05/27/2026
IMPORTANT ALERT: If you purchased grape plants at the Eureka Costco store, please double-bag the plants with garbage bags, seal the bottom, and report it to the Humboldt County Agriculture Commissioner's office by phone at 707-441-5260 or email at [email protected]. Please read the press alert below for more information about this destructive invasive pest.
⚠️ IMPORTANT AGRICULTURAL ALERT: Residents Urged to Report Possible Invasive Pest on Grape Plants Sold at Costco ⚠️
The County of Humboldt’s Agriculture Commissioner is urging residents to take immediate precautions after the invasive glassy-winged sharpshooter (GWSS) was discovered on grape plants sold at Costco stores throughout California.
The Costco store in Eureka, located at 1006 W. Wabash Ave., was among those that received these grape plants from Burchell Nursery, a wholesale nursery located in Fresno County. The issue occurred at the nursery supplier level, and the local food supply has not been affected by the discovery of this insect.
The glassy-winged sharpshooter, a type of leafhopper, spreads Pierce’s disease which kills grapevines and can also harm almond, citrus and ornamental plants, creating a serious risk for agriculture and home gardens in Humboldt County and across the state. There is currently no known cure for Pierce’s disease. Due to the clear and present danger the pest and disease pose to local vineyards and backyard growers, it is important that any potentially affected plants are inspected as soon as possible.
𝗪𝗵𝗮𝘁 𝗧𝗼 𝗗𝗼
Early detection is critical for protecting Humboldt County and California’s agricultural and natural resources. Anyone who purchased grape plants from the Eureka Costco location on or after Tuesday, April 21 should contact the Humboldt County Agricultural Commissioner’s office to help stop the pest from spreading further.
Please do not plant your recently-purchased grapevine if you have not already done so. Residents who purchased grape plants from Costco on or after April 21 should not move or throw away the plants. Residents should place two garbage bags over the plant, secure them tightly and immediately contact the Humboldt County Agricultural Commissioner’s office for further guidance and to schedule an inspection.
You can reach the Agriculture Commissioner’s office on the phone at 707-441-5260 or by email at: [email protected]
𝗠𝗼𝗿𝗲 𝗜𝗻𝗳𝗼𝗿𝗺𝗮𝘁𝗶𝗼𝗻
Humboldt County has a restriction against the glassy-winged sharpshooter to protect both commercial growers and home gardeners. Native to the southeastern United States and Mexico, this invasive species was first identified in California in the 1990s and is now established in central and southern parts of the state. This pest threatens California’s grape industry and is known to feed on more than 250 plant species, causing damage to vineyards and ornamental landscapes. As part of the Humboldt County Agriculture Department’s Pest Detection Program, yellow panel sticky traps are placed at nurseries and throughout the county to detect the presence of this pest, which has never been detected in Humboldt County.
“The glassy-winged sharpshooter poses a serious threat and it’s important that we move quickly to prevent it from spreading," said Humboldt County Agricultural Commissioner Weylan Shaw. “Staff is working closely with Costco and our state and local partners to protect Humboldt's farms, home gardens and landscapes. If you purchased grapevines from Costco on or after April 21, please contact us. We know this may be an inconvenience and we truly appreciate your help to keep Humboldt's agriculture and gardens healthy."
Additional information about the glassy-winged sharpshooter and Pierce’s disease can be found at the California Department of Food & Agriculture’s website:
cdfa.ca.gov/pdcp/
Photos of the GWSS can be found at:
cdfa.ca.gov/pdcp/Glassy-winged_Sharpshooter.html
📸 Pictured: Symptoms of Pierce's disease caused by GWSS on a grape leaf. Picture from University of California, courtesy of the California Department of Food & Agriculture. Additional text states, "County of Humboldt press release."
UC Cooperative Extension - Humboldt/Del Norte Counties
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