Body of News Release
Marin County, CA – Marin County’s Agriculture Commissioner has a message for anyone who recently purchased leafed-out grapevine plants from the Costco in Novato: Call me.
Inspectors from multiple counties in Northern California, including Marin and Sonoma, have found suspected glassy-winged sharpshooter (GWSS) life stages on grape plants shipped from Burchell Nursery’s Fresno location to Costco stores. The GWSS is a destructive insect that sucks the fluids out of plants and can wreak horticultural havoc in agricultural areas.
Marin Agricultural Commissioner Joe Deviney said two samples taken during a recent inspection have been confirmed by the California Department of Food and Agriculture as GWSS nymphs.
“The shipping nursery is required by state quarantine laws to notify our office prior to shipping, and that did not occur,” Deviney said. “All the counties affected are responding with enforcement actions and seizing and destroying the infested plants. Tracking down the locally purchased plants is our goal right now.
“Costco is not at fault here, and they’ve been an exceptional partner throughout this process,” Deviney added. “They acted quickly, cooperated fully, and helped us reach customers as fast as possible. We’re fortunate to have such a proactive retailer working with us to protect Marin’s agriculture.”
To prevent the spread of this pest, anyone who bought leafed-out grapevines from the Novato Costco is asked to call the Agricultural Commissioner’s Office at 415-473-7888 and place two garbage bags over the plants and secure them tightly. Do not place potentially infected plants in a compost bin or garbage container.
This notice applies only to leafed-out grapevines intended for planting, not table grapes sold for eating. Residents should keep the plant in place and avoid moving, transporting, or disposing of it until inspectors can respond. Costco is the only Marin retailer that received plants from this grower.
Deviney’s staff routinely inspects plant shipments coming into Marin to prevent the spread of harmful pests. The GWSS damages a wide variety of plants and spreads lethal diseases to crops such as almonds and grapes for which there are no known cures. The insects are known to feed on at least 250 varieties of plants, including widely used landscape plants, fruits and vegetables. Native to the southeastern United States and Mexico, the glassy-winged sharpshooter has been established in parts of central and southern California since the 1990s.
Deviney said Marin’s inspectors have surveyed all grape plants from earlier Costco shipments as well as other nearby and commingled plants and his staff has increased trapping efforts at the site. Deviney emphasized the wine grape industry and the landscape plant retail business would endure significant damage if the GWSS population were to establish itself in the North Bay. Marin is coordinating closely with state officials and neighboring counties to ensure the pest does not become established in the region.
An adult glassy-winged sharpshooter can drain 200 to 300 times its bodyweight in water every day, the equivalent of a 150-pound adult drinking about 4,300 gallons of water per day. A tree heavily infested with the insect can lose up to 10 to 15 gallons of life-giving fluids per day, requiring a significant increase in irrigation to keep plants healthy.
Anyone who suspects to have seen and captured a glassy-winged sharpshooter can bring contained specimens to the Department of Agriculture, Weights and Measures at 1682 Novato Boulevard, Novato, during regular office hours.
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