Invasive ‘murder hornets’ eradicated in the U.S., officials say

After three years without confirmed detections, the Washington State Department of Agriculture and the United States Department of Agriculture 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,” said Derek Sandison, WSDA director. “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.”

The northern giant hornet, which quickly became the sensation of the newest “apocalyptic crisis” in 2019 after detection in North America and Canada, circled the media, earning the misnomer “murder hornet.” The northern giant hornet and the Asian giant hornet are the same species, but the Entomological Society of America adopted the name northern giant hornet in July 2022. The 2-inch-long hornets bear a stinger longer than other wasps and, with their potent venom, pose a threat to bees as the hornets can kill an entire hive.

“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. “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 resulted from a multiyear effort to find and eradicate the hornets, which began in 2019. State, federal, and local agencies worked together to eradicate the invasive species in the U.S. by finding the hornets’ nests, plugging them with foam, wrapping the trees in plastic, and then injecting carbon dioxide into the tree and vacuuming out the hornets. 

Because the hornets build nests in forested areas, often in underground cavities, entomologists were often able to track down nests by tagging a life hornet with a radio tag and tracking it back to its nest. 

In 2022, scientists deployed approximately 1,000 hornet traps across Washington to help pinpoint the locations of nests. These traps play a role in tracking hornets and identifying their colonies. The previous year, state officials eradicated a nest containing nearly 1,500 hornets at various developmental stages.

Public involvement was instrumental in locating these nests. Without community assistance, the hornets might have remained a persistent threat for years, according to Sven Spichiger, the pest program manager for the Washington State Department of Agriculture, who shared this insight during a news conference on Wednesday.

“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.”