Valley grape growers fear pest from Napa

FRESNO -- A new grape pest has been discovered in Napa County, and Valley grape growers are hoping it doesn't hitch a ride south.

State agricultural officials have confirmed that the European grapevine moth and larvae have been detected in the Oakville region of Napa County -- one of the state's premier wine grape growing regions.

The moth is considered a destructive pest because the larvae feed on grape bunches, ruining the berries and contributing to mold problems.

 It's the first known detection of the moth in the United States.

Monica Cooper, a University of California viticulture farm adviser in Napa County, said evidence of the moths' damage began showing up several months ago, but growers did not know what it was.

"We started an investigation as more growers started reporting more of it," Cooper said.

Once the bug was positively identified, the Napa County Department of Agriculture, the U.S. Department of Agriculture and the California Department of Food and Agriculture began setting insect traps to determine where else the bug may be.

"This is a pest that needs to be taken seriously, and that is exactly what we are doing," said Greg Clark, assistant agricultural commissioner in Napa County.

San Joaquin Valley grape-industry officials say they are keeping a close watch on what happens up north. The Valley is the leading producer of raisins and a major contributor of juice concentrate.

Kent Daane, an insect pest specialist with UC cooperative extension, said that while no one knows exactly how the pest arrived, he suspects international airline travel.

Daane said that while this latest pest is not as feared as those carrying plant-killing diseases, it can increase the cost to growers who have to battle it.