Science

Scientists in Washington state have trapped their first 'murder hornet'

A bottle containing orange juice and rice cooking wine is set as a trap by Jenni Cena, pest biologist and trapping supervisor from the Washington State Department of Agriculture, in an effort to catch Asian giant hornets, also known as murder hornets.
A bottle containing orange juice and rice cooking wine is set as a trap by Jenni Cena, pest biologist and trapping supervisor from the Washington State Department of Agriculture, in an effort to catch Asian giant hornets, also known as murder hornets, on July 29. Asian giant hornets attack and destroy honeybee hives.
Karen Ducey | Getty Images

The Washington State Department of Agriculture announced Friday that it trapped its first Asian giant hornet on July 14, a step forward in the race to remove the invasive species before it damages North American bee populations beyond repair.

"This is encouraging because it means we know that the traps work," Sven Spichiger, the managing entomologist for WSDA, said in a press release. "But it also means we have work to do."

Also known as murder hornets, they are about the size of an average thumb and they have sharp, serrated jaws and stingers that can pierce through denim jeans. It "kind of seems like someone just stitched together a bunch of nightmares and just ran with it," entomologist Samuel Ramsey told NPR's Short Wave in May.

The hornet was sighted for the first time in the U.S. last December, when the state Department of Agriculture verified two reports near Blaine, Wash., close to the Canadian border. It also received two probable, but unconfirmed reports from sites in Custer, Wash., south of Blaine.

According to the WSDA, the hornets could have "negative impacts on the environment, economy, and public health of Washington State." In Japan, they kill up to 50 people a year. Experts are also worried about their presence in North America because they eat bees and destroy their colonies, an alarming development on a continent already grappling with a rapidly declining bee population. When these hornets are finished attacking, they can leave what amounts to piles of bees with their heads torn from their bodies.

Murder Hornets
In this April 23, 2020, photo provided by the Washington State Department of Agriculture, dead Asian giant hornets sit on a researcher's field notebook in Blaine, Wash. The world's largest hornet, a 2-inch long killer with an appetite for honey bees, has been found in Washington state and entomologists are making plans to wipe it out. Dubbed the "Murder Hornet" by some, the Asian giant hornet has a sting that could be fatal to some humans. It is just now starting to emerge from hibernation.
Karla Salp | Washington State Department of Agriculture via AP

While the species is new to North America, bees in the hornets' native habitat in Japan have developed a way to fight back. Murder hornets hunt by sending out a single drone, who scouts potential hives and returns to its colony to recruit more murder hornets to attack the bees. Japanese bees can coax that first scouting hornet inside their colony, where an entire squadron of bees is ready to drop onto the hornet and cover it completely.

"They all start vibrating their flight muscles and they actually create so much heat in this process that they cook the hornet, and the carbon dioxide that's produced in the process also totally can suffocate the hornet as well," Ramsey said. "It's a pretty remarkable ability that they create a convection oven in nature to kill their enemies."

Bees in North America can't do that, though. In the fall, colonies begin reproducing queens and drones, so the WSDA hopes to destroy all of the murder hornets in the area by mid-September to prevent the spread of the invasive species.

Now that the department knows its traps work, staffers are going to search for murder hornet nests using infrared cameras, and place more traps around the area that will keep these trapped hornets alive. If the hornets stay alive in their traps, WSDA researchers will be able to track them back to the colony and eliminate them in one swoop.

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