Apple Maggots Threaten Skagit County Crop Commercial Apple Producing Region Facing Quarantine

Skagit County’s apple growers are facing the threat of a quarantine because of an infestation by apple maggots.

Such infestations in the past have led to quarantines on King, Snohomish, Spokane and Clark counties. But few apples come out of those counties.

A quarantine in Skagit County would be the first for a significant commercial apple producing region.

“It could be major,” said Don Williamson, a Mount Vernon grower.

A maggot infestation could be devastating for the county. The fledgling industry remains relatively small at 350 acres planted with most trees not yet at full production. The crop generated $762,000 to farmers in 1996.

The apple maggot fly - officially Rhagoletis pomonella - pokes a tiny hole in the apple and lays its eggs inside the fruit’s flesh. The maggot burrows into the apple and exudes a bacterium that turns the apple to mush.

The problem was discussed at the Western Washington Commercial Tree Fruit Workshop in Mount Vernon last week. About 40 state regulators and the top regional growers attended the workshop at the Washington Sate University Research and Extension Unit.

Initial surveys turned up a single fly in Burlington in 1992. No flies were found again until 1996, when eight were captured in 5-by-8-inch trap boxes. Last year, 32 flies were found at 16 different sites, said Mike Klaus, an entomologist with the state Department of Agriculture.

Quarantine is likely, said Dyvon Havens, a Washington State University cooperative extension agent.

What this means to farmers is increased pesticide spraying, intensive inspections and negative economic effects that come with a quarantine.

Unfortunately, as with past trappings, most of the bugs come not from commercial orchards but from untended older trees in back yards.

“We’re looking to form a pest board which would give legal authority to tell residential people to spray or have the right to cut down their tree,” Williamson said.

One worm, or maggot, in a grower’s apples means that the entire harvested crop needs to be put in cold storage, or what the industry calls “controlled atmosphere,” for between 40 and 90 days to kill the bug.

“The problem is we don’t have the capacity,” Williamson said.

East of the Cascades, where most of the state’s apple industry is located, packers do have the capacity, but those in the business may not be interested in accepting potentially buggy apples.

There is also a fear that infestation could affect international sales.

Currently, Mexico, Chile and British Columbia won’t accept apples from infested areas, Klaus said.

A hearing will be set for mid-May on a proposed Skagit County quarantine. A final decision is expected from the state in June.