(Wines&Vines) - At the recent Vineyard Economic Seminar, Greg Clark, the assistant agricultural commissioner for Napa County, described how local growers, ag advisors and agricultural regulators joined forces to defeat one of the biggest threats to grape crops in the county and the state, the European grapevine moth. The withering of Chardonnay berries was first documented mid-September 2009 in a vineyard on Money Road in Oakville, Calif. Samples were collected, larvae found, and the culprit was positively identified by CDFA/USDA as Lobesia botrana—the European grapevine moth—that same month. It was the first discovery of the pest in North America. By the end of October, the entire 11-acre Chardonnay crop, an estimated 65 tons of grapes valued at $163,816, was lost. The total loss to the winery, however, was $1,045,200, the potential value of wine, and this was just for a single property.