Winegrape News: Special Edition
August 11, 2010With this edition of the Lake County Winegrape Commission newsletter, we provide important information about the European Grapevine Moth and its impact on Lake County grape growers.
The Comission newsletter is a publication dedicated to keeping our members informed about industry happenings and the Commission's work, meetings, and other events.
You may visit the Lake County Winegrape Commission website, www.lakecountywinegrape.org, for additional information.
As always, you are invited to comment on the newsletter, the website, or any of the programs of the Commission. Call the Commission office, 707-995-3421, or send an email to shannong@lakecountywinegrape.org.
Ag Department Urges All Winegrape Growers to Use Extra Care This Year
By Susan Stout - Contributing writer
LAKEPORT - Lake County is moth free. That's the good news, says Deputy Agricultural Commissioner Kristine Eutenier. However, the detection of the European Grapevine Moths (EGVM) in nearby Napa County is affecting a portion of Lake County; and, the real concern now, says Eutenier, is to keep the potentially devastating pest out of Lake County.
Because two moths were found in Pope Valley in Napa County, a quarantine was imposed to encompass a five-mile radius around the site of the find. That particular five-mile area extended the boundary line into the southern portion of Lake County, Eutenier explained.
As a result, certain growers, harvesters, haulers and receivers within areas under quarantine - including Lake County - must comply with restrictions and rules that have been developed to prevent spread of the EGVM, also known as Lobesia botrana.
"It is important to detect and treat EGVM infestations while their population is still small," states a brochure from the California Department of Food and Agriculture (CDFA). "Grapes are ranked second among agricultural commodities in California. Establishment of this pest could have a significant impact on our vineyards and agricultural economy."
Eutenier is hoping to convince the U.S. Department of Agriculture (USDA) to change the quarantine boundary line that has included Lake County. She would like the USDA and CDFA to consider using the County line as the boundary to the north of the EGVM find in Pope Valley.
Because the lines must follow established roads to delineate the boundaries, the quarantine is pushed out beyond the five-mile radius mark, Eutenier explained. In the case of the north Napa County find, the region between the Pope Valley vineyard site and any vineyard in Lake County is without a "host" plant, meaning it would be almost impossible for moths to make their way from the site to another vineyard in Lake County. "It's mountain range and dry chapparel," she said of the land north of where the moths were found in Napa County. The EGVM flies only about 100 meters, and there must be a host. "They need to eat," said Eutenier.
What you can do to prevent infestation
"Clean everything," she says, emphasizing the word "everything." "Don't let anything on the property without cleaning it." This means every piece of equipment, she added, from the harvester to the bins. "If any equipment is coming from an area where EGVM have been detected, make sure it is clean before it leaves the infested area."
The larvae of the moth presents the most risk because it can be transported easily without detection. The main problem in movement of product is larvae in grapes or the eggs on leaves. Green waste from wineries is a concern, said Eutenier. For that reason, special regulations are in place for green waste disposal from the infested areas.
One of the biggest fears for the County is importation of grapes by the home winemaker. "It's not a problem for those winemakers using their own Lake County grapes," said Eutenier. "It's those (winemakers) who get their grapes from homegrown vines out of the area."
Quarantined Areas
A discovery of two moths in a vineyard near Lodi last week will likely mean a quarantined area of San Joaquin County, also. It is expected to affect 62,000 acres of vineyards, according to reports.
According to the CDFA, the pest was first reported in North America in vineyards of Napa County in September 2009. Following confirmation of the find, the CDFA established the state interior quarantine to restrict movement of host materials and prevent the spread of the EGVM.
The damage can be devastating. Approved treatment identified by the U.S. Department of Agriculture's Animal and Plant Health Inspection Service includes methyl bromide fumigation. In Fresno, the preferred treatment is removal of fruit. Because the larvae feed on flower buds and fruit, damage is both external and internal.
"The EGVM larvae feed directly on grapes. This feeding renders the grapes unmarketable due to direct damage and makes the fruit subject to decay. Establishment of EGVM could impact the quality and productiveness of both homegrown and commercial grapes," the CDFA brochure states.
Information available
To obtain a copy of the CDFA brochure, call the Lake County Department of Food and Agriculture, 707-263-0217, or visit the CDFA website at www.cdfa.ca.gov. A map of CDFA regulated areas is available at www.cdfa.ca.gov/go/egvmq. In addition, Napa County provides weekly updates on biology, monitoring, and management of the EGVM on a website newsletter: Napa County EGVM Newsletter.
Additional Information on EGVM
The following documents (in pdf formats) offer additional information about the European Grapevine Moth and may be of interest to you. Click on the document title to download and view.
Links to Resources