As the spring weather warms up and European grapevine moths emerge after a long winter, the invasive pest is increasingly turning up in traps that have been set throughout the state. These detections have resulted in the addition of portions of Fresno and Mendocino counties to the EGVM quarantine, and they have also expanded existing quarantine areas in Napa, Sonoma and Solano counties.
"We have set an array of more than 40,000 traps statewide to determine exactly where the infestations exist," says CDFA Secretary A.G. Kawamura. "Detecting the pest is an important first step toward controlling it, and quarantines are the next step in the process. These regulations allow us to protect surrounding uninfested areas by preventing movement of the insects on crops, harvesting equipment and related articles."
Previously quarantined areas in Napa, Solano and Sonoma counties are expanding by approximately 827 square miles. New quarantine areas are being created in Fresno County (approximately 96 square miles) and in Mendocino County (approximately 140 square miles). The state's total EGVM quarantine area now stands at approximately 1395 square miles. Maps are at: http://www.cdfa.ca.gov/phpps/PE/InteriorExclusion/egvm_quarantine.html
The quarantines primarily affect farmers as well as those who harvest, transport and otherwise process or handle crops. Agricultural officials have already begun the process of informing those involved in the industry of the requirements.
Homeowners, plant nurseries, landscapers and other citizens and businesses who work with plants are also involved in the quarantine, though. For example, residents who have grapes, stone fruit trees (peaches, plums, etc.) and other "host plants" for this pest in their yards are asked to harvest and consume their fruit on-site to further limit the risk of spreading the pest.
Residents of the quarantined area are asked to review the list of host plants/fruits (below) and to not remove them from their property; the produce may, however, be harvested and consumed on site.
Kiwi fruit or Chinese Gooseberry
Old-Man's-Beard or Traveller's Joy
False Baby's Breath or White Bedstraw
St. John's Wort or Aaron's Beard
Stone Fruit (e.g. apricot, cherry, plum)
DuPont Crop Protection has issued 2(ee) recommendations for control of EGVM. Growers in California, Oregon and Washington can now use both DuPont Altacor insect control and DuPont Avaunt insecticide for EGVM control.
First- and second-generation treatments may be warranted because this is a newly introduced pest. Altacor (IRAC group 28) is recommended for use on first generation (May – June) followed by Avaunt (IRAC group 22) in the second generation.
To view the 2(ee) recommendation for Altacor click here.
To view the 2(ee) recommendation for Avaunt click here.
EGVM, or Lobesia botrana, is found in southern Asia, Japan, Europe, North Africa, Anatolia, the Caucasus and in South America. The pest primarily damages grapes, but has also been known to feed on other crops and plants.
The EGVM larvae, not the adult moths, are responsible for the damage to grapes. Larvae that emerge early in the spring feed on grape bud clusters or flowers and spin webbing around them before pupating inside the web or under a rolled leaf. If heavy flower damage occurs during this first generation, the affected flowers will fail to develop and yield will be reduced. Second-generation larvae enter the grapes to feed before pupating in the clusters or in leaves. Larvae of the third generation - the most damaging - feed on multiple ripening grapes and expose them to further damage from fungal development and rot. These larvae overwinter as pupae in protected areas such as under bark, and emerge as adults the following spring.