Spotted Wing Drosophila

The spotted wing drosophila is a new insect that enjoys fresh fruit as much as you do.

Amy Dreves is a research and extension entomologist at Oregon State University. She says the bug is a type of fruit fly that was discovered in California in 2008. Since then, it's spread to nearly every state.

The spotted wing drosophila likes to dine on strawberries, cherries, raspberries, blackberries, blueberries, and some ornamental fruits.

"When the crop becomes ripe, they seem to hone in," says Dreves. "And as the fruit ripens, the yeasts on the outside of these fruits start increasing and they love yeast. The female needs to lay eggs. She saws into the fruit, and she lays her one-to-three eggs."

You might see a speck on the fruit, which indicates where the female laid the eggs. When the eggs hatch, the larvae feed inside, which causes one side of the berry to soften and collapse. Dreves says unless the berry has rotted, it's still perfectly safe to eat. But most people would rather not eat insect-infested fruit.

One of the keys for control is knowing when the fly is about to strike.

"There's a lot of great research out there in monitoring," says Dreves. "Traps that actually can detect the presence of the fly itself in the field. And good traps, we found they like the colors red and yellow. We also have been studying baits. There are lures being developed to put into traps."

There are several registered chemicals that are effective for control. Sanitation is also a big tool in keeping insect numbers down. It's very important that growers harvest their fruit in a timely manner and clean up any that falls to the ground or is left hanging on the plant.