On December 18, 2024, the Washington State Department of Agriculture (WSDA), one of the council’s member organizations, announced the successful eradication of northern giant hornet (Vespa mandarinia) from Washington and the United States. 2024 marked the third year of survey with no detections, which is the requirement for declaring this species successfully eradicated.
The eradication success was the result of a multi-year, multi-organization, and multi-country collaboration. Northern giant hornet was first detected in Washington in 2019, when a Whatcom County homeowner found a deceased large insect on their doormat and witnessed similar live insects flying away. Curious about what it was and where it came from, they posted it on Reddit, where community members told them to report it to the Washington Invasive Species Council. The council received the report and immediately forwarded it to state entomologists at the Washington State Department of Agriculture, which responded to obtain the specimen, the first of its kind found in the United States. Northern giant hornet was already a species of concern as part of the council’s and WSDA’s horizon scanning, proof that preparation for potential introductions of new invasive species is of great value.
The response that followed involved extensive collaboration between state, federal, and international government agencies, as well as significant support from state and local communities. An official state survey for the pest was launched in conjunction with community-based surveys, including a search for nest-founding hornet queens by area beekeepers and a statewide citizen science survey, where homeowners created and hung homemade traps and reported findings to WSDA.
These partnerships proved crucial when the eyes of the nation turned to the response effort after a New York Times article about “murder hornets” went viral, and the hornet population in Washington suddenly became a mainstream media and online community sensation. This increased attention from media partners facilitated significant public interest and engagement. The additional awareness of the pest across the state generated thousands of reports of suspected hornets, with the public providing half of the confirmed northern giant hornet detections, including those crucial to detecting and eradicating their nests.
In October of 2020, WSDA found the first known northern giant hornet nest in the United States, using a combination of sophisticated radio telemetry and visual inspection of dense forest. The nest was located inside a hollow dead alder and eradicated by use of carbon dioxide to sedate the hornets, a vacuum for extraction, and sting-proof suits for staff protection. The section of tree containing the nest was removed and the remaining hornets were extracted in a cold facility provided by another council member organization, Washington State University. An additional three nests were found and eradicated in August and September 2021. State and public trapping efforts and surveying continued throughout the following years in Whatcom County until December 2024, when the last trap contents were inspected and no hornets were found.
This successful eradication is a significant victory for native ecology, agriculture, pollinator services, small businesses, recreation, and human health in Washington state—all of which would have been at risk if northern giant hornets had established in Washington State. Horizon scanning, outreach, diligent staff effort, cooperation between multiple organizations and countries, and public engagement combined to successfully eradicate this invasive species from Washington.
WSDA staff opened the section of tree containing the first hornet nest detected in the United States at a Washington State University facility during the COVID-19 pandemic in October 2020. Left to right: Rian Wojahn, Chris Looney, Sven Spichiger, Jessica La Belle, Cassie Cichorz, Karla Salp. Jessica La Belle serves as council staff after being part of the hornet team at WSDA. Photo courtesy of WSDA.