“Murder hornets” eradicated in the U.S., agriculture officials say

The Northern giant hornet, more commonly known as the “murder hornet,” has been eradicated in the U.S., agriculture officials said Wednesday.

The ominously nicknamed invasive species was confirmed to be in the U.S. in 2019 after officials in Washington state received and verified two reports of the hornet. Efforts quickly began to track and get rid of them. 

The 2-inch-long hornet, with a stinger longer than that of a typical wasp, can deliver potent venom, but is largely dangerous to bees and other insects, not humans. Eradication efforts started because of the threat the hornet posed to bees and agriculture across the country. 

“By tackling this threat head-on, we protected not only pollinators and crops, but also the industries, communities, and ecosystems that depend on them,” Dr. Mark Davidson, deputy administrator at USDA’s Animal and Plant Health Inspection Service, said in a news statement.

How “murder hornets” were eradicated 

State, federal and international government agencies worked together to eradicate “murder hornets” in the U.S., the officials said. 

To do so, first entomologists had to find the hornets’ nests. Finding the nests can be a challenge, because the hornets typically build their nests in forested areas, often in an underground cavity, according to the U.S. Department of Agriculture. In some cases, entomologists captured a live hornet, attached a radio tag to it, released it, and tracked the hornet back to its nest. Figuring out how to securely attach a radio tag to a hornet without harming it was a hurdle. 

After finding a nest in a tree, a team plugged the nest with foam, wrapped the tree in plastic and vacuumed out the hornets. They also injected carbon dioxide into the tree to kill any remaining hornets.

In 2022, scientists said they were setting about 1,000 hornet traps in Washington. Hornets caught in traps help scientists find the location of nests. The previous year, Washington state officials destroyed a nest, finding nearly 1,500 hornets “in various stages of development.” 

The public also helped officials track down hornet nests. If not for help from the public, there’s a good chance that the hornet could have been around for years to come, Sven Spichiger, Washington State Department of Agriculture pest program manager, said during a news conference Wednesday.

“All of our nest detections resulted directly or indirectly from public reports,” Spichiger said in a press release. “And half of our confirmed detections came from the public.

Could the hornet come back to the U.S.?

While officials in Washington celebrated the eradication of the invasive hornet species, Spichiger acknowledged they could come back to the U.S. He said officials would continue to keep an eye out for the hornet and encouraged members of the community to do the same.  

“They got here once and they could do it again,” Spichiger said. 

CBS News previously reported that it was unclear how the hornets first arrived in the U.S., though invasive species can be “unwitting hitchhikers” on things like shipping containers.

Even now, five years after the hornets appeared in the U.S., Spichiger said officials will never know exactly how they got to the country. 

What makes “murder hornets” unique?

The hornet, an invasive species from Asia, can kill an entire hive of honeybees in as little as 90 minutes, according to agriculture officials. 

“The hornets can enter a ‘slaughter phase‘ where they kill entire hives by decapitating the bees. The hornets then defend the hive as their own, taking the brood to feed their own young,” according to the Washington State Department of Agriculture. “They also attack other insects but are not known to destroy entire colonies of those insects.”

The hornets typically only attack people or pets when threatened, but can sting repeatedly. 

The hornet species has a large orange or yellow head and black-and-orange stripes across its body. 

They were first detected in North America in British Columbia, Canada ,in August 2019, authorities said, and then were confirmed in Washington state by the end of 2019.

When the species first arrived in the U.S., it was known as the Asian giant hornet. But in July of 2022, the Entomological Society of America adopted “Northern giant hornet” as the common name for the species. The organization also adopted the names Southern giant hornet as the name for a closely related species.

“Common names are an important tool for entomologists to communicate with the public about insects and insect science,” organization President Jessica Ware said at the time. “Northern giant hornet is both scientifically accurate and easy to understand, and it avoids evoking fear or discrimination.”

While the U.S. appears to have gotten rid of them, at least for now, scientists in Spain last month reported sightings of the hornet species in Europe. They described two sightings of the hornet in the journal Ecology and Evolution.