Washington State Department of Agriculture. All photos supplied by the Department of Agriculture.
The first “murder hornet” nest found in the United States was hiding in a tree about 20 feet from a children’s play set with a sandbox, a slide, and a swing.
The nest, which the Washington State Department of Agriculture destroyed in late October, was in Blaine, Washington, near the B.C. border and housed almost 200 queens capable of starting their own colonies.
The department’s managing entomologist said the family living on the property, in a cleared space adjacent to woodland, was blissfully unaware of the nest until a team showed up in heavy protective gear packing hornet-slaughtering tools.
“I guess the family was very fortunate in that respect, because in their native range they’re known to pretty viciously defend their nest if a large animal or anything gets too close to it,” Sven-Erik Spichiger said.
“We were probably scarier than the hornets; a bunch of government people coming out of the woods with radio tracking devices probably would give anybody pause.”
Asian giant hornets are the world’s largest hornets at about 4.5 cm long, with a wingspan of 7.5 cm and a venomous stinger that has the potential to kill a human in rare circumstances. They prey on other insects, including honey bees, earning the “murder hornet” nickname.
The insects are native to various parts of Asia and have been popping up sporadically since 2019 in Washington and B.C., where they are considered an invasive pest. A nest was previously destroyed last September by beekeepers in Nanaimo, B.C.
Spichiger’s team found the basketball-sized nest by affixing a radio tag to a lone captured hornet on Oct. 22 and following her back home.
While the nests are usually in the ground, the team was surprised to find this one sitting more than 8 feet up in a tree.
“Let’s just say when I was standing next to the nest I was looking down, not up. So I guess we dodged a bullet there because they didn’t come out and attack us,” Spichiger said.
The team sucked nearly 100 worker hornets out of the nest with a vacuum hose, but encountered some unexpected challenges. The tree was partly rotted out, so they stuffed a memory foam pillow inside to close the gap, then plastic-wrapped the trunk to keep the rest of the hornets inside.
Four days later, when they returned to cut the tree down, they found about 200 queens had emerged from cells inside of it. They took a chunk of the tree to Washington State University, where they used CO2 to freeze and collect the remaining insects.
In total, Spichiger and his team found 500 specimens in 277 cells.
To put that in perspective, some nests in the hornets’ native range have up to 4,000 cells, so there was potential for significant growth.
Spichiger said the fact that 200 queens could have gone on to spawn 200 more nests highlights the importance of catching them early and destroying them as soon as possible.
The hornet-killing team has been following up on reports from the public and learning on the job while soaking up advice from its counterparts in Japan.
The bad news, Spichiger said, is he knows there are some nests in Washington and B.C. that have not been found.
The good news, he said, is reports of murder hornets are still uncommon in North America.
“What that tells me is it’s still contained, we’re still pretty early on in the infestation, and if we jump all over them … we actually do stand a chance of winning the overall war, if you will, and not just this one battle,” he said.
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