Information provided by UC Master Gardeners of Monterey, San Benito & Santa Cruz Counties.  Lea este artÃculo en español aquÃ.
Did you purchase a grapevine from Costco this spring? Take a closer look before planting.
The California Department of Food and Agriculture (CDFA) recently reported that glassy-winged sharpshooters, an invasive pest that can spread the bacterium responsible for Pierce’s disease in grapevines, were found on plants sold at some Costco locations.
If you purchased grapevines from Costco between April 21 and May 19, do not move, dispose of, or plant them until you check the latest guidance.
The California Department of Food and Agriculture (CDFA) and county agricultural officials are responding after glassy-winged sharpshooters (GWSS) were found on grapevine shipments sold at select Costco locations in Northern California between April 21 and May 19.
The glassy-winged sharpshooter (Homalodisca vitripennis) is an invasive insect that feeds on many types of plants. It is a serious concern because it can spread Xylella fastidiosa, the bacterium that causes Pierce’s disease, a fatal disease of grapevines.
Why does this matter?
Early detection is critical. Preventing glassy-winged sharpshooter from spreading helps protect home gardens, local landscapes, and California agriculture, including vineyards.
What should you do if you purchased one of these plants?
If you purchased a grapevine from Costco between April 21 and May 19:
• Keep the plant isolated and away from other plants
• Do not plant it if it is still in a container
• Do not move it, return it, compost it, or place it in the trash
• Contact your County Agricultural Commissioner’s Office for guidance
Agricultural inspectors can help identify the pest and provide instructions for safe handling.
What does glassy-winged sharpshooter look like?
Adult glassy-winged sharpshooters are about ½ inch long, dark brown to black insects with partly transparent wings. Eggs are laid in groups on the underside of leaves and may appear as small greenish blisters or tan/brown scars after hatching.
Learn more:
Salinas Valley Agriculture Response
UC IPM Glassy-Winged Sharpshooter Information
GWSS Identification Brochure (English)
Folleto de identificación de la chicharrita de alas cristalinas (español)
If you think you have found glassy-winged sharpshooter, do not move the plant. Note where and when it was found and contact your local County Agricultural Commissioner.