The science behind the fight against invasive fruit flies in the Bay Area

This summer, a small number of invasive Mediterranean fruit flies were detected in San Jose . In response, the state started doing something that might seem strange: releasing millions more fruit flies out of airplanes every week to drift down upon the South Bay. (Close your mouth when looking up — kidding!)

But these flies are different. They’re males that have been exposed to radiation to make them sterile. They breed with female flies, but no viable eggs result – thus, the invasion is gradually eradicated. It’s a biological-control strategy that’s been used with success over the years in Southern California, as well as states like Oregon, Florida and Louisiana.

Jason Leathers is the branch chief for Pest Detection/Emergency Projects at the California Department of Food and A