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UC Scientists collaborate to eradicate European grapevine moth from California

The Issue

European grapevine moth (EGVM), Lobesia botrana, considered the most important insect pest of grape in Europe and the Middle East, was first detected in Napa Valley in 2009. The immature stages injure the berry, promoting the development of fungal infections that result in bunch rots. While moth populations were largest in Napa County, by 2011 the moth had also been found in nine other counties as far south as Fresno. If the moth became established it could increase production costs in all grape growing regions, result in economically damaging export restrictions on table grapes, and cause adverse environmental effects if it led to a greater reliance on insecticides. In 2010, the US and California Departments of Agriculture began an eradication program to keep this insect from becoming established.

What Has ANR Done?

UC ANR academics responded rapidly—working with public and private partners and international scientists—to develop a pest management program that relied on a dual approach of deploying pheromone dispensers to disrupt mating and application of carefully-timed insecticides. In late 2009, UC scientists published an extensive literature review describing the current knowledge of life cycle and management on the UC IPM Exotic and Invasive Pests webpage. Next, UC scientists mounted a multi-pronged research program to study the biology, life cycle, host range, and management practices under California conditions. Growers used the information gathered by the UC scientists to monitor and control the pest, and regulators used it to formulate EGVM detection and dispersal regulations. Results demonstrated that low-toxicity conventional and organic insecticides gave excellent control without disrupting the natural biological controls for other grapevine pests, avoiding secondary pest outbreaks. This strategy allowed grape growers to continue to produce a competitive crop under quarantine restrictions. Information generated from field observations, and research trials was reported weekly or semiweekly through UCCE Napa County EGVM newsletter. A summary of the program was published in California Agriculture October/December 2014 issue.

The Payoff

European grapevine moth successfully eradicated as a result of UC collaboration’s response plan

Over the span of seven years, the dual pest management approach was implemented, and EGVM detections declined from over 100,000 moths in 2010 to one moth in 2014 and none in 2015 or 2016. Subsequently, all previous 10 California infested counties have been deregulated, and EGVM declared eradicated from California and the United States. Lifting quarantine restrictions from table grape production areas enhanced the industry’s ability to export its product and preserved community economic wellbeing. This multi-agency collaboration contributed to a successful science-based response plan to a serious pest threat.


Supporting Unit: Statewide IPM Program

Napa and Sonoma Counties were the most affected counties; other counties are Fresno, Mendocino, Solano, Nevada, Santa Clara, Santa Cruz, San Joaquin, Merced
Lucia G. Varela
707 565 2601

Monica Cooper
707 253 4221