One of two species in the vinegar fly family that’s proven harmful to crops has traveled up the West Coast and into Skagit Valley, becoming a threat to small fruit crops along the way.

The Drosophila suzukii began leaving its mark on crops in the state at the end of summer, showing early on that it’s willing to infest a wide range of thin-skinned fruit.

While the fly’s late appearance in the state might have gone unnoticed by small fruit growers who had already shipped out their summer products, researchers can’t ignore the pest’s damaging potential to future crops.

Small fruit crops, such as blueberries, raspberries and strawberries, make up $12 million worth of crops in the valley, said Don McMoran, an instructor at the Washington State University Skagit County Extension.

Unlike the common vinegar fly, which lays its eggs in rotting fruit and helps decompose food, the spotted-wing Drosophila, as it’s called, prefers to use still-growing fruit as its incubator.

“This particular insect is feeding directly on the product that farmers grow to sell,” said Lynell Tanigoshi, a small fruit entomologist at WSU NWREC.

Tanigoshi and his research associate, Beverly Gerdeman, will be spending the winter breeding colonies of the insect so they can study the best methods for killing them.

“If you’re a grower of strawberries, and we’re talking about a pest that attacks fruit directly, you’re gonna ask ‘How do we kill them?’” Tanigoshi said.

That’s what farmers began asking when the fly first started appearing during the tail-end of small fruit season in the state.

The fly, originally from Japan, has made its way into South America and up the west coast of North America over the past year. It’s since been spotted in California, Oregon, Washington, British Columbia and Florida, Tanigoshi said.

Emergency

The spotted-wing Drisophila’s sudden prevalence has spurred researchers at universities along the West Coast to form a taskforce that will study and recommend methods for preventing the pest.

Tanigoshi said the willingness of competitive researchers to share their findings shows the urgency of the situation for North American farmers.

WSU’s researchers received $10,000 of emergency funding from the Red Raspberry Commission to begin their study, which they hope will produce results for local farmers by March or April.

“We are the ones priming the research pump, but we are hoping and trusting that there will be a number of other contributors,” said Henry Bierlink, the commission’s executive director.

Whatcom County produced about 58 million pounds of raspberries last year, Bierlink said, making it the largest growth center of raspberries in the state.

Researchers believe raspberries will be especially vulnerable to the new insect because of the long season during which they ripen.

While researchers at other institutions working with the taskforce will study the fundamentals of the fly, such as its life cycle and biological makeup, Tanigoshi and Gerdeman will focus on finding the right chemical to keep the pest away.

Richard Sakuma of Sakuma Bros. Farms said that’s the information he’s eager to get his hands on.

Sakuma’s farm grows more than 1,000 acres of strawberries, raspberries, blueberries and blackberries, all of them susceptible to the fruit-piercing fly.

Though he’s been monitoring the pest since it started making mush of his late season fruit in August, Sakuma said he’s looking forward to the findings of local experts who are studying the fly.

“I’m concerned, but I’m not in this hopelessness state of panicking and worrying,” Sakuma said. “I guess I’m hopeful that, with the research effort, we’ll be able to manage these things.”

Tanigoshi said it’s likely they’ll recommend farmers use a rotation of pesticides to keep the flies at bay.

Of the 12 federally registered insecticides the team is testing, some already might be a part of farmers’ spray programs against other insects.

The team also will work toward solutions for organic farmers who can’t use pesticides, but they acknowledge there’s little that could prevent the fly’s infestation of wild fruit plants, such as the blackberry brambles found throughout the state.

One of a kind

Initial reports in the state of fly-damaged crops filtered in from both farmers and backyard growers of a range of small fruits, Gerdeman said.

So far, researchers are well-versed at identifying the unique pest.

While the male fly is distinguished by a spot on each wing, the female’s distinctive body part poses the real danger to thin-skinned fruit.

She uses a “sawlike ovipostor” on her back end to cut through the skin of ripening fruit and lay her eggs inside.

“She thinks she’s a fruit fly,” Tanigoshi said. “She can put her eggs inside a nice (piece of) fruit, whereas, all the other species of this family don’t do that.”

The female’s eggs grow into maggots and then pupae inside the fruit, all the while eating away at a farmer’s otherwise salable product.

Though researchers still have a lot to learn about the newest pest in the area, they could have years to continue studying the unique species.

If they make it through the winter, Tanigoshi said, they’ll be here forever.

Whitney Pipkin can be reached at 360-416-2112 or at .