Move over, apple moth. There’s a new vineyard pest atop the most-wanted list: the European grapevine moth.
One of the grape-threatening insects was found in a trap last week in Kenwood. Agencies including the Sonoma County Agricultural Commissioner’s Office have increased the number of traps in a three-mile radius around the Kenwood find. If two moths are found within three miles of each other within one lifecycle, a federal quarantine will be imposed.
“I’m very concerned, and the growers are concerned,” said Cathy Neville, Sonoma County’s agricultural commissioner, but “I think it’s controllable.”
The pest causes severe fungal rot, and larvae ruin ripening fruit. In 2009, approximately 10 acres of vineyards in Napa County – the first infestation in North American — had a 100 percent crop loss due to the insect burrowing into the fruit.
Neville said that procedures established to deal with the apple moth should make compliance with a quarantine, if it comes, much easier. “It set the stage,” she said. “Now we know ‘this is how you handle a quarantine.’”
Neville said her office is meeting with growers to educate them on the new threat. A countywide meeting of grape growers is set for April 16.
As of March 31, 2010, there have been 137 European moths or larvae found in Napa County, nearly all of which is under quarantine. State rules call for all lands within three miles of an infestation to fall under quarantine.
“This is an invasive moth, something that doesn’t belong in Napa County or anywhere in this country,” said David Whitmer, Napa’s agriculture commissioner. “We’re doing all we can, working with our state and federal partners, to track this pest and determine our response as quickly as possible.”
Studies of this moth in other countries show that larvae feed primarily on the flowers and fruit of the grape, and they can also feed on number of other hosts, including olives, blackberries, cherries, nectarines, persimmons and pomegranates. If infested grapevines are completely removed, the pest will move over to a different plant for short period, but it cannot survive without grapes
According to the Sonoma agriculture commission, the movement of equipment between Sonoma and Napa counties increases the likelihood of transferring the pest and starting an infestation in Sonoma County. Four thousand traps have been placed throughout commercial vineyards in Sonoma County, and some deployed 50,000 statewide.
The European grapevine moth is part of the same family as the light brown apple moth. The growing concern over the European variety comes just after a major policy shift on the light brown apple moth.
The United State Department of Agriculture in March found that eradication in California is not currently feasible due to increase in light brown apple moth populations. The state has therefore ruled out aerial treatments and will rely on the use of pheromone twist ties and the release of sterile moths.
This marks a significant change in direction which vindicates questions and criticisms voiced for more than two years, said Assemblyman Jared Huffman. “Despite the growth of the LBAM population, there has been no credible evidence of crop damage. California has limited resources, and there are other invasive species that pose real threats to agriculture and deserve our attention.”
