Hunt for the Asian Giant Hornet Turns Up Another in Washington

Posted

An Asian giant hornet has been found in a Washington State Department of Agriculture trap near Birch Bay, the agency announced on Friday, July 31.

It was found in an area just north of the BP Cherry Point Refinery and about 6 miles from the first reported hornet in the Blaine area in early December, Sven Spichiger, managing entomologist for the department, said during a virtual press conference on Friday.

The hornet was nearly 2 inches long.

The agency and volunteer citizen scientists began trapping for the invasive pests, also widely known as "murder hornets," in spring -- after they were first spotted in Whatcom County, and by extension the state and the U.S., in 2019.

"This is encouraging because it means we know that the traps work," Spichiger said in a Friday news release. "But it also means we have work to do."

The bottle traps had been considered experimental because no one in the U.S. had trapped for Asian giant hornets previously, although the traps have worked in Japan and Korea.

Breaking news & more

Sign up for one of our many newsletters to be the first to know when big news breaks

SIGN UP

"You never really know if a trap is going to be effective in a new area because of competition from other things that they just don't have in Japan and Korea," Spichiger explained.

The state agency's trappers checked a bottle trap near Birch Bay on July 14 and sent what they found to its entomology lab in Washington, D.C. The hornet was identified during processing on July 29, and work is continuing to determine whether it's a queen or a worker.

This was the first hornet to be found in a trap.

The previous five confirmed sightings, all in Whatcom County, were found by county residents outside of traps.

This makes six confirmed sightings in Whatcom County, and Washington state, since 2019. Before this specimen, three were reported in and around Blaine, one in Custer and one in Bellingham.

Since the first reported sighting in the Blaine area in December, other specimens that were found earlier were sent in to state agriculture officials.

The burly hornets are known for their painful stings when threatened and feared for the threat they pose to honeybees -- they can decimate hives quickly -- and, by extension, the hundreds of crops in Washington state that the bees pollinate.

The goal is to find the hornets and their colonies and destroy them to prevent the pests from reproducing and spreading in the Pacific Northwest.

Next steps

While it still hasn't been determined whether the trapped hornet was a queen or a worker -- it's size falls somewhere in between -- Spichiger said officials are proceeding as if it is a worker from a nest that must be found.

The typical flight range for a foraging Asian giant hornet is within 1-1/4 miles from a nest, although it could be as much as 5 miles, he said, adding that the one that was trapped was likely on the low end of that distance.

Agriculture officials said they will next search for the nest using infrared cameras as well as put up more, different traps to catch Asian giant hornets but keep them alive.

If live ones are trapped, the department will try to tag them in order to track them back to their colony and then kill them.

Workers have practiced by putting fake trackers on native bald-faced hornets, according to Spichiger.

The ones for the Asian giant hornets will use radio frequency and that could present a challenge because the hornets that have been discovered in Whatcom County usually nest in the ground, meaning the signal could be lost at some point.

Regardless, they should be able to at last get vector lines back to the nest, he explained.



Officials hope to find and destroy the nest by mid-September. That's before a colony would start creating new queens and drones that could reproduce.

Until then, the colony will contain only the queen and worker Asian giant hornets, and destroying a nest before new queens emerge and mate will prevent the hornets' spread, officials explained.

If a nest is found, the state will go in at night to destroy it.

That's when most hornets will be back in their nest, Spichiger said, adding that will allow workers to turn on red lamps to see what they're doing without allowing the hornets to see.

It makes it a little bit safer, Spichiger said, and gives workers an advantage that the hornets don't have.

The state has had to order special suits because the ones used by beekeepers are too thin to protect against the hornets' sting.

About the size of an adult thumb, the Asian giant hornet, or Vespa mandarinia, is the world's largest hornet and a predator of honeybees and other insects. They are identifiable by their large yellow/orange heads.

The invasive hornets' native range is Asia. They also are known as the Japanese hornet, yak-killer hornet, the giant sparrow bee and popularly as murder hornets after a New York Times article.

Asian giant hornets are typically dormant during winter. They're seen usually from July through October, though most likely in August and September as the number of workers increase as a colony grows.

They primarily nest in large colonies in the ground -- in hollows formed by rotting roots, hollow trunks and rodent burrows. They can, though rarely, nest above ground in hollow trees and human structures, state agriculture officials have said.

Report it

If you think you've seen an Asian giant hornet, the Washington State Department of Agriculture wants you to report it.

Provide as much detail as you can about what you saw and where. Get a photo, if you can safely, and submit it. If you find a dead Asian giant hornet, keep it for potential testing.

Here's how to report it:

-- Go online to the Hornet Watch Report Form.

-- Email PestProgram@agr.wa.gov.

-- Call 800-443-6684.

-- Stay updated at the Asian giant hornet watch Facebook group.

Learn more at agr.wa.gov/hornets, including how members of the public can create bottle traps for Asian giant hornets.

More than 1,800 traps -- mostly across Northwest Washington -- have been set by the department, other organizations and citizen scientists.

Those interested in trapping still have time to build and set traps on their own property, officials said.

___

(c)2020 The Bellingham Herald (Bellingham, Wash.)

Visit The Bellingham Herald (Bellingham, Wash.) at www.bellinghamherald.com

Distributed by Tribune Content Agency, LLC.