In mid-October 2009, European grapevine adult moths and multiple larvae were detected in a vineyard in the Oakville area of Napa County. This was the first known find of this pest in North America. In 2009, approximately 10 acres of vineyard in Napa County had 100% crop loss due to the insect burrowing into the fruit. Feeding damage by EGVM causes severe Botrytis (fungal rot) infections, and larvae in infested clusters leave webbing and excrement in ripening fruit.
Studies of this moth internationally show that larvae feed primarily on the flowers and fruit of grapes and occasionally on the flowers of olive and rosemary. In the absence of these preferred hosts, larvae will feed on the fruit and/or flowers of other plants located nearby, but populations are not known to rise to damaging levels on these plants. If infested grapevines are completely removed, it will move over to a different plant for short period, but it cannot survive without grapes.
EGVM is a significant pest found in Europe, the Middle East, Russia, and northern and western Africa and Japan. In 2008, it was also detected in Chile.
Approximately 40,000 traps were placed throughout California in 2010 to determine if EGVM was present elsewhere in the state. This was a cooperative project between the United States Department of Agriculture (USDA), the California Department of Food and Agriculture (CDFA), and County Agricultural Departments. In 2010, European Grapevine Moth was found in Fresno, Mendocino, Merced, Monterey, Napa, San Joaquin, Santa Clara, Santa Cruz, Solano, and Sonoma counties. Trapping continued in 2011 and EGVM was also found in Nevada County.
The first European Grapevine Moth was found in Sonoma County in the Kenwood area on March 29, 2010. A total of 59 moths were trapped in Sonoma County in 2010. In 2011, the total number of moths trapped in Sonoma County was nine. These moths came from only two sites. No European Grapevine Moths were trapped in Sonoma County in 2012 or 2013. A single moth was trapped in Sonoma County in 2014. ( Trapping Information)
Two moths found within three miles of each other within one lifecycle trigger a quarantine established by USDA and CDFA. Originally, five mile buffers were drawn around each of the find sites. This buffer was reduced to three miles in 2012..
Fresno, Mendocino, Merced, and San Joaquin counties were released from European Grapevine Moth quarantine regulations in February, 2012. The EGVM quarantine was lifted from Nevada, Santa Clara, and Santa Cruz counties in December 2012. At that same time the quarantine areas were significantly reduced in both Solano and Sonoma counties. The remaining quarantine area in Solano County was released from quarantine in 2014. Napa and Sonoma counties currently have areas under EGVM quarantine regulation.