The eradication of the first nest of Asian giant hornets on US soil somewhat resembled a science fiction depiction of an alien landing site. A crew of government specialists in white, astronaut-like protective suits descended upon the hornet nexus to vanquish it with a futuristic-looking vacuum cleaner, to the relief of onlookers.
The nest of the fearsome invasive insects, notoriously known as “murder hornets”, was found in a tree crevice near Blaine, in Washington state, via a tracking device attached to a previously captured worker hornet. The Washington state department of agriculture (WSDA) confirmed the nest had been successfully removed, with dozens of live captives taken back for inspection.
“It was cold so they were docile, so between their slowness and the protective gear no one was hurt,” said Chris Looney, a WSDA entomologist who was tasked with vacuuming up the hornets.
Wielding a lengthy, toxic stinger, the hornets can cause renal failure and death in people, as dozens of people in Japan have found out to their cost. One entomologist in Canada described the feeling of being stung as like “having hot tacks pushed into my flesh”.
Watch: What it takes to dismantle a 'murder hornet' nest
They can also squirt venom, as Looney saw first-hand when his lab workbench was sprayed by hornets as they roused themselves following capture. “I was more worried about getting permanent nerve damage in the eye from the squirted venom than being stung,” said Looney, who wore goggles for the capture. “They are pretty intimidating, even for an inch-and-a-half insect. They are big and loud and I know it would hurt very badly if I get stung. They give me the willies.”
Murder hornets do not earn their moniker from killing people, however, with honeybees far more likely to be targeted. A honeybee colony can be decimated within a few hours, with the hornets decapitating their victims and feeding severed body parts to their young. This poses a gnawing concern for hobbyist beekeepers and even farmers in the US north-west, where managed honeybees are crucial for the pollination of crops such as blueberries and raspberries.
Asian giant hornets were first discovered in North America last year, popping up in British Columbia, Canada, before a handful of specimens made it south of the border to Washington state. The hornets, native to east Asia, most likely arrived on the continent clinging to imported goods sent via sea or air. A close relative of the hornet has already made separate inroads into France and the UK.
A key, and unnerving, question is how far they will manage to spread across America. Looney said the removal of the first nest found in the US was just a “small victory” in a battle likely to rage for several years to contain the insects. Thousands of sightings have been reported in Washington, and while many are false or mistaken, Looney said it was likely the hornets had spread, potentially establishing dozens more nests.
“It’s hard to say how they will behave here compared to their native range, but the fear is that there are large apiaries of bees that could be sitting ducks, while as the hornets move south to warmer weather their colonies could grow larger,” he said. “The object of our work is to avoid finding this out.”
Scientists who have modeled the potential spread of the hornets predict they will be able to extend down the west coast into California. The Rocky Mountains and drier interior of the US pose major barriers to an eastward push but environs on the east coast such as New York would be ideal homes for the murder hornets should they inadvertently be transported there.
Watch: Wildlife officials isolate two murder hornets
Looney said he was “troubled” by evidence that overwintering hornet queens like to bury themselves in straw and hay, commodities that are regularly shifted around the US by train or truck. A hornet queen that hitched a ride would still face challenges establishing a nest even if moved to the east coast – it could immediately be crushed underfoot, after all – but the potential pathway is there.
“I’m more worried about human transportation of these hornets than I initially was,” Looney conceded.
The Asian giant hornet is just the latest invasive species to make its mark on North America. Burmese pythons are now legion in southern Florida, while Asian carp are common in the Mississippi river system. In the insect world, the spotted lanternfly is a growing agricultural pest and emerald ash borers have arrived to lay waste to stands of trees.
These arrivals are symptoms of the growth in international trade and tourism, while climate change is making many parts of the US more hospitable for certain invasive species. The Asian giant hornet, for example, is thought to favor the sort of elevated temperatures that the US is experiencing as the planet heats up. This could help it spread at the rate of its cousin species in France, which has been able to advance up to 78km a year. If it is not controlled, the murder hornet could fundamentally change ecosystems across the US.
Still, even in a fraught year racked by a pandemic, social unrest and economic disaster, Looney said any fears of being assailed by a murder hornet should be “low on the anxiety meter”.
He added: “We should be concerned about it but we will do our best until the money runs out or the battle is won or lost. If we fail, it will be unpleasant. But there are other things to be much more worried about right now.”