Aug 23, 2016

European grapevine moth eradicated from California

Agricultural officials from the California Department of Food and Agriculture (CDFA) and USDA, in cooperation with county agricultural commissioners, have declared the European grapevine moth (EGVM) eradicated from California and have lifted quarantine restrictions.

The EGVM was first detected in Napa County in 2009 with subsequent detections and quarantines in the counties of Fresno, Mendocino, Merced, Nevada, Santa Clara, Santa Cruz, San Joaquin, Solano and Sonoma in 2010, 2011, and 2012.  No EGVM have been detected in California since June 25, 2014.

The infestation peaked in 2010 when more than 100,000 EGVM were detected.  Following an intense period of coordinated trapping, treatments and other detection and response activities, the detection numbers dropped dramatically to 144 detections in 2011. As a result of the collaborative efforts between, USDA, CDFA, county agricultural commissioners, grower liaisons, University of California Cooperative Extension and especially growers, the quarantine area in California shrunk quickly from a high of 2,334 square miles in 2013 to 446 square miles in 2014.

The EGVM, or Lobesia botrana, is originally from southern Europe. The pest primarily damages grapes, but has also been known to feed on other crops and plants.  First and second generation larvae feed on flowers and developing berries in the spring and summer.  Third generation larvae occur in August and September and cause the greatest damage by webbing and feeding inside berries and within bunches, which become contaminated with frass.  Feeding damage to berries also exposes them to infection by Botrytis and other secondary fungi