Wasp sightings revive murder-hornet concerns

You only saw it for an instant before it got you.

Narrow, translucent wings, patches of loud yellow and obsidian black; sharp, alien features and an even sharper stinger. Good heavens, the size of it!

At first glance, it may seem this could only mean one thing — that five years on from their first Canadian sighting in 2019, they may have finally come to your neighbourhood. The dreaded northern giant hornet, better known as the “murder” hornet, is here, right?

Or was it just a regular wasp?

As temperatures rise out of a mild El Nino winter, Canada’s buggy season is already upon us again, and with apocalyptic visions of supposed killer insects still fresh in the minds of gardeners, beekeepers and afternoon-stroll enthusiasts alike, it’s easy to let your imagination run away with you.

Frightening though it may be, the prospect of buzzing death sweeping across the country remains remote, according to experts. More likely than not, the little monsters stalking your garden and harassing your local apiarist are one of many native or naturalized species, not a new or invasive bug.

“What we see in any given year is going to change — right place, right time,” said University of Toronto entomologist Rosalind Murray, in an interview with CTVNews.ca. “With climate change … it’s warmer, but the daylight hasn’t shifted; [that] can make animals a little bit confused … it could be that some people are seeing, for the first time, these very confused hornets.”

Here’s how to tell if the angry creature sticking out of your arm is worth raising the alarm for:

Them!

Formerly known as the Asian giant hornet, the northern giant hornet is a species of wasp native to India, China, Korea and Japan. The largest known species of hornet, they can grow to five centimetres in length, according to the Invasive Species Centre (ISC), a Sault Ste. Marie, Ont., nonprofit.

The hornets’ homicidal nickname can be traced to their highly predatory behaviour toward North American honeybees, not humans — in fact, the ISC points out, though their sting is known to be painful, they typically only act aggressively toward larger animals if their nest is threatened.

Northern giant hornets grabbed headlines in 2019 when officials in Nanaimo, B.C. and Washington state spotted specimens on both sides of the border. To local insects and arthropods, they pose serious risk to life and limb, which can also hurt plant populations as key pollinators come under attack.

In the years since their west-coast discovery, governments have maintained a policy to destroy the invasive hornets’ nests wherever they are discovered, and residents are encouraged to report sightings to their provincial conservation authorities.

With temperatures creeping upward across North America, concerns have historically been raised about the widening area where a species like the northern giant hornet could conceivably survive the winter, hypothetically allowing for geographic spread.

Sven Spichiger, Washington State Department of Agriculture managing entomologist, walks with a canister of Asian giant hornets vacuumed from a nest in a tree behind him Saturday, Oct. 24, 2020, in Blaine, Wash. (AP Photo/Elaine Thompson)Luckily, confirmed sightings have been sporadic. A cross-border database maintained by the Washington State Department of Agriculture (WSDA) shows that though northern giant hornets have been detected on 45 occasions since it began tracking them, the most recent of which was in 2021.

“The work to ensure they are eradicated is not over yet,” said WSDA managing entomologist Sven Spichiger in a November 2022 release marking the first season without a sighting since 2018.

For WSDA to declare the species eradicated, three consecutive seasons must pass without detecting a nest or specimen. Canada, meanwhile, prefers to wait five years. With those milestones drawing closer this year, it’s helpful to know just what they’re looking for — and what they aren’t.

If it flies like a hornet…

This spring, social media posts of large, hornet-like bugs have cropped up thousands of kilometres from the B.C.-Washington border, in eastern Ontario.

“Found this beast on our deck!” reads a post on a Carleton Place, Ont. Facebook group, depicting a large, yellow-black insect nearly half the length of the photographer’s thumb.

“In recent days I have seen this huge, what looks to be a large wasp, around my home,” reads another post. “It was amazing to see the size of this thing. I guess about [two] inches [five centimetres]! HUGE!”

A cursory search of local community groups returns plenty of frightening specimens hanging from branches, butting against the inside of homemade traps or brazenly taking flight, but alongside them are a cadre of amateur entomologists reminding locals not to jump to conclusions.

“I’ve been seeing a flurry of post[s] on local groups worrying that they’ve seen an Asian Hornet AKA the Murder Hornet or Northern Giant Hornet (which has never been seen in Ontario), when in fact it’s actually a European Hornet (non invasive),” wrote a Smiths Falls, Ont. group member in a self-described public service announcement.

They’re not the only ones to note the similarity. The ISC describes European hornets, which have resided in Canada as far back as the mid-1800s, as the species most commonly mistaken for the northern giant hornet, typically measuring a little over half the size, with lighter yellow colouring and distinctive, keyhole-shaped markings on each of their black stripes.

European hornets do not pose the same threat to the local environment, and are considered “naturalized” to Ontario’s ecosystem, according to the centre. Other species that could be confused with the so-called murder bugs: The bald-faced hornet, the yellowjacket wasp and the similarly named eastern cicada killer; all of which native or unobtrusive to eastern Canada, in modern times.

A size comparison of the Asian giant hornet and several other insects. (Washington State Department of Agriculture)“Fortunately, there is currently no evidence of the northern giant hornet in Ontario,” an article on the ISC website reads.

“This means that we must continue to be vigilant and work to prevent their introduction and establishment.”

U of T’s Murray notes that the cluster of hornet sightings of any kind might have a simple explanation: With excellent weather across the region on the first long weekend of the summer, it’s possible that people were outside more than usual.

“They’re just lucky enough to get to seem them, this time,” she said. “Humans behave differently when it’s nice out as well.”

For more information, or if you believe you may have spotted a northern giant hornet, you can seek out your local conservation authority here.