Agricultural officials opened a second front Wednesday in the fight against two invasive moth species, one known for the controversy surrounding it, the other a newcomer that already is creating anxiety for its presence in a score of Napa Valley vineyards.
With the western sun sinking low, a federal scientist Wednesday released 3,000 sterile male and female light brown apple moths into a pinot noir vineyard on the Napa-Sonoma border.
The release at one of Domaine Chandon?s vineyards is part of a test to see how the irradiated moths will disperse and how long they survive. If the results are promising, the sterile moths eventually could be used in huge releases in order to keep fertile moths of both sexes from successfully mating.
The fertile males would be ?wasting their time with with a sterile female,? explained Gregory Simmons, an entomologist who coordinates the sterile apple moth program with the U.S. Department of Agriculture.
The test at Domaine Chandon began as officials disclosed the prevalence in the Napa Valley of another exotic pest, the European grapevine moth.
That moth, which has damaged grapes on at least three continents, was first discovered in late September and since has been found on 22 different properties between St. Helena and Napa.
In response, agricultural officials and industry leaders are urging Napa growers to remove any residual fruit and disc it into the ground in order to deprive the pest a sanctuary over the winter.
?This is a pest that can do tremendous damage to the grape crop, so it?s a real threat to our sustainability,? said Bruce Phillips, president of Napa Valley Grapegrowers, which represents more than 500 growers and related businesses.
The find is the first known infestation of the European grapevine moth in the United States. But the pest, Lobesia botrana, has damaged fruit in Europe, the Mediterranean, Russia, Japan, the Mideast, the Near East and Africa.
State and local inspectors placed special traps this fall in Sonoma County near the Napa border, but found no grapevine moths here, said Cathy Neville, Sonoma County agricultural commissioner.
The apple moth, however, triggered a state and federal campaign to prevent it from spreading this fall. About a fifth of Sonoma County?s vineyards were placed under quarantine this season for the apple moth, as well as almost 70 percent of Napa?s vineyards. Growers under quarantine still can move their crops to harvest, but they must show that they aren?t spreading the pest outside the quarantine areas.
Controversy has surrounded the apple moth ever since the state in 2007 conducted aerial spraying over Monterey and Santa Cruz counties with a chemical designed to disrupt the moths from mating. The moth since has been found in 18 counties.
Critics of the government?s efforts insist the apple moth is a minor pest and doesn?t require the $700,000 that the federal government already has spent to develop the sterile moth program, let alone the $75 million in federal funds set aside to fight the pest.
?It?s a waste of taxpayer money,? Yannick Phillips, a Sonoma activist, said of Wednesday?s sterile moth release.
But Josh Rubin, a viticulturist with Yountville-based Domaine Chandon, said the winery welcomed the release of sterile moths in its vineyard. It hopes the test will help develop a means to prevent the moth from becoming established in Wine Country.
Sterile insects, which have proven effective in fighting other pests, could be ?a really good way to control the moth before it becomes a problem,? Rubin said.
Simmons said about 30,000 sterile apple moths could be released in the next month on surrounding lands where growers have given the government permission to use the lands for the study.
Many growers have said the main threat from the apple moth may be the economic damage from the quarantines. In contrast, the grapevine moth worries growers for the damage it can do to their fruit.
In a 10-acre Oakville vineyard, the grapevine moth attacked the berries and infected them with botrytis, also know as bunch rot.
Workers were unable to harvest the grapes there and instead had to strip all the fruit and disc it under, said Greg Clark, Napa County?s assistant agricultural commissioner.
Grapevine moth larvae has been found on a total of 19 properties in the Napa Valley, Clark said. Six adult moths were found on five properties. Three of those properties had both adult moths and larvae.
Most of those properties are near Oakville and Rutherford.
The grapevine moth is about to go into dormancy for the winter, where it will survive as pupae, a pre-adult stage. Inspectors continue to walk through vineyards in search of pupae samples.
Officials also are urging growers to disc under any remaining grapes.
?There is a lot of fruit out there, especially in areas where this moth has been found,? said Clark. Burying that fruit ?would significantly reduce the population that we?re going to have to deal with come spring.?
Phillips said growers will comply by removing the fruit ?because we can?t afford to let this spread to your neighbor?s property and across the valley.?
State and federal officials say they are using the next few months to form plans on how best to fight the pest.
New quarantine rules have yet to be developed, but all the properties with European grapevine moths already are under quarantine for light brown apple moth, Clark said.
Officials plan to begin ?very substantial trapping come spring in Napa and Sonoma counties,? said Larry Hawkins, a spokesman for the U.S. Department of Agriculture.
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