Monday July 26, 2010

In an effort to keep European Grapevine Moth from establishing a long-term foothold in Napa County, Agricultural Commissioner Dave Whitmer is asking urban grape growers, including homeowners with a small number of vines and casual growers, to remove the fruit from the vines and dispose of it with other yard waste. About 40,000 post cards with the headline “Kick the Moth Out!” will be mailed to county residents the week of July 26, with more information about the moth. 

“The entire agricultural and viticultural community in Napa County is working together to fight this invasive pest,” Whitmer said. “Vineyard managers, winery viticulturists and Napa County growers  whose livelihoods depend on harvesting their grapes have been treating for the moth with very selective larvicides and using a cutting edge practice called mating disruption, which uses the moth’s own  pheromone to disrupt the insect life cycle. These practices, adapted from science used to combat this pest in other regions of the world, have been employed by local grape growers for the past few months and we are encouraged by the results. 

“However, those efforts could be undone by moths that have infiltrated urban area grapevines. I am asking folks who grow grapes but are not dependent on the harvest to please strip the fruit for this year, which is a very sustainable way to ensure the interruption of the moth’s life cycle.”

Although stripping the fruit is the best way to stop the life of the moth, there are organic and non-organic chemicals that are registered for use on grapes in the urban environment. However, multiple treatments are usually required and must be carefully timed to have full effect. For more information, visit the County Web site at www.countyofnapa.org  or call 1-866-Bug-spot.

The European Grapevine Moth was first discovered in Napa County in late 2009. It was the first time the moth has been discovered in the United States. In other grape-growing regions, including France, Italy and Chile, the moth has become well established and requires vigorous attention and on-going costs to keep it under control. The moth focuses on the flowers and the fruit of grapes and causes significant damages if left unchecked.

For more information, contact Dave Whitmer, Agricultural Commissioner, at 707-253-4357 or Dave.whitmer@countyofnapa.org, or Greg Clark, Assistant Agricultural Commissioner at 707-253-4357 or Greg.clark@countyofnapa.org