It’s been a busy week for Washington state agriculture officials tracking the potential spread of the Asian giant hornet. Scientists say they found evidence of six new hornets near Blaine, indicating the likelihood that a nest is in the area.
The invasive species, sometimes called murder hornets, can decimate honeybees and other pollinators, threatening ecosystems and agriculture. Fifteen of them have now been found in Washington since they were first seen here last year.
On Sept. 21, the Department of Agriculture got a report from a private landowner near Blaine, who saw a giant hornet flying around outside and heard unusually loud buzzing in his attic.
"It was apparently repeatedly visiting paper wasp nests on the eaves of their house,” said state entomologist Sven Spichiger.
Earlier this week, one of Spichiger’s colleagues, Chris Looney, went to the area to meet the homeowner. While there, Looney was able to net a live giant Asian hornet from the air, and then attach a radio tag to it — a first for the agency.
But Spichiger says hornets are not quite as hairy as other insects they have successfully tagged in the past, so attaching the device took longer than expected.
"Unfortunately, the glue did not dry fast enough and the tag slid off of it as we were waiting to release the hornet," he said. "And unfortunately, its wings came into contact with the glue, rendering it unable to fly. So, we were not able to release it to follow it back to the nest.”
They placed additional traps around that area and will keep trying to net a live one to tag and track, with the goal of finding and eradicating the nest.
Another new strategy they’re deploying is the use of so-called “sentinel” hives. They’re working with entomologists at Washington State University and have secured six honeybee hives to use as lures. They’re deploying them in key areas near the Canadian border, where most sightings of the invasive species have occurred. British Columbia has found evidence of several hundred since the first discovery there near Nanaimo in August 2019.
They’re also asking beekeepers to be on alert.
“Because Asian giant hornet, this time of year, starts going into what we call ‘the slaughter phase,’ where they will visit apiaries, basically mark a hive and attack it in force,” Spichiger said.
It’s a brutal scene.
“Removing every bee from the hive, decapitating them, killing all of the workers, and then spending the next few days harvesting the brood and the pupae out of the hive as a food source,” he said.
They’re using the hives as lures, but simultaneously testing an exclusion device to protect the bees. Spichiger says it has been used successfully in Japan to trap the hornets and will be evaluated by the WSU team.
The state also has set up a new hotline where beekeepers can report any attacks and get a 911-style response. With the slogan “track it, don’t whack it,” officials say the most important thing right now is not to kill the hornets, but to follow their flight patterns to find their nests so they can be eradicated.
He says the state is grateful for the cooperation of the public and wants everyone to keep reporting "every single hornet that they see every single time. Especially for the next month." Officials have set up a special webpage dedicated to the effort.
Spichiger noted that the hornets’ predation of the paper wasp nests at the tagging site near Blaine is another sign of how destructive the species can be, as it targets all kinds of pollinators.
“They're also attacking our native wasps, hornets, yellow jackets and things like that,” he said. “To see them doing that, that means they're going to have an impact on our ecosystem past managed honeybees as well.“