Figure 1. Spotted Wing Drosophila fruit fly. (Source: Jim Kalisch)
 

October 11, 2013

The Spotted Wing Drosophila (Figure 1), a newly introduced fruit fly from Asia, has now been confirmed in multiple Nebraska counties. First detected in California in 2008, it was first found in the north central region in Michigan in 2010 and is now broadly distributed across many states in the U.S.

We detected it for the first time in multiple counties in Nebraska in 2013 (Figure 2). We have not sampled all Nebraska counties and it may be present in other counties not shown on this map. It has been detected by using adult traps, as well from samples collected of adults and larvae in the following sites: blackberries, raspberries, grapes, Aronia (chokeberry) and urban vegetable gardens. In other states it has primarily been a pest of small fruits such as raspberry, blackberry, and similar small fruits. It is less commonly a pest of grapes and orchard fruits.

 

Figure 2. Distribution of Spotted Wing Drosophila in Nebraska 2013. (Source: Jim Kalisch)

Unlike native Drosophila fruit flies, which normally feed on damaged or rotting fruit, the Spotted Wing Drosophila adult female is capable of infesting undamaged small fruits, due to a sharp, serrated ovipositor, which allows it to penetrate the skin of small fruits and then insert its eggs. Spotted Wing Drosophila males have a noticeable black spot on the tip of each forewing, unlike other Drosophila species.

After UNL Extension faculty made the initial detections in Nebraska this summer, USDA-APHIS and UNL Extension continued surveying. We will provide an update on distribution later this year as well as suggestions for management of this pest in 2014.

Additional information about Spotted Wing Drosophila is available at:

• Regional Pest Alert, North Central Region Integrated Crop Management
• Fact sheets and information, Michigan State University

Bob Wright
Extension Entomologist
James Kalisch
Extension Associate-Insect Diagnostician