Be on the lookout for the Spotted Wing Drosophila!
According to a recent press release put out by the University of Illinois Extension an invasive pest that is relatively new to Illinois, the Spotted Wing Drosophila, has been found again this year in various locations in Illinois. Last fall samples were found in Peoria County and according to University of Illinois Extension Entomologist Dr. Rick Weinzierl, “It likely is present in most, if not all, of the counties in Illinois.”
The Spotted Wing Drosophila is a pest that will attack thinned skinned fruits including cherries, blueberries, grapes, nectarines, pears, plums, peaches, raspberries, and strawberries. They are also a moderate risk to tomatoes. The insects will lay its eggs into ripening fruit before fruit is ready for harvest. Infested fruits are destroyed due to larval feeding and subsequent rot.
The adult Spotted Wing Drosophila is tan with red eyes and is tiny, 2-3 millimeter long. Males have dark spots on their wings. Adults live up to 2 weeks, and females can lay up to 300 eggs. Development from egg to adult can occur in as little as eight days, and 10 or more generations may occur within a season.
The insect is a somewhat new pest arriving in North America as late as 2008. According to Wikipedia:
Drosophila suzukii, commonly called the spotted-wing drosophila, is a vinegar fly—closely related to Drosophila melanogaster (the common vinegar fly). Native to southeast Asia, D. suzukii was first described in 1931 by Matsumura. Observed in Japan as early as 1916 by T. Kanzawa, D. suzukii was widely observed throughout parts of Japan, Korea, and China by the early 1930s. By the 1980s, the “fruit fly” with the spotted wings was seen in Hawaii. It first appeared in North America in central California in August 2008 and is now widespread throughout California’s coastal counties, western Oregon, western Washington, and parts of British Columbia and Florida. During the summer of 2010 the fly was discovered for the first time in South Carolina, North Carolina, Louisiana, and Utah. In fall 2010 the fly was also discovered in Michigan and Wisconsin. The pest has also been found in Europe, including the countries of Italy, France, and Spain.
There was a $500 million loss due to pest damage in 2008 which was the first year the Spotted Wing Drosophila was observed in California. This is an indication of the potential damage the pest can cause after introduction to a new location. Economic losses have now been reported across North America and in Europe as the fly has spread to new areas.
This year’s samples in Illinois were found in traps placed in raspberries at the University of Illinois Research Farm near Urbana. Infested fruit was also found south of Springfield. To avoid finding the small white maggots of this pest in your crops it is suggested that you remove and destroy overripe fruit and keep fruit harvested.
To monitor presence of the adults a simple trap can be made out of a clear plastic cup with numerous small holes and a plastic wrap lid and hung in the shade near raspberries. Apple cider vinegar is used as bait in the bottom of the cup and this will keep the flies trapped until they can be identified.
Further information can be found at the following sites: