The discovery of three European grapevine moth has forced a
93-square-mile quarantine of grapes in South County. All bulk
grapes, harvest bins and equipment may not leave the quarantined
area after the Santa Clara County agriculture commissioner
announced an eradication plan today.
The discovery of three European grapevine moth has forced a 93-square-mile quarantine of grapes in South County. All bulk grapes, harvest bins and equipment may not leave the quarantined area after the Santa Clara County agriculture commissioner announced an eradication plan today.
The moths were found near Watsonville Road and Day Road and will be most intrusive to grape growers in that area, as well as residential growers within 400 meters of the epicenter of the infestation.
They were found Sept. 15 and Sept. 17 and their identification has been confirmed by the California Department of Food and Agriculture.
Native to Mediterranean Europe, the European grapevine moth was first found in the United States in September 2009 in Napa Valley. Statewide trapping ensued, and moths have been found in a number of counties, including Sonoma, Solano, Mendocino, San Joaquin, Merced and Fresno. Quarantine restrictions are now in place in each of these counties.
The boundaries of the proposed quarantine in Santa Clara County will generally be Llagas Road in Morgan Hill on the north, Foothill Avenue and New Avenue in Morgan Hill, San Martin and Gilroy on the east, Miller Avenue in Gilroy on the south, and the Santa Clara – Santa Cruz County line on the west. The quarantine will regulate the movement of bulk grapes, harvest bins, equipment and other articles that may harbor European Grapevine Moth.
Grape is the preferred host of European Grapevine Moth. Larvae feed inside the fruit and within the fruit clusters. This causes significant damage to the fruit and exposes it to secondary fungal infections. They are more prevalent in thinner-skinned grape varieties, such as chardonnay, pinot noir and zinfandel.
Noncommercial grapes growing at homes near infested areas also pose a threat for spreading the European Grapevine Moth. Next week, state crews will contact residents to assist in removing and disposing of fruit from home yard grapevines. County biologists are contacting commercial growers in the regulated area to ensure compliance with the quarantine requirements
The European Grapevine Moth typically has three generations per year and is not active in the cool winter months. Larvae from the last generation will overwinter as pupae in protected places, such as under bark, in soil crevices, or in leaf litter. The insect is now completing its last generation of the season and, therefore, most eradication activities will occur next spring.
The California Department of Food and Agriculture quarantined 162 square miles in Napa Valley in March 2010 to stop the spread of the moth. Grapes were still able to be processed on site.
