Asian Giant Hornet

A fourth Asian Giant Hornet nest eradication is planned for Thursday, Sept. 23. The nest is located in north Whatcom County. (Courtesy photo)

WSDA to eradicate fourth nest; potential Nooksack sighting still under investigation

WHATCOM — The Washington State Department of Agriculture has eradicated three Asian Giant Hornet nests since late 2020 and has its eyes on a fourth nest later this week.

All located in north Whatcom County near Blaine, these nests are dangerous because the hornets that live in them are invasive and known to kill adult honeybees and take their larvae and pupae back to their own nests to feed their broods.

The fourth nest was discovered a couple of weeks ago, but its location makes it difficult to eradicate. It’s about 20 feet off the ground, said Karla Salp, public engagement specialist with the Washington State Department of Agriculture. Special equipment will be required to eradicate the nest.

Salp said all four nests were initially located using tracking technology. According to the United States Department of Agriculture, these radio tags, most recently used to track the invasive spotted lanternfly on the East Coast, are attached to captured hornets, which are then followed to their nests. A typical eradication consists of USDA entomologists plugging a nest with foam, wrapping the tree in plastic and vacuuming out the hornets. The team also injects carbon dioxide into the nests to catch any stragglers.

When the WSDA eradicated the second Whatcom nest in late August in a rotten alder tree, it discovered almost 1,500 hornets inside, including a queen, 292 eggs, 422 larvae and 563 cap cells (developing hornets), along with 195 workers, WSDA Managing Entomologist Sven Spichiger said in a recent press conference.

  he hornets in that nest behaved a bit differently than the ones in the 2020 nest, he said.

“This nest was a little more aggressive than the nest we encountered in 2020,” Spichiger said. “There could be a number of reasons for this, but in general, they were more interested in what we were doing, whereas the nest in 2020, they barely paid us any mind.”

Salp said the fourth eradication is planned for Thursday if all goes according to plan, and it’s a crucial time for tracking these creatures.

“I think just that we’re getting close to the time of year when Asian Giant Hornets will start producing the reproductives, so the males and the new queens, so this is a really critical time for people to take photos and submit suspected sightings to us,” Salp said.

Anyone who sees an Asian Giant Hornet can report it at agr.wa.gov/hornets. While the first four nests located in Whatcom County have been within just a few miles of each other near Blaine, Salp said WSDA is currently tracking a potential sighting near in the Nooksack foothills. It’s unclear if the photographed insect is actually an Asian Giant Hornet, she said.

“We had a suspicious report that included a photo that was out by the Nooksack area headed into the mountains,” Salp said. “We can’t confirm it. We also can’t rule it out based on the photo that was sent. In that area in particular, we’re asking people to keep an eye out and send photos if they think they’ve seen one.”

WSDA has traps set around the county, including ones tended to by citizen scientists, but photos and sightings are just as effective as these traps, Salp said.

Salp said there’s really no way to know how far the Asian Giant Hornets have spread.

“It’s just anybody’s guess, really,” she said. “We know we got that one nest last year and it looks like these are related to that nest. We are testing to make sure. We haven’t detected any in any other areas that are confirmed.”