Napa County Reports Glassy-Winged Sharpshooter Found in Costco Grape Vines

Napa County agriculture commissioner Tracy Cleveland issued an alert on Tuesday after inspectors found the glassy-winged sharpshooter in grapevines sold at Costco Wholesale in Napa. The plants came from Burchell Nursery in Fresno County and were shipped between April 21 and May 26 to Costco locations serving Napa, Sonoma, Marin, Solano and Yolo counties.

Officials said 63 of the 220 grapevines delivered to the Napa Costco have been destroyed after one egg mass was detected. The remaining 157 plants may already be in the hands of customers who purchased them.

The glassy-winged sharpshooter spreads Pierce’s disease, a bacterial infection that blocks water flow in vines and has no known cure. Visible leaf damage often does not appear until late summer, complicating early detection. Cleveland stated that the pest poses a serious risk to local vineyards and urged residents who bought the plants to contact county agriculture officials.

Costco is contacting affected members and cooperating with the investigation.

The glassy-winged sharpshooter was first found in California in 1994. A University of California study estimated that Pierce’s disease caused nearly $30 million in losses and destroyed more than 1,000 acres of grapevines in Northern California between 1994 and 2000.

County officials noted that an established population would be difficult and costly to eradicate and could increase losses for vineyards, wineries and tourism.