Gardeners who grow fruit, especially small fruits such as cherries, blueberries, blackberries, strawberries and raspberries, might be seeing a new invasive pest this summer. According to Penn State researchers the African fig fly (Zaprionus indianus Gupta) has been found in Adams, Clearfield Dauphin, and York Counties.
The African fig fly entered the country through ports in Florida 8 years ago and is rapidly spreading across the country. Because it lacks a sharp ovipositor, common in fruit flies, it mostly attacks soft, overripe or damaged fruit. The concern in Pennsylvania is for the grape crop. The Department of Agriculture began finding this fly in tomato and grape pest survey traps in early October of 2012. Shortly thereafter, the flies began to appear in apple cider traps set out to monitor spotted wing Drosophila at the Penn State Fruit Research and Extension Center in Biglerville.
Ordinarily tropical pests, such as this African native, do not survive our winters but this one may be an exception. Records of fruit fly surveys in Adams county indicate that it managed to not only survive the winter of 2011-2012, a relatively mild winter, but also came through the winter of 2010-2011 a more typical winter.
Slightly larger and lighter in color than a typical fruit fly the African fig fly is easily identified by 2 silver stripes along the back. These are outlined by broader black stripes. These stripes have earned the fly the nickname of “Speed Racer Fly”. Keep this in mind should you find something new among your strawberries this summer.