A tiny insect no bigger than your thumbnail just put California’s entire wine industry on edge — and hundreds of Costco shoppers may have unknowingly brought it home.
Story Snapshot
- Grapevines sold at Northern California Costco locations between late April and mid-May 2026 were found to carry the glassy-winged sharpshooter, a destructive invasive insect that spreads Pierce’s disease and can wipe out entire vineyards.
- The infested plants came from Burchell Nursery in Fresno, which failed to detect or report the infestation before shipping to Costco stores across at least 10 counties.
- Costco alerted agricultural officials promptly, destroyed hundreds of infested plants, and began issuing refunds — but hundreds more grapevines remain unaccounted for in customers’ homes.
- If you bought a grapevine at a Northern California Costco between April 21 and May 21, 2026, do not return it to the store — contact your county agricultural commissioner immediately.
What the Glassy-Winged Sharpshooter Actually Does to Vineyards
The glassy-winged sharpshooter is not just a nuisance bug. It carries a bacterium called Xylella fastidiosa, which causes Pierce’s disease in grapevines. The disease blocks water flow inside the vine. The plant slowly starves and dies, and there is no cure.
Wine grower Nello Olivo put it plainly: if the insect spreads into Napa, it could kill every vine in the valley. Lodi Wine Grape Commission Executive Director Stuart Spencer said Pierce’s disease makes grape farming “economically unviable.” That is not panic — that is agricultural reality.
Costco issues warning notice for plant due to invasive insect infestation concern https://t.co/W4FDJ2iqrC
— FOX Business (@FoxBusiness) July 12, 2026
How Infested Plants Reached Costco Shelves
Burchell Nursery in Fresno grew and shipped the grapevines. Inspectors found multiple life stages of the glassy-winged sharpshooter on the plants — meaning eggs, nymphs, and adults were all present. The nursery did not catch the infestation before shipping, and it did not notify local agricultural agencies.
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 California Department of Food and Agriculture has since placed Burchell Nursery under stricter inspection and shipping rules.
Costco is not the villain here, and every county agricultural office involved has made that clear. The retailer did not grow the plants, did not know about the infestation before the sale, and acted quickly once it was discovered. Multiple county commissioners called Costco a “cooperative partner.”
The company alerted officials, destroyed infested inventory, issued refunds, and began directly contacting members who bought plants during the affected window. That is a textbook response, and it deserves recognition as such.
The Scope of the Problem Across Northern California
Sacramento County agricultural inspectors destroyed 160 infested grapevines delivered to Sacramento-area Costco stores. In Napa County, inspectors found one glassy-winged sharpshooter egg mass and destroyed 63 of 220 delivered vines — but the remaining 157 are still unaccounted for.
At least 10 counties issued public alerts, including Sacramento, Napa, Marin, Sonoma, Solano, Yolo, Contra Costa, Sutter, Yuba, and Santa Clara. The scale of the distribution is what makes this serious. One nursery, one retailer, and one shipping window created a pest-exposure event spanning much of Northern California.
What You Need to Do If You Bought One of These Plants
Do not bring the plant back to Costco. Do not compost it or throw it in a green bin. Agricultural officials are asking buyers to double-bag the plant in sealed garbage bags and then call their local county agricultural commissioner’s office for disposal instructions.
Costco is issuing full refunds and can connect you with the right county office. The sale window most commonly cited runs from April 21 to May 21, 2026, though some counties have listed slightly different dates — when in doubt, report the plant anyway.
Costco issues warning notice for plant due to invasive insect infestation concernhttps://t.co/jHrISjWGP8
— Nepa Here (@nepahere) July 13, 2026
Why This Keeps Happening in the Plant Trade
This incident is not a fluke. It fits a well-documented pattern in which invasive pests enter California through nursery stock before regulators catch them. A 2024 study found that 61% of 1,285 plant species identified as invasive in the United States remain legally available through the plant trade.
California’s own pest prevention system is under growing strain from trade volume, e-commerce, and aging infrastructure. The system caught this outbreak — but only after the plants were already in people’s yards.
That gap between shipment and detection is the real problem, and it will continue to produce incidents like this one until nursery inspection standards are strengthened at the source.
Sources:
foxbusiness.com, kcra.com, reddit.com, pacificsun.com, ag.santaclaracounty.gov, my.ucanr.edu
