California warns invasive vineyard pest is found on Costco grapevines

Some Costco grapevines sold in California should stay out of the ground after inspectors found an invasive insect on plants sold at multiple stores.

The bug, the glassy-winged sharpshooter, can spread a disease that kills grapevines.

According to Berkeleyside, Contra Costa County agriculture officials said the affected plants should not be planted.

"The glassy-winged sharpshooter poses an immediate and serious threat to grapevines and agricultural landscapes throughout Contra Costa County," said Contra Costa County Agricultural Commissioner Matt Slattengren.

What happened?

Five California Costco stores — including locations in Concord, Danville, and Brentwood, along with other Northern California sites — sold grapevines on which the Contra Costa County Department of Agriculture says the glassy-winged sharpshooter was detected.

Officials traced the issue to grapevines shipped from Burchell Nursery in Fresno County. 

Anyone who bought one of the plants after April 21 is urged to contact the county right away and leave the plant where it is, rather than throwing it out.

Authorities say the grapevine should remain unplanted, kept in the pot or container it came in, and separated from other plants.

California classifies the glassy-winged sharpshooter as a regulated pest because it spreads Pierce's disease, a bacterial infection that kills grapevines and can seriously harm vineyards.

Why does it matter?

That is a major concern in a state whose wine industry brings in billions of dollars each year, since a pest that carries Pierce's disease can threaten vineyards across California

Invasive pests can also make their way into home gardens, backyards, and neighborhoods.

A single infected plant moved from a patio to a yard — or from one county to another — could make the pest far harder to trace and contain.

What can I do?

Anyone who purchased a grapevine from one of the affected Costco stores after April 21 should keep it isolated, avoid planting it, moving it, or putting it in the trash, and contact county officials immediately.

Inspect new plants before placing them near your yard or edible garden. Look for unusual insects, leaf damage, or signs of stress, and, when possible, keep new arrivals separated from established plants for a short time.

For ongoing plant care, gardeners can reduce risks by using nonchemical methods first, monitoring plants regularly, and keeping weeds and debris under control.

State and county agencies are coordinating to identify potentially infested plants and keep the pest from becoming established in vineyard regions.

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