US lawmakers are calling for emergency funding to protect California’s wine industry from the glassy-winged sharpshooter, known to spread the bacterium causing Pierce’s disease.

In a letter to US Agriculture Secretary Brooke Rollins, the lawmakers urged the “immediate” release of $32.2m of federal funds to “contain and eradicate” the invasive pest.

Failure to act quickly carries “significant economic stakes” for California agriculture, warned Senators Alex Padilla and Adam Schiff and Representatives Mike Thompson and David Valadao.

If approved, the emergency capital will finance tracing, surveying, and trapping programmes over the next three years.

Pierce's disease represents a threat to viticulture because it has no known chemical cure. The underlying bacterium, Xylella fastidiosa, invades and clogs the water-conducting xylem vessels of the plants, ultimately killing the vines through severe dehydration and water stress.

University of California research indicates that wine varieties like Pinot Noir and Chardonnay are highly susceptible to the pathogen.

The call for funding comes after the California Department of Food and Agriculture and the Fresno County Agricultural Commissioner’s office discovered infested nursery stock on 19 May, distributed to several Costco locations in northern California.

Impacted Costco sites span major winegrowing regions, like Napa, Mendocino, Monterey, and Santa Cruz.

The infected vines were subsequently purchased by consumers and are now suspected to have spread to residential properties across at least 38 counties.

“The movement of infested nursery stock into and near key grape-producing regions, including areas critical to California’s winegrape and fresh table grape production, significantly elevates the urgency of this response,” the letter read.

California cultivates 99% of all table grapes grown in the US. Estimates by the CDFA reveal that failing to halt the infestation could result in annual agricultural losses eclipsing $104m.