A tiny insect hitchhiking on grapevines sold at Costco stores across Northern California could threaten one of America’s most valuable wine regions — and hundreds of those plants are still sitting in backyards right now.
Story Snapshot
- Glassy-winged sharpshooters were found on grapevines sold at Northern California Costco locations between late April and late May 2026, shipped from Burchell Nursery in Fresno.
- Costco promptly alerted agricultural officials, destroyed infested plants, and is issuing full refunds to affected members.
- At least 10 counties issued public alerts, but hundreds of purchased grapevines remain unaccounted for in people’s yards.
- The insect spreads Pierce’s disease, a bacterial infection that kills grapevines and could devastate Napa and other wine-producing regions if not contained.
What the Glassy-Winged Sharpshooter Actually Does to Vineyards
The glassy-winged sharpshooter is not just a nuisance bug. It carries Pierce’s disease, a bacterial infection that clogs a grapevine’s water system from the inside. There is no cure. Once a vine is infected, it dies.
Wine grower Nello Olivo put it bluntly: if the pest reaches Napa, it could kill all the vines there. Lodi Wine Grape Commission Executive Director Stuart Spencer added that Pierce’s disease makes grape farming “economically unviable.” That is not an exaggeration — it is a statement of agricultural fact.
California’s wine industry generates billions of dollars each year. A sharpshooter outbreak that reaches established vineyards would not just hurt farmers. It would ripple through the entire regional economy.
That is why agricultural commissioners across at least 10 counties moved fast, and why the stakes here are far bigger than a Costco plant return.
How Infested Grapevines Reached Store Shelves
Burchell Nursery in Fresno shipped grapevines to Costco locations across Northern California. Inspectors later found multiple life stages of the glassy-winged sharpshooter on those plants, meaning the infestation was established before the vines ever left the nursery.
Marin County Agricultural Commissioner Joe Devinney said it plainly: “What broke down was there was an infestation in the nursery and it wasn’t caught. And then they were shipped and we weren’t notified.” The failure happened upstream, not at the store level.
The California Department of Food and Agriculture has since placed Burchell Nursery under stricter treatment, inspection, and shipping rules. That is the right call.
Supply chain accountability matters, and a nursery shipping infested stock to a major retailer without catching it first is a serious breakdown in the system that protects California agriculture from exactly this kind of threat.
Costco’s Response Has Been Cooperative and Fast
Agricultural officials across multiple counties are not blaming Costco. The company notified authorities quickly after the infestation was discovered.
Inspectors destroyed 160 infested grapevines delivered to Costco locations in Sacramento. In Napa County, 63 of 220 delivered grapevines were destroyed after one sharpshooter egg mass was found.
Costco is directly contacting members who bought plants during the affected window and issuing refunds. The Sacramento County Agricultural Commissioner’s Office called Costco “a cooperative partner.” That kind of prompt, transparent response is how businesses should handle a public safety issue.
Hundreds of Plants Are Still Unaccounted For — Here Is What to Do
The problem that remains is scale. Hundreds of grapevines sold at Sacramento Costco locations alone are still in customers’ hands who may not know about the alert. Napa County reports 157 grapevines from its local store are still unaccounted for.
If those plants are sitting in a yard near a vineyard, the risk is real and active. The window for affected purchases runs roughly from April 21 to May 21, 2026, though some county alerts list slightly different dates.
If you bought a grapevine at a Northern California Costco during that period, do not move the plant. Place it in two sealed garbage bags without shaking it.
Then contact your local county agricultural commissioner’s office for disposal instructions and contact Costco for a refund. Do not compost it, do not transport it, and do not plant it. The insect can fly to nearby plants if disturbed, which is exactly how a contained problem becomes a regional disaster.
Costco issues warning notice for plant due to invasive insect infestation concern https://t.co/W4FDJ2iqrC
— FOX Business (@FoxBusiness) July 12, 2026
The Bigger Pattern Nobody Is Talking About
This incident is not a fluke. Invasive pests repeatedly enter California through nursery stock sold at major retailers. Research shows that 61% of plant species identified as invasive in the United States remain legally available through the plant trade.
California’s pest prevention system is under growing strain from trade volume, e-commerce, and aging infrastructure. Large retailers move plants in bulk across wide geographies.
That makes them unintentional amplifiers when a nursery ships infested stock. Better pre-shipment inspection at the source is the fix — not a reason to avoid buying plants, but a clear argument for stronger nursery oversight before anything gets loaded onto a truck.
Sources:
foxbusiness.com, kcra.com, reddit.com, pacificsun.com, ag.santaclaracounty.gov, facebook.com
