05/28/2026
CDFA RESPONDING TO INVASIVE PEST FOUND ON PLANTS SOLD AT NORTHERN CALIFORNIA COSTCO LOCATIONS
Purchased a Grapevine or Fruit Tree at Costco? Contact Your County Agricultural Commissioner The California Department of Food and Agriculture’s Pierce’s Disease Control Program (PDCP) is working with Costco Wholesale and county agricultural officials after invasive glassy-winged sharpshooter (GWSS) insects were found on grapevine shipments sold at select Costco locations in Northern California between April 21 and May 19. GWSS is an invasive insect pest that can damage citrus trees, landscape plants and agricultural crops. The pest also spreads the bacterium that causes Pierce’s disease, a fatal grapevine disease that threatens California vineyards. Early detection and rapid response are critical to preventing the pest from spreading further. State and local agricultural officials identified the issue quickly and immediately began response and containment efforts. Fresno County Agricultural Commissioner staff and CDFA personnel have been working onsite at Burchell Nursery since May 19 to stop shipments, investigate the situation and determine corrective actions. Costco has been cooperative in notifying customers, issuing refunds and helping connect purchasers with local county agricultural commissioner offices for inspection and disposal guidance. GWSS has been confirmed on plants shipped to Alameda, Marin, Placer, Sacramento, San Mateo, Solano, Stanislaus and Yolo counties. Officials are still evaluating additional suspect samples from several other counties, including Butte, Contra Costa, Humboldt, Merced, Napa and Sonoma counties. What To Do If You Purchased a Plant If you purchased a grapevine, citrus tree or other fruit tree from Costco in an affected county between April 21 and May 19, take the following steps: • Isolate the plant: o Keep the plant in its original pot or container and away from other plants. o Do not put the plant in the ground if you have not already done so. o If possible, place the plant(s) in two trash bags, one inside the other, and seal them closed. o Do not return, transport or relocate the plant. o Do not place the plant in the trash or compost bin. • Contact your local County Agricultural Commissioner’s Office right away: o An agricultural inspector will come to look at the plant and other nearby host plants. o GWSS monitoring traps may be placed on the property For more information, visit the California Department of Food and Agriculture.
