No grapevine moth in Washington
State agricultural officials report no detection of European grapevine moth from two years of trapping.
European grapevine moth was found in the United States for the first time in 2009 in a California Napa Valley vineyard.
University of California
While Washington remains free of a destructive moth with potential to damage Washington State’s grape and wine industries, based on two years of trapping results, state and federal officials are making progress in eradicating the pest in California.
The European grapevine moth, found around the world, only recently made its debut in the United States. It was found for the first time in California’s Napa Valley in 2009, and has since spread to several central California counties. An isolated detection on ornamentals was found in Oregon’s Willamette Valley, according to Dr. Doug Walsh, Washington State University entomologist.
The 2011 grapevine moth survey program, led by Washington State Department of Agriculture officials, involved placing and monitoring more than 900 traps and pheromone lures in 16 counties from late June through late September. Traps were monitored bi-weekly.
Trap deployment focused on commercial wine and juice grape vineyards, non-commercial, residential grape vines in populated areas, abandoned vineyards, and feral, roadside grape vines, according to WSDA’s survey report.
“These types of hosts were targeted because they represented the greatest risk of pest introduction and propagation,” said Mike Klaus, WSDA pest survey coordinator for eastern Washington. “We want to detect it as early as possible if it does arrive. If the grapevine moth were to become established here, it could pose a serious threat to our grape and wine industries.”
The adult European grapevine moth, a quarter to a third of an inch long, has mosaic patterned wings. In California, the first-generation larvae web and feed on flower clusters in May and June. The second-generation larvae, from July to August, feed on green berries and enter fruit.
Greatest damage to the grapes is done by the third-generation larvae, which feed inside berries and within clusters, contaminating the cluster with frass (excrement). Feeding on the berries also exposes the fruit to infection from Botrytis cinerea and secondary fungi.
State and federal officials are making progress in eradicating the moth in California. On March 8, the U.S. Department of Agriculture declared eradication of the moth in four counties (Fresno, Mendocino, Merced, and San Joaquin), lifting the counties from quarantine regulations in place since 2010. In Napa Valley, an area still under quarantine and control requirements, USDA and state agricultural officials have reduced the overall regulated area surrounding moth infestation sites from a radius of five miles to three.
Additionally, USDA announced in late February that $8 million in emergency funding would be available to prevent the spread of the moth in California.
The Washington survey was funded by the WSDA Specialty Crop Block Grant Program. WSDA’s trap and pest detection programs include gypsy moth, apple maggot, sudden oak death, spartina, Mediterranean snail, and Japanese beetle.
For more information about European grapevine moth, visit the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service Web site at: www.hungrypests.com.