Invasive pest found on Costco plants a threat to California Wine Country vineyards, officials warn

Authorities in Northern California alerted residents on Tuesday about an invasive species found on plants from Costco that could threaten the region's vineyards and other agriculture in the region.

The Solano County agricultural commissioner issued a consumer alert "urgently asking residents to take immediate action" after  glassy-winged sharpshooters were found on grapevines and citrus plants delivered to Costco stores. There are three Costco stores in the county, in Fairfield, Vacaville, and Vallejo.

"Glassy-winged sharpshooters pose a serious and immediate threat to vineyards, agriculture, and backyard plants throughout Solano County and surrounding regions," Solano County Agricultural Commissioner Ed King said in a statement. "These insects spread the bacterium that causes Pierce's disease, which can kill grapevines and severely impact vineyards. Community cooperation is critical right now."

King urged anyone who recently purchased grapevines or citrus plants from Costco since April 21 to contact the county's Agriculture Department immediately at 707-784-1310 or AGcomm48@SolanoCounty.gov so staffers can contain and eliminate the threat. 

Residents were directed to place two garbage bags over grapevines to secure them tightly. For citrus plants, people were asked to contact the department to schedule an inspection. The department urged resident not to return, relocate, or give away the plants, and not place them in trash bins or compost containers. 

The glassy-winged sharpshooter (Homalodisca vitripennis) is a large leafhopper insect native to the southeastern United States. First detected in California in the late 1980s, it has since become one of the state's most significant agricultural threats for its role as a vector for a deadly plant bacterium that causes Pierce's disease which fatally dehydrates grapevines. 

The glassy-winged sharpshooter flies higher and farther that native sharpshooters, and can thrive in commercial citrus orchards often planted right next to vineyards. The Xylella fastidiosa bacterium it spreads can also causes diseases in other major California crops such as almonds, alfalfa, peaches and plums, as well as a wide range of plants used in residential landscaping, according to University of California researchers.