Bay Area agriculture officials are on high alert after a Fresno County nursery imported a dangerous grapevine pest into the region via Costco sales to consumers.

On Tuesday, Napa, Sonoma, Marin, Solano, San Mateo, Santa Cruz and Yolo counties all reported that the infamous glassy-winged sharpshooter had been found in grapevines sold at Costco locations throughout the Bay Area. On Wednesday, Contra Costa County joined their ranks.

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,” said county Agricultural Commissioner Matt Slattengren. “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.

“We are working closely with our state partners and other affected counties to get ahead of this, but we need the public’s help.”
Matt Slattengren, Contra Costa County Agricultural Commissioner

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.

The glassy-winged sharpshooter feeds on the xylem fluid of a large number of plants, and is a particular menace to Northern California’s grape vineyards. (Photo courtesy of University of California via Bay City News)

“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.

Kiley Russell writes primarily for Local News Matters on issues related to equity and the environment. A Bay Area native, he has lived most of his life in Oakland. He studied journalism at San Francisco State University, worked for the Associated Press and the former Contra Costa Times, among other outlets. He has covered everything from state legislatures, local governments, federal and state courts, crime, growth and development, political campaigns of various stripes, wildfires and the aftermath of Hurricane Katrina.