An urgent consumer alert has been issued after an invasive pest was found on grapevines distributed to Costco stores throughout California.
The El Dorado County Agricultural Commissioner is advising residents to take precautions after the glassy-winged sharpshooter was found on grapevines delivered to Costco stores between April 21 and May 26, 2026.
People who purchased grapevines or other plants during that period are being urged to contact the El Dorado County Agriculture Department at (530) 621-5520 or email eldcag@edcgov.us immediately to arrange pickup of grapevines or inspection of other plants and receive guidance on preventing further spread and infestation.
For grapevines, residents are instructed to place two garbage bags over the plants and secure them tightly. For other plants, they should schedule an inspection with the department. People are also being told not to attempt to return, transport, or relocate plants and not to place them in trash or compost bins.
According to the U.S. Department of Agriculture Animal and Plant Health Inspection Service, the glassy-winged sharpshooter is a large leafhopper about one-half inch long with a flat, triangular-shaped head and large eyes. It spreads Pierce’s disease when feeding on grapevines.
The USDA Animal and Plant Health Inspection Service describes Pierce’s disease symptoms as including new branches that do not mature properly, with patches of green, or “green islands,” surrounding mature brown bark.
Symptoms may spread along branches from the point of infection toward the tip and more slowly toward the base, with tips of branches and roots potentially deteriorating.
Leaves may turn yellow or red along the edges and eventually dry and die in circular patterns. Grapes may wilt and dry or “raisin up” before harvest. Leaves may fall early while leafstalks remain, creating a “matchstick” appearance.
Not all infected grapevines show every symptom, according to the USDA Animal and Plant Health Inspection Service.
The USDA Animal and Plant Health Inspection Service also states there is no treatment for Pierce’s disease. Once a grapevine shows symptoms, it must be removed and destroyed to stop the spread. Recovery is unlikely if symptoms appear during the same growing season, especially in highly susceptible varieties.
“El Dorado County has been fighting a costly eradication effort in El Dorado Hills since October 2024 against the Glassy-winged sharpshooter, which poses an immediate and serious threat to EL Dorado County vineyards. This pest transmits the bacterium Xylella fastidiosa, which causes the deadly Pierce’s disease in grapevines,” said LeeAnne Mila, El Dorado County Agricultural Commissioner. “To combat this new potential pathway of spreading this invasive pest, we are asking for community-wide cooperation to help limit this risk,” she added. “If you recently purchased grapevines or other plants at any Costco, contact the Agriculture Department so we can safely dispose of vines and inspect other plants.”
Officials said members who purchased grapevines from a Northern California Costco should receive emails regarding refunds for their purchase. They added that the pest is highly mobile and immediate action is needed, and that containment is vital to protecting agricultural resources in El Dorado County and across California.
