Invasive insect discovered in grapevine plants shipped to Sonoma County Costco stores

The Sonoma County Department of Agriculture/Weights & Measures is advising residents to take precautions after the invasive glassy-winged sharpshooter was found on plant shipments delivered to Costco stores in Santa Rosa and Rohnert Park.

On May 19, the Costco Wholesale store in Santa Rosa notified the Department of Agriculture/Weights & Measures that they had received a shipment of grapevines originating from Burchell Nursery in Fresno. During routine inspection, county staff identified multiple suspect life stages of the glassy‑winged sharpshooter, a significant agricultural pest capable of transmitting Pierce’s disease and posing substantial risk to vineyards and other susceptible crops. Upon discovery, staff contacted the delivering nursery to determine additional delivery points. They were notified that the same truck had delivered plant material to the Costco Wholesale location in Rohnert Park, as well as Novato. This nursery had also shipped plant material to several other counties in the state including Napa and Mendocino.

Staff followed up with an inspection at the Rohnert Park Costco and confirmed the presence of suspected glassy-winged sharpshooter life stages on the received plant material. The California Department of Food and Agriculture was notified of the findings and notified other counties of deliveries to their Costco’s and the potential for finding glassy-winged sharpshooters in their shipments.

Residents who purchased plants at Costco stores in Sonoma County since April 21 should please:

• For grapevines: place two garbage bags over the plants and secure them tightly.
• For citrus: follow the contact information below to schedule Agriculture Department inspection.
• Do not place plants in the trash or compost bin.
• Contact the Sonoma County Department of Agriculture/Weights & Measures at (707) 565-2371 or email Sonomaag@sonomacounty.gov to schedule inspection of grapevines and other plant material purchased at Costco stores between April 21 and May 20 and receive guidance on how to prevent further spread and infestation of the glassy-winged sharpshooter.

The shipping nursery is required by state quarantine laws to notify County Department of Agriculture offices prior to shipping plant material, which did not occur. All affected counties are responding with enforcement actions and seizing and destroying the infested plants. Tracking down the locally purchased plants is the top priority of the Sonoma County Department of Agriculture.

“Costco is not at fault here, and they’ve been an exceptional partner throughout this process,” Sonoma County Agricultural Commissioner Andrew Smith said. “They acted quickly, cooperated fully, and are working to notify members/customers as fast as possible. We’re fortunate to have such a proactive retailer working with us to protect Sonoma County agriculture.”

Glassy-winged sharpshooters pose an immediate and serious threat to Sonoma County vineyards because they transmit the bacterium Xylella fastidiosa which causes the deadly Pierce’s disease in grapevines, please contact the Department of Agriculture/Weights & Measures to safely dispose of vines and inspect other plants.

In addition to jeopardizing California agriculture, glassy-winged sharpshooters can damage plants in home landscapes. The Agriculture Department has been working successfully with residents in Sonoma County to intercept any plants that may be harboring the pest.

• University of California Agriculture information on glassy-winged sharpshooters
• California Department of Food and Agriculture disease control
• California Department of Food and Agriculture’s portal to report pests

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Media Contact:
Matt Brown, communications specialist
publicaffairs@sonomacounty.gov 
707-565-3040 

Sonoma County Department of Agriculture/Weights & Measures
Sonomaag@sonomacounty.gov
707-565-2371