USDA Awards $6.7 Million To Stifle Spotted Wing Drosophila

North Carolina State University has won a $6.7 million grant from the USDA to undertake research and grower education efforts aimed at better managing a major new pest that causes hundreds of millions of dollars in annual agricultural losses.

(Photo Credit: Elizabeth Beers, Washington State University)

(Photo Credit: Elizabeth Beers, Washington State University)

Under the four-year specialty crop grant from USDA’s National Institute for Food and Agriculture, N.C. State University scientists will join with researchers and Extension specialists from across the nation to conduct on-farm tests aimed at finding new ways of effectively dealing with spotted wing drosophila, a tiny fruit fly that’s been causing big problems since it was first detected in North America in 2008.


They’ll also develop tactics and tools for predicting risks from the pest, along with educational materials to help growers make the most economically and environmentally sound management decisions.

N.C. State’s collaborators in the effort are from Michigan State, Oregon State, Cornell, and Rutgers universities, as well as the universities of Maine; Notre Dame; Georgia; California, Davis; and California, Berkeley; and  USDA’s Agricultural Research Service.

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Hannah Burrack, an associate professor and Extension specialist at N.C. State University who is a member of American Fruit Grower® and Western Fruit Grower® magazines’ Editorial Advisory Board, is leading the grant-funded effort to develop better ways to manage spotted wing drosophila.

Others from NC State who are participating in the project are Max Scott of the Entomology Department, Zack Brown of the Agricultural and Resource Economics Department, Rhonda Conlon of Extension Information Technology, and Jean-Jacques Debois of the Southern Integrated Pest Management Center.

Burrack emphasized that spotted wing drosophila, (Drosophila suzukii), lays eggs in such valuable soft-skinned fruit as raspberries, blackberries, blueberries, strawberries, and cherries. The eggs develop into larvae, leaving the fruit unmarketable.

Marketers who buy fruit from growers to sell to grocery stores “have zero tolerance for spotted wing drosophila infestation in fruit,” Burrack said. “If they find a single larva in a fruit, the entire load from that grower will be rejected. Nationally, we estimate that these economic losses to growers on an annual basis are over $700 million a year.”

Hannah BurrackSWD has been recognized as a pest in Asian fruits since the 1930s. “In just seven short years, it’s gone from initial detection in California to global-range phenomenon,” Burrack said. “It’s found everywhere we grow the crops it feeds on in North America, it’s widely distributed in Europe, and it’s been found in South America. That’s a shocking rate of expansion for a pest organism.”

Right now, Burrack added, growers have found only two ways of dealing with the insect: They use insecticides, or they cut their growing season short.

“This is neither environmentally or economically sustainable,” she says. “We want to bring back Integrated Pest Management to berry and cherry cropping.”

In the U.S, insecticide use has grown in host crops by at least 30% in response to spotted wing drosophila’s threat, she said.

“Some berry crops rarely received any insecticide applications during harvest, and now they may receive at least weekly insecticide treatments,” she said.

Now, growers are forced to spray when the fruit changes color, as that is when SWD attacks, she said.

Still, even the best insecticide treatments may be rendered ineffective under adverse environmental conditions, such as rainy periods, she added. Not only that, SWD is such a prolific reproducer that scientists are concerned the pest may develop resistance to the currently used treatments.

These are among the reasons that Burrack and others involved in the grant-funded project want to help growers reduce their reliance on insecticides for managing spotted wing drosophila.

“The economic impact is important. Berry crops and cherries are worth more than $4.37 billion annually in the United States and are grown on close to 42,000 farms. These crops are high value per acre, and for this reason, they are particularly important components of local-food systems,” she said.

“Our biggest goal is to have things return to a management program that is sustainable both economically and environmentally for our growers, where all the tools effective against spotted wing drosophila are being utilized, and pesticide use occurs only when absolutely necessary.”

Burrack added that postharvest management is an important component of the research. For example: “Sophisticated optical sorting technology is used now, but how can we better use it?”


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Avatar for Tom Stevenson Tom Stevenson says:

Why on earth wasn’t this scourge quarantined in California when there was at least a chance of containing it? USDA refused to quarantine.

Avatar for forbes morrell forbes morrell says:

Is there going to be a news letter on this subject and if so, how do we get continuing info?

Avatar for Francis Bartolomeo Francis Bartolomeo says:

I had the swd pest for the first time this year. From which I determined we need more tools to do the job. Such as research to find preditors, diseases, systemic pesticides, additional chemicals and intervention by the government such as the state of Florida and California and how they are combating simular pests.If nothing is done we will lose the few chemicals that is available now byoveruse. The cycle from egg to adult is only 5 days .At times spraying has to be done on a 1 or 2 day schedule

Avatar for Ron Buchanan Ron Buchanan says:

This year we did not see SWD in traps but they were in late red raspberries. I agree with Bartolomeo: spraying is as much a problem as the SWD. Re-entry and days before harvest adds to the problem as fruit. continues to ripen and over-ripen accentuating the losses. USDA has waited until a problem has become a stifling disaster.

Never mind managing this fly, we need to find a way to kill it. My husband and I had two 300 ft. rows of raspberries. We got the fly in our fall crop. I don’t think the 90 degree heat helped. We cut down one row, because we could not manage two. We picked all of the ripe berries for weeks and crushed them with our shoes, trying to get a handle on the disaster. We sprayed our compost pile because they were breeding there. We also cleaned up any dropped cherry tomatoes in the greenhouse. The fly loves the split tomatoes. We did all we could to stop the fly from laying eggs. My husband wants to cut down the wild grapes on the stone wall by the raspberry field next year. Friends that manage a apple orchard, abandoned their raspberries when they found the fly, leaving them to just increase in numbers. I think that was wrong. My husband sprayed once a week, but that was not enough. It got to the point that if we say a fly, he sprayed it. Not really ! He did spray once a day, or every two days with pyrethrum. He also had lights on his tractor so when he sprayed it was at night, to protect the bees. We had thought about planting a couple of blueberry rows, but whats the point. Until these guys figure something out, it will be to much work, or cost to much for the small farmers. I am 69 and my husband is 78. This past year was really hard physically and emotionally. Our beautiful raspberries were a mess, and I am worried about our neighbor that has a big blueberry field that he was going to pick for the first time next summer. I told him the news so he can be ready to do battle with the red eyed monster next summer.

Avatar for Jim Maryinuk Jim Maryinuk says:

Please keep me in the mix of the study results. I have been trying different techniques in my raspberry/ BlackBerry high tunnels. I don’t like to spray if I can use other methods of reducing or eliminating this rascal.

Avatar for Bruce Carson Bruce Carson says:

Jim, have you tried screening? New York growers have been refining a combination of exclusion screening and fixed spray systems which allow should allow for more precise and effective control. Contact the New York State Berry Growers Association for more details.