Invasive flies attacking cherries earlier, researchers say

Jul 21, 2016

Researchers Nikki Rothwell (left) and Emily Pochubay examine spotted wing drosophila collected in local cherry orchards.
Credit NORTHWEST MICHIGAN HORTICULTURE RESEARCH CENTER

The tart cherry harvest has begun in northern Michigan. The cherry crop is large this year, but growers are dealing with rising numbers of spotted wing drosophila as they harvest.

Drosophila is a tiny insect that originally came from Asia. The bugs have found a home in Michigan in recent years, and their numbers have been growing.

Nikki Rothwell is coordinator of the Northwest Michigan Horticulture Research Center. She’s been studying spotted wing drosophila.

Jim Nugent says growers are spraying a lot more this year.

“It has significantly raised the cost of production for us this year," says Nugent. "If they find worms in the fruit, [it's] not acceptable to go to the market.”

Rothwell says chemical sprays work on drosophila, but spraying is expensive.

“We’re at the economic breaking point," says Rothwell. "If this insect is going to come out earlier, we’re going to have to put out more sprays earlier. So we have to figure out how we are going to solve this problem not through spraying, but are there ways that we can look at basic science or the life cycle of that pest.”

Rothwell says scientists in Asia – where drosophila originated – are experimenting with different predators that eat the insects.