Spotted Wing Drosophila Repellent Discovered

Spotted wing drosophila (Drosophila suzukii) is an invasive fly that feeds on soft-skinned fruits such as blueberries, blackberries, raspberries, strawberries, cherries, and others.  It was first detected in California in 2008 and has since spread to many states throughout the U.S. While flies are normally attracted to over-ripe fruit, SWD will lay its eggs in the flesh of ripening fruit and the larvae will hatch and consume the fruit through its development into an adult.

Spotted wing drosophila (Drosophila suzukii) adult on raspberry by Hannah Burrack, North Carolina State University, Bugwood.org

Researchers at the University of California, Riverside found that a chemical produced naturally by fruits, Butyl anthranilate (BA), acts as a repellent for the fly.  BA is only produced in small amounts by fruit, by applying a 2.5% solution of BA to blueberries the researchers noted a substantial decrease in the number of larvae and pupae emerging from the fruit.  Nearly complete protection of the fruit was observed at a 10% solution of BA. This means that not only does BA reduce the amount of damage to fruit, but it also reduces the overall population by dissuading SWD from laying eggs.  BA is a commonly used flavor and fragrance ingredient and is generally recognized as safe by the American Food and Drug Administration (FDA). This chemical could serve as a safe and affordable option for fruit growers in place of other insecticides.

Source Article: Safe repellents that protect fruit from spotted wing Drosophila found
Spotted wing drosophila images: Drosophila suzukii
Spotted wing drosophila BugwoodWiki article: Drosophila suzukii
Spotted wing drosophila distribution map: Drosophila suzukii