Invasive pest threatens blueberries
November 30, 2012

LANSING -- It's the bug to keep your eyes open for -- if you can even see it.

Measuring at less than one-sixteenth of an inch, the spotted wing drosophila is taking a tough toll on next year's blueberry season.

The tiny insect was first spotted in the state in 2010 and has been plaguing farmers ever since, said Robert Tritten, district fruit educator for Michigan State University Extension in Genesee County.

"This is an invasive pest that comes from some other part of the world and it moves like we do as nomads," Tritten said.

Tritten said the insect arrived like many other invasive species -- through the importation of fruits and vegetables.

"Many farmers originally thought that the insect is your normal fruit fly, but there is a major difference," he said. "This bug can lay eggs in a soft-sided fruit and it will end up having worms or larvae in it once the fruit ripens."

Blueberries are a $101.8 million-a-year crop in Michigan. The state is the nation's largest source of commercial blueberries.

John Van Voorhees of Pleasant Hill Farm in Fennville says he saw a few of the pests toward the end of the last berry season.

"Luckily I didn't have any problem until we were about done harvesting," he said. "We are anticipating a higher number this year of the spotted wing drosophila around harvest time and we are going to spray insecticides more frequently if we can."

Tritten plans to help growers get ready for the problems before they begin.

"We are going to help them identify it, control it and manage it so the insect doesn't hurt their entire crop."

Tritten and other MSU Extension experts have created a emergency response team to test multiple strategies, but as of now, insecticides seem to be the best choice.

"We hope to find a possibility of a predator that will eat these insects or a possible trap, but we are still researching and figuring out what we can do," he said. "Another idea that we have thought of is putting nets over the berry bushes so that the insects cannot reach them."

Preliminary estimates show that in 2012, the spotted wing drosophila will cost Michigan growers $27 million.

Lee Makielski of Makielski Berry Farm in Ypsilanti said that the insect could force some farms to close.

"This insect is going to cause a rise in price for berries, but if we cannot get it under control it could force us to go out of business," he said.

But the spotted wing drosophila isn't going to disappear, Tritten warned.

"This isn't the type of insect we can just get rid of. It will be years upon years before it can be eradicated," he said. "As for now, we can just deal with it and try to manage with it here."