Santa Clara County Launches Targeted Campaign to Retrieve Costco‑Sold Grapevines Threatened by Invasive Glassy‑Winged Sharpshooter

Officials in Santa Clara County, California, have initiated a door‑to‑door effort to retrieve grapevines sold at select Costco locations that may be harboring an invasive pest.

The glassy‑winged sharpshooter, a pest native to the southeastern United States and northeastern Mexico, was detected on vines sold at several Costco stores within Santa Clara County — including Palo Alto, San Jose, and Santa Clara — between April 21 and May 19, according to the county’s Division of Agriculture. Similar plant material had also been distributed to other regions of California.

Glassy‑winged sharpshooters are indigenous to the American Southeast and northeastern Mexico, but they are classified as an invasive species in California. These insects vector Pierce’s disease, a condition that is lethal to grapevines and can devastate vineyards, nurseries, and farms. Beyond grapes, the pest can also impair citrus trees, ornamental plants, and a range of other crops, threatening a $73 billion wine industry.

The first major outbreak occurred in August 1999 in Riverside County, where more than 300 acres of grapevines infested with the glassy‑winged sharpshooter became infected with Pierce’s disease and were subsequently eradicated.

Costco reported that over 1,300 grapevine plants potentially affected by the pest were sold to customers in Santa Clara County, the local agricultural agency noted.

County officials began door‑to‑door outreach on Monday, delivering informational packets and collection kits — such as zip ties and plastic bags — to residents who had purchased the possibly infested plants. State officials, in collaboration with Costco, supplied the county with customer purchase data to aid the effort, said Ericka Mora, Deputy Agricultural Commissioner of Santa Clara County.

Residents are advised not to move, compost, or otherwise dispose of the plants themselves, as doing so could facilitate further spread of the insect or disease, Ms. Mora warned.

Scheduled collection activities commenced on Wednesday, although some vines were already gathered during Monday and Tuesday’s field visits. Early targeting has centered on the southern portion of the county — including Gilroy, Morgan Hill, and San Martin — areas that host numerous wineries.

Mora reported that residents have been cooperative to date, though she does not yet possess a precise tally of remaining vines yet to be retrieved from purchasers.

Santa Clara County is among at least 24 jurisdictions statewide identified as vulnerable to the infestation, per a California Department of Food and Agriculture release.

The department further cautioned that desert willow trees sold at Costco locations in 15 counties between June 24 and July 3 could be similarly impacted.

Burchell Nursery’s Fresno facility, which shipped the suspect grapevines in May, is now subject to enhanced treatment, inspection, and shipping protocols, the department noted. The nursery did not immediately respond to a request for comment.

The California Department of Food and Agriculture outlined a multi‑pronged response that includes tracking potentially affected grapevines and desert willows throughout the impacted and adjacent counties, inspecting and safely disposing of contaminated plants, and deploying traps to monitor for the pest near stores and other sites where purchased plants were taken.

Neither the California Department of Food and Agriculture nor Costco responded promptly to requests for comment.

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