A grapevine-killing pest reached the Ukiah Costco

MENDOCINO CO., 6/1/26 — Plants sold at Costco stores around California this spring, the Ukiah warehouse among them, harbored the glassy-winged sharpshooter — an insect that can spread Xylella fastidiosa, the bacterium behind the vine-killing Pierce’s disease. On May 19, inspectors seized and destroyed what was still on the shelves, but the rest had already gone home with shoppers, scattered in backyards across Mendocino County and into Lake County. The state has no sure way to find them.

The Ukiah store may have sold more of them than anywhere else.