The giant Asian hornets – better known as the murderous hornets – have inspired menacing headlines throughout the summer amid warnings that invading insects could decimate American bee populations. Last month, after various sightings in the Pacific Northwest, officials in Washington state discovered and removed the first known deadly hornet nest in the United States.
As authorities continue to search for more nests to destroy in hopes of eradicating the hornets from the country, entomologists are revealing what they have learned from the nest’s first removal.
“It really looks like we got there on time,” Sven-Erik Spichiger, senior entomologist in the Washington State Department of Agriculture, said at a news conference on the nest’s findings this week.
Here’s what the scientists found.
The nest could have held around 200 queens.
At the end of last month, authorities in Blaine, Washington, removed the nest of aggressive hornets – which were about to enter their “slaughter phase” – before they could multiply and kill them. domestic bees from the area. If they had not been removed, the insects could have devastated pollinators essential to raspberries, blueberries and other crops in the region.
The hornet is not native to the United States and can be more commonly found in Asia, where it is known to kill up to 50 people per year in Japan.
Blaine’s settlement was located in an area of forest and farmland after authorities attached radio trackers to three hornets they had trapped earlier. One of these hornets led the officials to the nest, which was about eight feet in a tree.
Entomologists extracted a few hundred hornets with a vacuum, then sealed the rest of the nest on Oct. 24, Spichiger said at the press conference, which was held virtually Tuesday. Authorities then removed the section of the tree where the nest had been sealed and took her to a quarantined research facility at Washington State University.
On October 29, authorities opened the nest to find most of the insects still alive. Including the hornets that were sucked in a few days earlier, officials said they removed around 500 hornets at various stages of the life of the nest, which measured around 14 inches long and at least eight inches wide.
In addition to the 112 worker hornets found, there were hundreds of larvae and pupae (the stage of life after larvae), as well as eggs and male hornets. Mr Spichiger also said the nest is capable of holding around 200 queens.
The nest is smaller than those found in areas where hornets are native, where there may be up to 700 queens, Mr Spichiger said.
Some queens were able to escape.
Although Mr Spichiger said authorities removed many queens from the nest just in time, he said some may have escaped and formed new colonies next year.
At least three queens were found in a bucket of water nearby after extraction, he said, adding that it was impossible for officials to ensure they caught all of the hornets or how many there might be.
“When you see all the relatively small nests capable of popping 200 queens, it gives a bit of a break, because eventually each of those queens could become a new nest,” he says.
If queens did escape, they might not survive if they had not received adequate nutrition before leaving the nest. But if a person was properly fed and mated with a male, they could theoretically leave and choose a protected area to isolate during the winter, helping to form new colonies in the spring.
“It’s clear since we captured specimens last year and captured queens early, that a few of them were successful in establishing nests in 2020,” he said.
There might still be nests there.
Hoping to eventually eradicate the hornets, state Department of Agriculture workers will continue to trap them until at least Thanksgiving.
However, officials will not follow queens they might capture as they likely won’t return to a nest for officials to eradicate. At this point in the season, the best chance for officials to locate another nest is for hornets to continue attacking a beehive, Mr Spichiger said.
The finds from this nest have left officials unsure of how the hornets got to the Pacific Northwest. Mr Spichiger said it was likely that a mated queen made it to Washington through international trade. He also said it was possible someone had smuggled the hornets into the United States to breed them for food. (They are sometimes eaten as snacks or used as an ingredient in alcoholic beverages.)
Even if there are no other hornets found in the area in the future, authorities will continue to use traps for at least three more years to ensure the area is free of hornets.
“These are not going to hunt you down and murder you,” Mr Spichiger said. But, “If you walk into a nest, your life is probably in danger.”
Yet, he added, “your life is also in danger if you also enter the nest of other biting insects.”