Agency official warns grape vines from California Costco may carry invasive glassy‑winged sharpshooter

An agency official warned on May 29, 2026, that grape vines sold at California Costco stores between April 21 and May 21 may carry the glassy‑winged sharpshooter, an invasive insect that can spread a disease fatal to plants. The speaker said Costco is cooperating with the response.

The official advised anyone who bought grape vines from a California Costco during that period to isolate the plant in its original pot, keep it away from other plants, and not plant it in the ground. "If possible, place the plant into trash bags, one inside the other, and seal them closed," the agency official said, adding: "Do not return, transport, or relocate the plant." The advisory cautioned against placing affected plants in household trash or compost bins.

Buyers were told to contact their local county agriculture department so an agricultural inspector can visit, inspect nearby host plants and, if inspectors find glassy‑winged sharpshooter on the vine, safely remove the pest and dispose of the plant. The official said glassy‑winged sharpshooter monitoring traps may be placed on the property during inspections.

The advisory listed affected counties as of 10:00 a.m. on May 29, 2026: Alameda, Butte, Contra Costa, Humboldt, Kings, Marin, Mendocino, Merced, Monterey, Napa, Placer, Sacramento, San Joaquin, San Mateo, Santa Clara, Santa Cruz, Shasta, Solano, Sonoma, Stanislaus, Tulare, Yolo and Yuba.

The advisory noted that Costco is not at fault and is cooperating with the response. For next steps and inspection, residents were directed to contact their local county agriculture department.