OLYMPIA – After three years without confirmed detections, the Washington State Department of Agriculture (WSDA) and the United States Department of Agriculture (USDA) have declared the northern giant hornet (Vespa mandarinia) eradicated from Washington and the United States.
“We’re pleased to announce the eradication of the northern giant hornet in Washington state,” Derek Sandison, WSDA director, said. “I’m incredibly proud of our team, which has dedicated years of hard work to safeguarding our state and the nation from this invasive threat to our native pollinators and agriculture. I’d also like to acknowledge the federal, state, and local support that made this feat possible. This success is the result of our combined efforts.”
“We are proud of this landmark victory in the fight against invasive species,” said Dr. Mark Davidson Deputy Administrator at USDA’s Animal and Plant Health Inspection Service. “The success of this effort demonstrates what’s possible when agencies and communities unite toward a common goal. USDA played a key role by providing critical funding, technology, personnel and research support, and scientific expertise that helped WSDA eradicate this pest. By tackling this threat head-on, we protected not only pollinators and crops, but also the industries, communities, and ecosystems that depend on them.”
The eradication success was the result of a multiyear effort to find and eradicate the hornets, which began in 2019. It involved extensive collaboration between state, federal, and international government agencies as well as significant support from community members and groups, especially in Whatcom County.
“Without the public’s support for this effort, it is unlikely we would be announcing the eradication of northern giant hornet today,” Sven Spichiger, WSDA pest program manager, said. “All of our nest detections resulted directly or indirectly from public reports. And half of our confirmed detections came from the public. The people of Washington can be proud that we did this by working together.”
Had the hornets become established in the country, they could have posed a significant threat to honey bees and other pollinators and native insects. Northern giant hornets are able to kill an entire honey bee hive in as little as 90 minutes. They also pose a threat to human health as their sting is more dangerous than that of a honey bee.
WSDA staff opened the section of tree containing the first hornet nest detected in the United States at a Washington State University facility during COVID-19. Oct. 2020. Left to right: Rian Wojahn, Chris Looney, Sven Spichiger, Jessica La Belle, Cassie Cichorz, Karla Salp
Kitsap County
A community member reported a suspicious hornet sighting in Kitsap County, south of Port Orchard, in October 2024. WSDA was never able to obtain the hornet. Without a specimen, officials are unable to confirm the presence of a new county record for a species.
“All we can say is that the image appears to be a hornet of some kind. How it came to be in Kitsap County, we don’t know,” Spichiger said.
Although unable to obtain the specimen, WSDA did place traps in the area and conduct outreach to encourage reports of additional suspected sightings. Neither trapping nor outreach yielded additional evidence of hornets in the area. WSDA will conduct trapping in the area in 2025 as a precautionary measure.
A similar situation occurred in 2020 when a single hornet specimen was found in Snohomish County. DNA evidence ruled out that specimen as being related to the Whatcom County detections. No additional hornets were ever found in Snohomish County.
“Luckily, we were already on the lookout for hornets when they showed up in Washington in 2019,” Spichiger said. “Although they are now eradicated from the state, we’ll always be keeping an eye out for them and encourage community members to do the same. They got here once and they could do it again.”
History
The northern giant hornet was first detected in North America in British Columbia, Canada in August 2019 and confirmed in Washington state in December 2019. Although the two detections were close in time and location, DNA evidence suggests there were two different introductions as specimens from each location appeared to originate from different countries.
WSDA found and eradicated a single hornet nest in October 2020 and three nests in August and September 2021. All nests were inside alder tree cavities. WSDA continued state and public trapping efforts through 2024 in Whatcom County. Despite trapping and continued public outreach, no additional hornets were detected in the area.
