Purchased a Grapevine at Costco? Important GWSS Information
Last updated: June 15, 2026
The California Department of Food and Agriculture (CDFA) is responding after invasive glassy-winged sharpshooter (GWSS) insects were found on shipments of grapevines sold at select Costco locations in Northern California between April 21 and May 21.
If you purchased a grapevine from Costco in an affected county during that timeframe, contact your local County Agricultural Commissioner’s Office right away.
GWSS is an invasive insect pest that spreads the bacterium that causes Pierce’s disease, a fatal grapevine disease that threatens California vineyards. The pest can also damage citrus trees, landscape plants and other crops. Early detection and rapid response are critical to preventing the pest from spreading further.
News release: CDFA Urges Immediate Reporting of Grapevines Purchased at Costco (Español)
What To Do If You Purchased a Plant
If you purchased a grapevine from Costco in an affected county between April 21 and May 21, take the following steps:
Isolate the Plant
- Keep the plant in its original pot or container and away from other plants.
- Do not put the plant in the ground if you have not already done so.
- If possible, place the plant inside two trash bags, one inside the other, and seal them closed.
- Do not return, transport or relocate the plant.
- Do not place the plant in the trash or compost bin.
Contact Your Local County Agricultural Commissioner’s Office Right Away
Find your County Agricultural Commissioner
- An agricultural inspector will come to examine the plant and nearby host plants.
- If inspectors find GWSS on the grapevine, they will safely remove and dispose of the plant.
- GWSS monitoring traps may also be placed on or near the property.
Impacted Costco Locations By County
Contact your local agriculture department (websites and phone numbers listed below)
As of 6/5/2026 at 5:40 p.m.
- Alameda County or call 510-670-5232
- Butte County or call 530-552-4100
- Contra Costa County or call 925-608-6600
- Fresno County or call 559-600-7510
- Humboldt County or call 707-441-5260
- Kings County or call 559-852-2830
- Marin County or call 415-473-6700
- Mendocino County or call 707-234-6830
- Merced County or call 209-385-7431
- Monterey County or call 831-759-7325
- Napa County or call 707-253-4357
- Placer County or call 530-889-7372
- Sacramento County or call 916-875-6603
- San Joaquin County or call 209‑953‑6000
- San Mateo County or call 650-363-4700
- Santa Clara County or call 408-918-4600
- Santa Cruz County or call 831-763-8080
- Shasta County or call 530-224-4949
- Solano County or call 707-784-1310
- Sonoma County or call 707-565-2371
- Stanislaus County or call 209-525-4730
- Tulare County or call 559-684-3350
- Yolo County or call 530-666-8140
- Yuba County or call 530-749-5400
Response and Containment Efforts
The Pierce’s Disease Control Program, county agricultural commissioners continue to respond to this situation. Finding and removing infested plants quickly is the best way to prevent GWSS from spreading and protect California agriculture.
Response activities include:
- Strengthening oversight at the source nursery. The nursery is operating under stricter treatment, inspection and shipping protocols to help prevent the spread of GWSS.
- Locating potentially affected grapevines through public outreach, reports from consumers and direct customer outreach across the affected counties and neighboring at-risk counties.
- Inspecting reported plants and safely disposing of potentially infested plants to help prevent the spread of GWSS.
- Placing traps near stores and locations where purchased vines were taken to monitor for GWSS.
Outreach Material
For editable design files, please contact PDCP: email or call (916) 900-5024
- Glassy-winged sharpshooter flyer - English - Español
- Glassy-winged sharpshooter brochure - English - Español
