To stop the glassy-winged sharpshooter from spreading a fatal grapevine disease into Northern California, the Pierce’s Disease and Glassy-Winged Sharpshooter (PD/GWSS) Board at the California Department of Food and Agriculture committed $820,000 to the ongoing emergency response.
Preventing the glassy-winged sharpshooter from becoming established in new areas protects winegrapes and other agricultural and landscape plants. California’s wine industry generates about $73 billion in annual economic activity and supports more than 422,000 jobs statewide. A 2025 economic study estimated that if glassy-winged sharpshooters spread unchecked, outbreaks of Pierce’s disease could cost winegrape growers an additional $56 million a year in lost production and vine replacement.
Since May, county agriculture officials have been tracking down nearly 10,000 grapevines from a Fresno nursery that may have carried the invasive pest into 40 counties. The Board’s special emergency funding is intended to support those efforts. Officials have contacted more than 3,100 customers who purchased the grapevines, inspected and/or destroyed more than 2,900 plants and set more than 2,700 additional insect traps.
Glassy-winged sharpshooters have been found on customer plants in 23 counties. Inspections and trapping must continue for at least three years to track if the pest spreads beyond customers’ properties.
“California’s winegrape industry is facing some of the hardest economic times in a generation, but we recognize what is at stake if this destructive pest becomes established in Northern California,” said Board chair Trey Irwin. “Putting $820,000 from the Board’s limited reserves toward this effort is a major commitment for our industry and shows how seriously we’re taking this threat.”
The funding comes from assessments paid by California winegrape growers to support pest and disease research and prevention. Since 2001, the Board has invested $99 million in research, outreach, prevention and control for Pierce’s disease, grapevine viruses and the insects that spread them.
“It is important that we continue with inspections and trapping to closely monitor the situation,” said Michelle Pham, response lead with the CDFA Pierce’s Disease Control Program. “This effort depends on close coordination among growers and county, state and federal agencies. For 25 years, that partnership has helped keep the glassy-winged sharpshooter from spreading throughout California.”
People who suspect they have found a glassy-winged sharpshooter should contact their local agricultural commissioner’s office (bit.ly/CountyAg). For pictures of the pest and for more information, visit bit.ly/GWSS-Costco.
