The northern giant hornet has been eradicated, the Washington State Department of Agriculture and USDA announced Wednesday, celebrating fending off a pest that slaughters pollinators and has reportedly killed people.

A live northern giant hornet hasn’t been confirmed in Washington or anywhere else in the U.S. for three years, the threshold for declaring an invasive insect eradicated.

The hornets were formerly called Asian giant hornets and are nicknamed “murder hornets.” WSDA entomologist Sven-Erik Spichiger said he was worried when they popped up five years ago in northwest Washington.

“I have to tell you as an entomologist … it is a rare day when the humans actually get to win one against the insects,” he said.

Northern giant hornets drew worldwide attention in 2013 by reportedly killing 42 people and injuring 1,675 in China. The hornets were detected in North America six years later in Whatcom County and British Columbia.

Queen hornets, hibernating for the winter, likely were stowaways in someplace warm and dry, like a shipping container, Spichiger said. “We are never going to know how exactly they got here,” he said.

Researchers concluded the Pacific Northwest has the perfect climate for the non-native species. Spichiger said he was concerned in 2020 because two beekeepers had encountered the hornets.

“It is a very difficult task to eradicate an insect once it has become well established, and these were established enough to be attacking resources,” he said.

WSDA asked the public to trap for hornets and report sitings. After some trial and error, WSDA was able to track hornets to their nests in the cavities of alder trees.

WSDA destroyed four hornet nests, all in Whatcom County. The last nest was destroyed in 2021. No hornet has been detected in Canada since 2020.

Spichiger credited public vigilance as the primary reason for the successful eradication campaign. The department received reports of thousands of suspected sightings.

“A small population of hornets trying to establish here really couldn’t do it in secret,” Spichiger said.

“Every time a hornet was flying around and visiting someone’s window, we got a call about it,” he said. “That helped direct us to the nests and take them out.

“The fact of the matter is, if the entire community hadn’t stood up and taken action, there is a real good chance that we’d all be living with northern giant hornets for years to come,” he said.

All live northern giant hornet detections have been in Whatcom County. A dead northern giant hornet was found in 2021 in Snohomish County to the south.

WSDA received a photo in October of what looks like a long-dead northern giant hornet on a windowsill in Kitsap County.

The department has been unable to contact the homeowner to collect the specimen. “We have done everything we possibly can,” Spichiger said.

The department set up traps in the area, but haven’t caught any northern giant hornets.

WSDA will continue to watch for northern giant hornets and other invasive hornets, Spichiger said. “We won this battle. We will continue to be vigilant. We have to keep on guard.”

Yellow-legged hornets, another species native to Asia, were detected for the first time in the U.S. in 2023 in Georgia and South Carolina. Although smaller than northern giant hornets, yellow-legged hornets are a menace to bees and people.

“I’m hoping the folks in Georgia and South Carolina have the same kind of luck we did,” Spichiger said.