Moth quarantine still in effect in northern Sonoma Valley
Funds are needed to continue eradication efforts
Grower George MacLeod inspects a European Grapevine Moth trap on his property. Kenwood is part of an area still under quarantine for the pest.
The battle against the European Grapevine Moth (EGVM) has been going well since the bugs were discovered in Napa in 2010, but there are still 5,600 acres under quarantine in Sonoma County, almost all of them in the upper Sonoma Valley along the Napa county line. While all the current known infestations are in Napa, the quarantine area extends in a circle three miles from each infestation site, often extending into Sonoma.
A year ago, Sonoma, Napa, Solano and seven other counties were under quarantine, with affected growers having to trap, identify, and treat affected areas. All grapes transported out of the affected areas were subject to inspection and certification.
An aggressive program of trapping male moths – largely funded by state and federal agencies – was set up in 2010 and allowed growers to identify where the infestations were happening and to selectively spray or deploy more organic methods to get rid of the pest.
Today, only Napa, Sonoma and Santa Cruz counties are under quarantine.
While many pests establish themselves, like the Light Brown Apple Moth, there seems to be a good chance that with continued vigilance and vigorous participation in the current plan, the EGVM infestation can be beat for the foreseeable future. The main ingredient is money. Given the current financial stresses in Washington, a lot of affected people are worried that funding for the program could dry up next year.
California’s Congressional members and industry lobby groups like the California Grape Growers Association have already asked the United States Department of Agriculture to provide $6.5 million to continue the eradication program. According to Rep. Mike Thompson’s office, the USDA contributed nearly $17 million in 2011 and $8 million in 2012 to eradicate the EGVM throughout the state. Thompson is a co-founder of the Congressional Wine Caucus which advocates for the wine industry in Washington.
Locally, the trapping survey program is run by the Sonoma County Agricultural Commissioner’s Office, with the current season starting Feb. 14. Commissioner Tony Linegar says the EGVM may affect Sonoma growers for years to come.
“Even if the quarantine were dropped in Sonoma County, Napa will be there for some years,” Linegar said. “We receive a lot of fruit from Napa, about 450 shipments of wine grapes [came to Sonoma] from Napa county quarantine areas.”
The good news is that there have been no new EGVM findings in Sonoma for nearly a year, Linegar said, and Napa has only found 15 in five or six locations. Unfortunately, several of those locations are near the Sonoma county line, so the quarantine continues to be in effect in parts of Sonoma Valley within three miles of those finds.
The cost of dealing with the quarantine has been significant to local growers in Napa and Sonoma. Thompson cited a figure of $37.2 million for Napa growers; no figures were immediately available for Sonoma County grape growers.
A good deal of the cost to farmers relates to “slack fill” bins, where the harvest bins used in the fields could not be filled to the top to prevent possibly infected grape bunches from falling off the transport trucks. This requires significantly more labor to bring in the crop. And since last year was the biggest crop in the county’s history, that was an appreciable extra labor cost.
“Other costs (are) treatment of vineyards, pesticides, workers, and sanitizing equipment,” Linegar added.
Sonoma County has an $800,000 contract with the California Department of Food and Agriculture to place and monitor moth traps, and is still negotiating for money to oversee enforcement and monitoring of the slack fill and equipment cleaning process. The total could come to $1 million for the 2013/2014 fiscal year, Linegar said.
“Mechanical harvesters can move the moth,” Linegar said. “This played a significant role in the movements of the pest from Napa to Sonoma.” He said that there are 37 vineyard management companies that work in both counties, moving equipment and people back and forth daily. “There’s an ongoing threat of reintroduction.”
The Ag Commission is holding a one-day workshop for growers and vineyard managers at the Kenwood Firehouse on May 1. “We will go over the requirements for handling fruit, and urge them to stay diligent,” Linegar said.
EGVM larvae are deposited in young grape clusters. “Once it gets established, it ruptures the berries. The released sugar gets botrytis – a mold.” Entire crops were lost to the first onset of the pest in Napa.
For 2013 the total cost statewide of managing this pest will be $8.2 million, with California providing $1.7 million, and the USDA the remaining $6.5 million. Growers receive $68.62 per acre sprayed per year under the National Resources Conservation Service program and have to file paperwork to get the funds.
According to the county crop reports:
• In 2010 in Sonoma, 6,244 traps were set out for invasive pests, including several types of fruit flies, gypsy moths, Japanese beetles, EGVM, the Light Brown Apple Moth, and the Glassy Winged Sharpshooter. There were 59 confirmed EGVM captures in the county. There were 2,227 premise visits resulting in inspection of 33,338 shipments of plant material.
• In 2011, 8,441 traps were set out with only nine confirmed EGVM finds. There were 2,245 premise visits that involved inspecting 32,263 shipments.
• The 2012 crop report is not yet available.
In 2013, trapping will be at a density of 100 traps per square mile in commercial vineyards within the quarantine area. Expect to see a lot of inspectors in the area this year. The rest of the county’s commercial vineyards will have 25 traps per acre.