Collaborators in Region Join Chorus against Spotted Wing Drosophila

Cacophony: SWD damages raspberry. Source: Hannah Burrack, North Carolina State University, Bugwood.org

Researchers and educators, working together online and in the field, are confronting an invasive species that has changed the tune for Northeastern fruit growers: the spotted wing drosophila (SWD).

SWD is a small “fruit fly” that has upset crop production across North America as it has moved eastward since its discovery in California in 2008. The three-millimeter adult female SWD saws through soft-fleshed fruit as it approaches its peak of ripeness, laying eggs in raspberries, blueberries, blackberries, strawberries, grapes, and late-season peaches, all valuable crops in the Northeast.

In 2011–12, the Northeastern IPM Center awarded about $210,000 in funds for SWD research in the region, including a Regional IPM Competitive Grant of just over $160,000 to Richard Cowles, a scientist at the Connecticut Agricultural Experiment Station, for research on sustainable management of SWD. The Center also funded three Urgent IPM projects in the fall of 2011 totaling just under $30,000.

Glen Koehler, an associate scientist at the University of Maine, received one of those grants. He recalled that in August 2011, “Fall raspberry growers in Connecticut and New Hampshire got clobbered. More than one grower told me that this pest was driving them out of business.”

Orchestrating a Response

Going into 2012, Koehler knew that New England fruit growers faced an imminent threat and needed information on whether the problem would reoccur. If it did, growers would need to know where and when SWD was spreading. “My plan was to get everyone working on the same page. I knew we could be more efficient and get a better handle on the situation if we collaborated on methods and combined our observations.”

As part of that collaboration, Koehler worked with Cowles to organize a meeting in March 2012 of 40 extension and research staff from New England and New York to learn about SWD biology, monitoring, and management. Cowles devised the bait and provided biological insight that Koehler used to design a simple, inexpensive, and effective New England-wide SWD survey protocol.

Showtime

The grant funds made it possible to build and distribute over 1,000 traps and enough bait formula for season-long trapping at 244 different sites, with multiple traps per site. Survey leaders in each of the cooperating states—Jim Dill, David Handley, and Frank Drummond in Maine; Heather Faubert in Rhode Island; Alan Eaton in New Hampshire; Sonia Schloemann in Massachusetts; Mary Conklin in Connecticut; and Ann Hazelrigg in Vermont—provided labor and vehicles for weekly visits to collect trap contents, count SWD, and record observations. Joseph LaForest, University of Georgia, and Hannah Burrack, North Carolina State University, provided access to a computer mapping system tailored to display the New England information.

“It is important for us to work together,” Koehler said. “We received just under $10,000 from the Northeastern IPM Center, and we leveraged that with extension and research programs across six states to prevent roughly $6 million of crop losses in 2012, as estimated by crop specialists surveyed in each state. Our early warning network is paying off.”

“Growers are looking at a crisis where nature, markets, and risk all meet,” Koehler said. “They were hanging out there, and needed an integrated pest management system to confront this problem and help them out. This is exactly why we need the Northeastern IPM Center. It can address the issue on a regional scale, quickly providing resources to let us work together to solve this problem.”

Singing the Same Tune

Koehler and his group distributed fact sheets that Kathy Demchak, an extension associate at Penn State, produced with Northeastern IPM Center funds. Demchak networks with growers, making sure they are aware SWD is out there. “Unfortunately, sometimes growers haven’t noticed the pest, and haven’t realized how infestations could quickly get so bad,” Demchak said. “They were facing 50 percent crop loss, or had to shut down entirely at the peak of harvest.” And, she adds, crop damage is preventable if caught early. The key is getting people to monitor for SWD.

“What’s really impressed me is how interested extension educators are in helping growers,” Demchak said. “Even in these days of cutbacks and heavy workloads, these people are making an extra effort to improve a situation. When we pull in the same direction, we reach a common goal.”