Invasive grapevine-killing pest found in hundreds of Bay Area plants

The plants, numbering in the hundreds, came from Burchell Nursery in Fresno County.

"The glassy-winged sharpshooter poses an immediate and serious threat to grapevines and agricultural landscapes throughout Contra Costa County," county Agricultural Commissioner Matt Slattengren said. "We are working closely with our state partners and other affected counties to get ahead of this, but we need the public's help."

Contra Costa County officials said that roughly 200 plants were sold in the county before the infestation was detected. The plants came from five Costco stores in Danville, Concord, Brentwood, Richmond and Antioch.

The remaining plants were destroyed after most were confirmed to have multiple life stages of the insect present.

Glassy-winged sharpshooters spread Pierce's disease, a bacterial infection that is fatal to grapevines and can also damage almond, citrus and ornamental plants, posing a significant threat to California agriculture and home gardens.

An adult glassy-winged sharpshooter can drain 200 to 300 times its body weight in water every day and an infested tree can lose up to 15 gallons per day, according to agricultural officials in Marin County, who said inspectors have surveyed plants from earlier Novato Costco shipments as well as other nearby and commingled plants and increased trapping efforts.

"Costco is not at fault here, and they've been an exceptional partner throughout this process," Marin County Agricultural Commissioner Joe Deviney said. "They acted quickly, cooperated fully and helped us reach customers as fast as possible."

On Tuesday, officials also reported that 220 grapevines shipped from Burchell Nursery were sold in Napa County and that only 63 have been destroyed — the other 157 grapevines remain unaccounted for.

Anyone who believes they might have purchased a plant since April 21 that might be infected should not try to return them to the store.

Instead, people should place two garbage bags over the plant, secure them tightly, then immediately contact the local agriculture commissioner using information found at the California Department of Agriculture website at www.cdfa.ca.gov/exec/county/documents/countycommissionersealercontactinfo.pdf.