Coordinated Efforts Underway Following GWSS Detection on Grapevines
Published Friday, June 5, 2026
Glassy-winged sharpshooter infestations were recently linked to grapevines sold at Northern California Costco locations in April and May. In response, shipments were halted, infested plants were destroyed, and ongoing trapping and inspection efforts are underway. The situation remains under investigation by the California Department of Food and Agriculture and county agricultural commissioners. While Costco has notified customers and cooperated with CDFA guidance, many plants remain unaccounted for. Efforts are also underway to help CDFA identify and contact affected purchasers to support mitigation and eradication activities.
If you purchased a grapevine, citrus tree or other fruit tree at Napa Costco or neighboring Costco locations in April or May, you should:
- Keep the plant isolated in its original pot or container.
- Do not plant the grapevine or tree if you have not already done so.
- If possible, place the plant(s) in two secured trash bags, one inside the other, and seal them closed.
- Do not attempt to return, transport or relocate the plant.
- Do not place the plant in the trash or a compost bin.
- Immediately contact the Napa County agricultural commissioner’s office at 707-253-4357 or agcommissioner@countyofnapa.org.
- An agricultural inspector will be dispatched the same day to examine the grapevine, fruit tree(s) and any nearby host plants.
- As a precautionary measure, glassy-winged sharpshooter monitoring traps may be placed on the property.
Contact Rebecca Harper, rharper@cfbf.com, or your Farm Bureau regional manager for assistance.
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