SALEM -- The USDA does not plan to take quarantine action on a vinegar fly that recently showed up in Northwest orchards.

Mitch Nelson, an official with USDA Animal and Plant Health Inspection Service, said Tuesday, Sept. 22, federal inspectors believe the Drosophila suzukii "is all over the place."

APHIS typically does not take regulatory action against a pest that is widespread.

The fly is known to be present in five states and British Columbia, Nelson said, and is prominent in parts of Asia. It also has been reported in parts of Europe.

"The horse has left the barn," Nelson said. "The good news is we know of no country at this time taking quarantine action against it."

Drosophila suzukii, which feeds on ripe and ripening fruit, is established in Hawaii, and inspectors in recent weeks have reported finding it in California, Washington, Oregon and Florida.

Nelson believes the vinegar fly also is present in other states, but hasn't been found only because inspectors haven't looked for it.

A state must prove it doesn't have a particular pest before it can take regulatory action against it, he said.

APHIS inspectors include the fly among a list of "non-concern" pests.

Inspectors are rethinking pest classifications because of the problems that have arisen from the Drosophila suzukii, Nelson said.

"That's a positive thing that's going to come out of this," he said.

Nelson made his comments to about 100 growers who packed a meeting room at the Oregon State Fairgrounds on Tuesday, Sept. 22.

Oregon Department of Agriculture entomologist Helmuth Rogg told growers the pest has been found in 23 California counties, and in Benton, Lane, Douglas, Marion and Multnomah counties in Oregon. Washington has not conducted a survey, Rogg said, but a state inspector reported finding the fly on fruit in a Seattle neighborhood.

Nelson speculated the pest first arrived in the U.S. on fruit shipped from Japan.

The pest has been present there since the 1930s, according to research documents.

"Japan probably doesn't have a problem with it because of cultural reasons and biological reasons," Nelson said. He speculated the pest has natural biocontrol agents in Japan.

-- Mitch Lies