before it ripens, resulting in fruit that is contaminated with small white larvae, just as it is ready to pick. As a result, the fruit quickly rots and has no shelf life.
The insect has come into the United States from northern Asia. It caused problems for many berry crops along the East Coast in 2011. It can complete a generation in under two weeks, with each adult female laying hundreds of eggs. Millions of flies can be present soon after just a few find their way into a field.
This makes them very difficult to control, and frequently repeated insecticide sprays — up to five times per week — may be needed to prevent infestations once the insect is in a field.
Spotted Wing Drosophila flies were captured for the first time in Maine in the fall of 2011. Based on crop damage experienced by southern growers in 2010 and 2011, fruit specialists and pest management knew this insect posed a serious threat to most of the berry crops grown here.
As part of the University of Maine Cooperative Extension Pest Management Program, Drosophila traps were set up in berry fields around the southern, central and coastal regions of the state. The first Spotted Wing Drosophila were caught in Limington on July 13. By Aug. 13, flies had been captured at all of the monitoring locations. During the same week, traps in wild blueberry fields in Hancock and Washington counties were also catching the flies.
Workshop organizers say growers and gardeners need to learn about this pest and develop strategies to manage it in their crops, because it appears it will be a problem in Maine for the foreseeable future.