Potential New Pest of Fruit – Spotted Wing Drosophila

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

By now, all should be aware of the newest insect pest present in the Mid-Atlantic Region, the Brown Marmorated Stink Bug. However, there is also a potential for another new pest in 2011, the Spotted Wing Drosophila. These flies can infest and cause a great deal of damage to ripening fruit, as opposed to the overripe and fallen fruit that are infested by most other Drosophila species. Females damage fruit by slicing through the skin with their knife-like ovipositor, and inserting eggs that develop into small white larvae. These cuts can also be a pathway for fungal pathogens, leading to greater reductions in fruit quality. Therefore, knowing that it is in the area and how to monitor it is important to avoid economic loss. This insect is a pest of most berry crops, cherries, grapes and other tree fruits, with a preference for softer-fleshed fruit. In areas where it has been detected, it is has become an important pest of cherries, raspberries, blackberries, blueberries, strawberries, grapes, peaches, and plums. So far it has been detected in California in 2008, in Florida and Oregon in 2009, and in Michigan, North Carolina and South Carolina in 2010. Although we do not have the resources to do an extensive monitoring program, we are currently trapping for it in one location in Delaware in 2011.

For more information on monitoring, identification and control of this insect pest, please check the following links:
http://www.ncipmc.org/alerts/drosophila.cfm
http://swd.hort.oregonstate.edu/