We don’t have to fear murder hornets
Maybe because anxiety over the COVID-19 pandemic has jangled our nerves, reports of an enormous hornet native to Asia that resembles “something out of a monster cartoon,” decapitates honey bees, administers an excruciatingly painful and occasionally fatal sting and has been spotted on North America’s West Coast are making us particularly jumpy.
An incendiary headline — ‘Murder Hornets’ in the U.S.: The Rush to Stop the Asian Giant Hornet — this month in The New York Times was alarming, as was reporting that used words like “ferocious,” “lethal” and “carnage” to describe its behaviour.
Should we be worried that the Asian giant hornet — scientific name Vespa mandarinia — could be en route to Quebec?
No. We should have “absolutely no concerns” about that, said Morgan Jackson, a postdoctoral fellow in biology at Mcgill University.
The hornet, which can reach five centimetres in length with a seven-centimetre wingspan, was initially sighted in December in Washington state, not far from the British Columbia border.
“It looks like something out of a monster cartoon, with this huge yellow-orange face,” Susan Cobey, a bee breeder with Washington State University’s entomology department, observed in a university publication.
A nest on Vancouver Island was located and destroyed last summer; in November another specimen was found less than 10 kilometres from the Washington border. British Columbia’s agriculture ministry has warned residents near the border to report any sightings this spring and summer.
The goal is to keep the hornets from becoming established in their communities, said Jackson, although even if they did, “it would take them years and years to spread across the country.”
A close relative, the European hornet (Vespa crabro), was introduced to New York state in the 1800s — and took more than a century to get to Arkansas, about 2,000 kilometres away, he said.
“There is no sign of this species on the East Coast so far,” said André-philippe Drapeau Picard, a biologist specializing in entomology and an information officer with the Insectarium de Montréal.
“We don’t think it will come here — at least not in the near future.
“The West Coast is quite far away and there are the Rockies between there and here — a huge barrier to dispersal.”
As well, the Asian giant hornet is subtropical and “our severe winters are a huge ecological filter for many introduced species,” said Drapeau Picard.
The hornets probably arrived in shipping containers from Asia, said Emma Despland, a professor in Concordia University’s biology department who studies plant-insect interactions.
They’re not likely to “spread across Canada any time soon,” she said. “But the species could spread gradually over the years, if eradication is not successful.”
Concern about the hornets establishing a permanent presence in British Columbia is twofold, Despland said: they are serious predators of the honeybee, the world’s most important pollinator of food crops, and, indirectly, a risk to human health.
Asian giant hornets aren’t particularly aggressive unless they’re threatened or their nests, which are in the ground, are disturbed. Still, swarms do kill dozens of people in Asia every year.
But to call them murder hornets is “kind of a misnomer,” Despland said. “They’re just hornets who eat bees. They are not more murderous than other giant hornets.”
Asian giant hornets are most destructive in late summer and early fall, as they hunt for protein sources to nourish next year’s queens. A few dozen can slaughter a hive of 30,000 honeybees within hours.
The Asian giant hornet resembles the less aggressive European hornet, Despland said. “If you see a large hornet in Montreal, it’s much more likely the European species.”