Researchers race to find Asian giant hornet nests before "slaughter phase"

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Threat of the Asian giant hornet establishing itself in Blaine before spreading across the state, and potentially the West Coast, looms as the hornets enter the ‘slaughter’ phase of their life cycle in early fall. 

On September 30, the Washington State Department of Agriculture got one step closer to meeting its goal of finding at least one of the underground nests, thanks to a few leads from residents in east Blaine, near Burk Road. 

A week earlier on September 21, Philip Bovenkamp was working outside when he heard a low-pitched hum, similar to a hummingbird but different from anything he’d ever heard. Bovenkamp followed the noise, suspicious after his wife had doubted a sighting earlier that week and he had seen something large fly by earlier. He’d been on high alert for bugs because his fifth-grade daughter, Jillian, was catching them for an entomology project at her school in Lynden.

Bovenkamp, who lives on 5 acres, traced the unfamiliar noise to a hornet inspecting a paper wasp nest in his tool shed. After one Google search, he was able to verify the large orange-and-black hornet with almond-shaped eyes was the same invasive insect scientists were calling on the public to trap.

As October neared, researchers needed people to spot the hornets more than ever as the insects enter their slaughter phase, when they attack their prey in force for food. With nests established and new queens preparing to mate later this month, scientists said, time to prevent honeybee killings runs short. 

If not controlled in Washington state, the hornets could spread down the West Coast and eventually reach the East Coast and even the coasts of Africa, Australia, Europe and South America, according to a Washington State University study published September 22. The hornet thrives in areas with warm summers, mild winters and high rainfall, which means eastern Washington and the U.S. interior are inhospitable to the invasive species, the study found. 

After confirming the pest’s identity, Bovenkamp returned and emptied a can of wasp spray before scooping the dead hornet into a container. “I thought that would be the end of my murder hornet adventures,” he said.

But that evening, Bovenkamp saw another one pestering a paper wasp nest above their grill. 

His wife, Debbie, made two traps from the WSDA website and caught a hornet the next day. “At that point, we were thinking if we’re seeing this many in this short of time, we thought we might not be the only ones,” he said. 

Debbie Bovenkamp reported the sighting to WSDA that Saturday, September 26, thinking they’d just be “pins on a map.” But by 1 p.m. Monday, WSDA entomologist Chris Looney pulled into the couple’s country property and told them it was the best lead the agency had. 

It wasn’t until Looney was preparing to leave the property on Tuesday, September 29 that he and Bovenkamp saw a hornet buzz by. Looney caught the live hornet in a butterfly net and by the next morning, seven WSDA representatives were at Bovenkamp’s home preparing to track the hornet back to its nest – a culmination of months of effort.

The scientists placed the hornet in ice to slow its metabolism long enough to attach a radio tag that could follow the hornet back to its nest, suspected to be within 2 miles of Bovenkamp’s property. The tag, tracked via a cellphone app, worked properly but the glue didn’t dry fast enough, sticking to the hornet’s wing and making it unable to fly, said Sven Spichiger, WSDA entomologist during an October 2 news conference.

The entomologists then attempted to tie the tag to the hornet with thread, similar to how European scientists track the Asian hornet, a different invasive species. 

“We absolutely believe we are going to get more live hornets,” said Spichiger, of the hornets believed to be workers. “We are supremely confident that in the next couple of weeks, we’ll be able to snag one, if not more, of them.”

The WSDA response team added 30 live traps to the Bovenkamp’s neighborhood, an area previously outside its concentrated trapping grid. While knocking on neighbors’ doors for permission to hang the bottle traps, agency staff found a dead hornet in a street lamp. They were also given a doorbell camera photo of a hornet and heard a third report of the hornet found dead on a porch, which the resident discarded. 

“We have basically six specimens in the last week,” Spichiger said. “We, of course, believe we are dealing with a nest and we will be watching that particular area pretty close.”

For months, researchers had looked for any sign of even one hornet. Seeing one after another appear in east Blaine became a victory of sorts.

“There were a lot of emotions for our staff this week,” said Karla Salp, WSDA public engagement specialist. “We feel very close because we have all these detections in this little pocket.”

These sightings bring the total count to 15 confirmed Asian giant hornets trapped in Washington, all of which have been found in Whatcom County, Salp said. 

Since the most recent sightings were less than two miles from the U.S./Canada border, B.C. officials have added six more traps just north of the border. There hasn’t been a confirmed hornet sighting in B.C. since one was found in Langley in May. 

Paul van Westendorp, provincial apiculturist for B.C., said he doesn’t have an exact number on traps in B.C. but they are surveying three areas: Nanaimo on Vancouver Island, where a nest was eradicated last September; the Cowichan Valley, south of Nanaimo, where there were four credible sightings in June; and the Fraser Valley from White Rock to Aldergrove. 

“These hornets are not respectful of any border,” Van Westendorp said. “They just fly wherever they’d like to go.” 

DNA sequencing tested last winter suggests the hornet found in Blaine in December and the Nanaimo nest had separate origins, South Korea and Japan, respectively, Van Westendorp said. A different large hornet species from Asia, he said, was also found in Vancouver in the summer of 2019. This hints that the Asian giant hornets could have been introduced at separate times, although van Westendorp noted the DNA sample is not a foolproof indicator because the hornets can move from the area where they are predominantly located.  

“The question can be raised, do we do enough to control and check for invasive species that could have huge implications to our forests?” he said.

Spichiger said the recent sightings confirmed the hornets prey on yellow jackets, paper wasps and other native pollinators besides the honeybee, which could have a greater impact on the environment. The gravity of wide-scale impact is currently hard to determine, Salp added. 

Residents have spotted the hornets checking for wasp nests under building structures such as carports and the edge of roofs, said Salp, who recommends people keep a special eye on those places.  

Because all of the 15 Asian giant hornets trapped in Washington have been found in Whatcom County, local beekeepers dread the coming slaughter phase. 

Although there have been no beehives attacked this year, Ted and Dorothy McFall are still reeling from discovering an entire colony slaughtered last November. The hobbyist beekeepers of McFall Beeyard in Custer found thousands of decapitated bees from one of their 30 colonies, a few weeks before the first hornet was found in Blaine.

“It’s pretty unfortunate we happen to live in the one part of the United States where they are, and to have the bait,” said Ted McFall, who has been beekeeping his entire life. 

McFall said it’s hard to estimate how much revenue they lost from losing their strongest colony because they could have made many uses from the colony over the years, including breeding queens and pollinating farmers’ crops. He worries their bees could get hit again this year, but worse, if there are two hornet nests in the area, which WSDA officials say is likely after the Birch Bay sightings this summer. Officials also haven’t ruled out a third nest in Custer after a male hornet was trapped in late July. 

The McFalls said they wouldn’t have a ‘fighting chance’ without the support of the community, most of whom won’t be affected directly. 

“It’s comforting. I’m glad we’re not alone in this fight,” Dorothy McFall said. “It’s like the beginning of a forest fire. You try to put it out early before it gets too late.”

WSDA created an emergency line for Whatcom County beekeepers who experience hives under attack, similar to 911. WSDA officials emphasized that beekeepers calling the 360/902-1880 number must note the direction the hornets fly, and any other detail that could help tracking efforts.

In the days following his hornet escapade, Bovenkamp said he’s taking extra walks around his yard and chatting with neighbors about the latest topic there. His daughter, Jillian, is now one of two people in North America with an Asian giant hornet, which WSDA allowed her to keep for her school project. She keeps her school project in their outdoor freezer, next to the white chocolate raspberry ice cream and frozen berries. 

“The department of agriculture is going above and beyond. They’re up here all week trying to track those things down, but they need our help,” Bovenkamp said. “Every report we get helps them zero in a little bit closer.”

Walking through his backyard to point out where the hornets were spotted, Bovenkamp cocked his head and paused. “I thought I just saw one, a hornet,” he said. “It buzzed around the top and just took off. It’s the first time I’ve seen one since Saturday morning but I’m fairly confident that was one.”

To report an Asian giant hornet sighting, visit bit.ly/34akL4H. People without internet can also call the hotline, 1-800/443-6684 but this will take longer for WSDA staff to respond due to a heavy call volume. Beekeepers with hives under attack are urged to call the emergency line, 360/902-1880. For more information, visit agr.wa.gov/hornets. 

 

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