The western grapeleaf skeletonizer (WGS) pest is back in Napa County, Calif. after an eight-year hiatus.

"This is a destructive and serious pest," said Napa County Agricultural Commissioner Greg Clark on July 6.

An adult WGS was discovered in a pheromone-baited trap in Calistoga on Tubbs Lane.

Excessive feeding can damage fruit and lead to secondary fungal damage and grape cluster rot.

Read the July 6 Western Farm Press WGS article online on the pest and potential danger to grape leaves and grape clusters at http://westernfarmpress.com/grapes/western-grapeleaf-skeletonizer-pest-found-napa-county-vineyard-trap.

Clark said, “We do not want this pest to become established in Napa County.”

Pest detection trappers from the Ag Commissioner’s Office were deploying 25 additional traps within a mile radius of the Calistoga find.  

Here are several photos of WGS larvae and adults. Photos by Jack Kelly Clark, courtesy of the University of California Integrated Pest Management Program.