Good news! The invasive insect formerly known as the “killer hornet” could soon come under control in Washington state. After wrapping up the 2022 pest trap season, the Washington State Department of Agriculture (WSDA) reported no sightings of the northern giant hornet.
“When it comes to the pests we research, the best news is no news,” said Sven Spichiger, WSDA entomologist, in a press release yesterday.
It is still too early to declare complete victory over the hornet. It takes three years with no sightings before the pest is considered “eradicated” under federal guidelines. But this is the first year without sightings since the first report of a northern giant hornet in Washington in 2019 set alarm bells ringing.
“The best news is no news”
Washington officials feared the hornets, native to Asia, would decimate honeybee hives if they gained a foothold in the state. Just a few hornets can destroy an entire hive in hours, according to the WSDA. In the “slaughter phase”, the giant hornets go on decapitation. Eventually, the hornets take the hive as their own and use the decapitated dead to feed their own young. So you can see how the little critter got the nickname ‘murder hornet’.
Bees in Japan have learned how to defend themselves against the invaders by using their numbers to defeat the larger hornets. The bees will swarm around an individual hornet, overheating and suffocating the hornet to death. But North American bees have not yet learned to wage war against the invasive species.
To see some of this in action, there is a documentary called Nest Zero you can watch. It’s a nail biter; Washington’s Public Affairs Network, TVW, won an Emmy for it last year.
All the publicity helped mobilize the state against the invading hornets. Because if there are murderous hornets out there, your friendly neighborhood entomologists might need a little help. Washington state residents reported the first sightings of northern giant hornets in 2019, 2020 and 2021.
For the record, “murderous” applies especially to bees. It is not common for the northern giant hornet to go after people or pets. Scientists argued that the nickname “killer hornet” was inaccurate, as the bees are not aggressive towards humans. For a time, the hornets went by the common name “Asian Giant Hornet.” But the Entomological Society of America changed that to the northern giant hornet this year after concerns it could fuel anti-Asian sentiment.
However, “Giant” is quite accurate for the hornet’s impressive physique. This species of hornet is the largest in the world and can grow up to two inches long, which thankfully makes them easier to spot. They have stingers long enough to pierce a beekeeping suit and can sting repeatedly. Their venom is also more poisonous than that of bees.
This year, the state launched an “adopt a wasp” program to enlist the help of citizen scientists in finding the invasive species. Some northern giant hornets had been seen attacking paper wasp nests in Washington, so the WSDA asked residents to “adopt” a paper wasp nest, promising to visit and observe it at least once a week and to report any signs of giant hornets to report.
WSDA entomologists were first able to locate and destroy a northern giant hornet nest in October 2020. They used dental floss to tie a radio tag to a hornet and track it home. Destroying the nest involved sealing off entrances, wrapping the nest and the tree it was in with cellophane, then inserting a vacuum hose to suck up the hornets. Then they pumped CO2 into the tree to kill any hornets still hiding in the tree.
On the road to 2023, entomologists remain vigilant. The WSDA is still asking the public to look out for the northern giant hornet and report any sightings. They have an online Hornet Watch Report Form and residents can email email@example.com or call 1-800-443-6684.
“While there is promise in not detecting hornets this year, the work to ensure they are eradicated is not over,” Spichiger said.