WSDA hunts for wine grape pests

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YAKIMA, Wash. — The state Department of Agriculture is setting up to 1,000 traps in June to protect Washington wine grapes from four species of destructive moths.

It’s also looking for two other pests. One previously found in the state attacks vine roots and is considered the most serious grape pest in the world.

None of the four moths has been found in the state in trapping in the past two years but the department wants to help growers prevent them from getting established, said Mike Klaus, WSDA entomologist in Yakima.

One of the four, the European Grapevine Moth, was found in California’s Napa Valley in 2009 and became a serious threat.

In 2013, USDA’s Animal and Plant Health Inspection Service released $16.9 million in emergency funding to combat the moth in California. Mating disruption and other control techniques have had some success, Klaus said.

The USDA is helping fund WSDA’s effort. If the European Grapevine Moth, European Grape Berry Moth, Grape Tortrix or Grapevine Tortrix are found in Washington, more trapping would occur to find the center of infestation and the industry and government would determine action.

“If any of these pests were to become established here, they could pose a serious threat to our grape and wine industries,” said Klaus, adding chances they are here are slim.

That possibility is a huge concern to the industry, which greatly appreciates the trapping, said Vicky Sharlau, executive director of the Washington Association of Wine Grape Growers in Cashmere.

The highest risk is the European Grapevine Moth since it’s in California, Klaus said. It could arrive on landscaping plants being sold at nurseries and big box stores.

“That’s a likely pathway. We like to focus our trapping near those,” he said.
By Dan Wheat

Moths could find any number of host plants and then spread to vineyards, he said.

Different traps are hung for each species. The traps emit the pheromone or female scent of that species. Scents work up to a half-mile away.

Traps were being placed in vineyards and backyard vines in most of the state’s 13 wine grape growing regions in the last few days of June. Trapping will be heaviest in Yakima, Benton, Franklin and Walla Walla counties, he said.

Traps will be checked every two to four weeks during the summer and taken down in September. Final results will be compiled in winter.

About 100 to 200 of the sites also will trap for the vine mealybug, which has not been found in the state.

WSDA will conduct its first root samples since 2002, looking for grape phylloxera, an aphid-like pest that attacks grape roots. It is considered the most serious grape pest worldwide, almost wiping out French vineyards in the 1880s. It was detected in Washington vineyards and backyard vines in 1988, 1989 and 2002.

It wasn’t severe and Washington State University scientists believe it doesn’t do well in Washington soils and desert climate, Klaus said.

“We suspect it’s out there at low levels,” he said, “but different grape varieties coming in could be more susceptible, so it’s good to check.”