State Agricultural Officials have reported the spread of the European Grapevine Moth to at least six counties in Northern California including Sonoma and Napa. The spread of the pest, which feeds on grape flowers and fruit, has been a constant problem in vineyards and farmland throughout California wine country. The most likely cause of the moth's contact with other counties is due to the transfer of farm equipment, trucks and other materials by people.
Most areas where the moth has been trapped have been under quarantine until the spread of the pest can be stopped. Napa County vineyards have adhered to a strict quarantine that began in 2009 which includes spraying down tractors and other agricultural equipment before leaving a vineyard and combating the pest with ground-level spraying and pheromone-laced twist ties. The ties confuse male moths by making it hard for the insect to breed.
Since the discovery of the the pest in Napa County, trapping of the moth have shown fewer numbers breeding in the region. The University of California Cooperative reports that this could be great news for the California wine and farm industry. The information gathered by the University of California Cooperative and the Napa County Agricultural Commission prove that the multifaceted quarantine measures Napa County has used may be working. Although more testing is still necessary before an official quarantine plan can be used throughout the state many farmers are already using some of the information Napa County has shared.
