Sunday, September 20, 2020
Sept. 20, 2020

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Painful sting, Asian giant hornets aren’t big killers

Experts say hornets’ health impact on humans overblown

By , Columbian Features editor
10 Photos
Asian giant hornet.
Asian giant hornet. (Contributed by Washington State Department of Agriculture) Photo Gallery

Asian giant hornets have captured our imagination, and people are spotting them everywhere. Or at least they think they are.

Reports of Asian giant hornet sightings from all around — even Clark County — have swarmed the Washington State Department of Agriculture since news broke that the insects reached the United States in December. Except for five confirmed sightings and one trapped in the state’s northwestern corner, all the rest have been cases of mistaken identity.

“We don’t have any confirmed reports down in the Vancouver area,” agriculture department spokeswoman Karla Salp said.

Most reports haven’t included enough information for the state to investigate. A state entomologist evaluated a dozen complete reports (with photos) from Clark County, and determined the insects were actually bumble bees, various kinds of wasps, cicadas and Jerusalem crickets, according to the department’s online map of sightings.

Little wonder we are riveted by the threat of invading Asian giant hornets, yet another scourge of 2020. Nicknamed “murder hornets,” Vespa mandarinia is the largest hornet species in the world at terrifying 2 inches long, with a quarter-inch stinger that can puncture beekeepers’ suits. Asian giant hornets can quickly destroy an entire hive of bees by decapitating them.

The hornet’s native range extends from northern India to east Asia. They were discovered in British Columbia last fall. The Washington State Department of Agriculture collected two dead Asian giant hornets in Blaine in December. Scientists later determined the hornets in Canada originated in Japan, while the ones found in Washington originated in South Korea. The theory is the hornets traveled to North America after becoming trapped in shipping containers from their native countries.

In fact, the hornet is one of numerous invasive species capable of spreading more easily due to the frequency and speed of modern transport. The Asian gypsy moth, which has the potential to devastate Pacific Northwest forests, is a prime example. The state agriculture department has waged a decades-long, so-far-successful campaign to prevent the moths from establishing here.

Most non-native species fail to gain a toehold, but the ones that do can run rampant in the absence of natural predators that keep them in check in their usual habitat. And most don’t make headlines like the so-called murder hornets. The state Department of Agriculture, by the way, is “not a fan” of the nickname, Salp said.

“The human health impact has definitely been overblown in the media,” she said. “Our research indicates there’s about 10 to 20 deaths due to all stinging insects in Japan each year.”

Unless you have an allergy or are stung multiple times, Asian giant hornets aren’t likely to kill you, she said, although “it’s one of the most painful stings in the world, definitely.”

Asian giant hornets making themselves at home here would endanger bees and wasps, pollinators that are important to agriculture and the ecosystem, Salp said. The hornets also gobble tree fruit and berries.

“The environment is pretty much perfect in Western Washington and Oregon for Asian giant hornets,” Salp said. “Whether they can actually establish here remains to be seen. Our No. 1 priority is to try to prevent that from happening.”

On Friday, the Washington State Department of Agriculture announced that for the first time, it had caught an Asian giant hornet in one of the 467 traps it set in early July, when hornets become active. The hornet came from the contents of a bottle trap near Birch Bay collected July 14. The department’s entomology lab identified the hornet while processing specimens on July 29.

The agriculture department will use infrared cameras to search for nests, as well as attempt to catch live Asian giant hornets to tag and track them back to their colony. The department hopes to find and destroy the nest by mid-September before the colony can create new reproducing queens and drones.

Cooperating agencies, nonprofits and citizen scientists have placed 1,377 traps in addition to the state’s. The agriculture department is not recruiting anyone outside Whatcom, Skagit, Island, San Juan, Jefferson and Clallam counties to place traps, although some in Southwest Washington have, and more are welcome to do so, Salp said.

It’s a big commitment, she warned. No commercial traps are available, so you have to build your own out of plastic bottles and fill them with orange juice. Then you must submit reports along with any bees, hornets or wasps you catch each week through fall.

Asian giant hornet workers become more numerous in August and September.

If you think you’ve spotted an Asian giant hornet, you can file a report with the state Department of Agriculture on its website at or by calling 1-800-443-6684. It’s best if you include a close-up photo, along with the exact location, Salp said. If you find a dead specimen, send that in, but don’t kill any insects, she said.

“We don’t encourage people, especially in your area, to kill something because 99.9 percent of the time it’s not an Asian giant hornet,” Salp said. “We don’t want people killing bees and wasps that play a beneficial role in the environment.”