By John Toole
---- — LONDONDERRY — Sunnycrest Farm is on the front line in a nationwide agricultural war against an unwanted pest.
University of New Hampshire Cooperative Extension has placed traps on the farm as it monitors a dangerous, spreading threat to valuable crops.
The enemy to farmer Dan Hicks’s livelihood, and the enjoyment of Granite State fruit lovers, is the Asian spotted-wing drosophila.
It harms blueberries and raspberries — both grown at Sunnycrest — and other fruit, including grapes and peaches.
Since 2008, the fly has moved east across the continental U.S. from California, damaging crops along the way.
“This is one nasty fly,” Hicks said. “UNH has been coming down checking our plants for it. So far, so good. We haven’t had to get worried about it yet.”
The fly hasn’t approached nearby Mack’s Apples, farm manager Mike Cross said.
“We haven’t seen it,” Cross said. “We’re being vigilant about it.”
The fly isn’t a concern to Mack’s main crop, apples, but is a worry for peaches.
Cross said the fly likes soft fruits that are easy for it to attack.
“We have 3 acres of peaches we will probably spray,” Cross said.
Peaches generate $50,000 to $60,000 yearly in sales for Mack’s, he said.
Zorvino Vineyards in Sandown also is relieved the fly hasn’t attacked 3 acres of grapes grown for the winery.
“We have not seen any yet,” Zorvino’s Amy Zanello said. “We haven’t been affected.”
UNH Cooperative Extension field specialist George Hamilton said the fly is in both Rockingham and Hillsborough counties, as well as states throughout the nation, including Massachusetts.
“This is a problem countrywide,” Hamilton said.
The fly’s presence in New Hampshire dates at least to 2011. UNH, based on a survey of growers last year, estimated New Hampshire crop losses at $1.5 million.
Across the border in Methuen, Mann Orchards abandoned this year’s late-season raspberry crop rather than take on the risk.
“We never really had trouble with the bug, but you listen and you hear about the problems,” Fitzgerald said, “so my thought was basically to eliminate the crop, rather than end up with some kind of problem that is difficult to manage.”
Raspberries amounted to less than 1 percent of Mann’s crops and Fitzgerald said he can re-start raspberries later once the experts have determined how best to manage the pest.
“We will let the researchers figure out what’s going on,” he said. “This is just kind of another twist in the road for farmers. This is not the first pest to come down the pike.”
Massachusetts Farm Bureau president Richard Bonanno said other growers have abandoned crops or are considering it.
“It’s a problem that’s difficult to control,” he said, “and this has prompted some growers to stop growing soft fruit like raspberries.”
He acknowledges their better-safe-than-sorry approach.
“The hope is down the line there will be better controls for it,” he said.
The female is able to easily lay eggs in ripening fruit with a serrated ovipositor.
“It’s like a serrated knife,” Bonanno said. “They are able to saw into good fruit.”
Reproduction is prolific, as many as 100 eggs a day. The fly also undermines fruit so other pests can cause harm.
“We can see eight to 12 generations per year,” Hamilton said. “It’s a harder insect to get ahead of.”
State agricultural officials are collecting and sharing data with their peers as they confront this challenge.
Hamilton said cherry and prime season strawberry crops have escaped damage in New Hampshire thus far, though late season strawberries are vulnerable.
“It seems like the first catch is from the first to the middle of July,” Hamilton said.
Officials don’t really know why, though heat and length of day may have something to do with it.
“Last year, the middle of August was when they exploded, damaging raspberries and blueberries,” Hamilton said.
There is debate whether tomatoes could suffer, too, though that hasn’t happened yet and Hamilton is skeptical.
The fly is small, so its eggs are barely visible.
But their presence can make fruit degrade and perish more quickly.
“This is not like a bruise on an apple,” Bonanno said.
Consumers need to act.
“Refrigerate and eat the fruit as soon as you can,” Hamilton recommends. “Take out what you need.”
There’s no reason to abandon local growers, officials say, because the fly is virtually everywhere across the fruited plain.