US and Canada gear up for another Asian ‘murder hornet’ season

Authorities say invasive species can pose risk to animals and insects, including honeybees, and must be eradicated.

Authorities say the Asian giant hornet's sting is much more dangerous than that of bees or wasps, causing 'severe pain, swelling, necrosis and, in rare cases, even death' in some humans [Courtesy Paul van Westendorp]

Montreal, Canada – While its “murder hornet” moniker draws international attention, Paul van Westendorp prefers to compare the Asian giant hornet to a polar bear.

“The polar bear is very fierce and is dangerous in its environment, but the chances that you and I would ever run into one is pretty low,” he told Al Jazeera in a phone interview from the Canadian province of British Columbia. “It is the same with this particular hornet.”

Also like polar bears, Van Westendorp, a provincial apiculturist with the BC government, said the hornets are apex predators that sit atop the food chain.

“They are ground nesters and with ground nesters, as soon as their nest is disturbed, they have a very strong defence mechanism,” van Westendorp said. “They come out very quickly and they want to make sure … that you get a warning and get out of there.”

Now, as this year’s hornet season slowly starts up with the species coming out of hibernation, scientists and other experts in both the United States and Canada are urging people to keep an eye out for the hornets – and alert authorities of any sightings.

Northwest US and BC

The Asian giant hornet – officially called Vespa mandarinia, the species is native to East Asia – first prompted concern in the US and Canada in 2019, when the first specimens were reported in both countries.

That year, a dead hornet was found on a property in Blaine, a small community in Washington state near the Canadian border, while others were spotted around Nanaimo, BC.

The Asian giant hornet typically measures an inch-and-a-half in length and it is distinguished by a large head that is a mix of yellow and orange. US authorities said its sting is much more dangerous than that of bees or wasps and can cause “severe pain, swelling, necrosis and, in rare cases, even death” in some humans.

They can pose a risk to livestock and other insects, as well as honeybees, which are already facing dwindling numbers and for which the hornets “have a voracious appetite”, according to Washington state authorities. “A small group of Asian giant hornets can kill an entire honeybee hive in a matter of hours,” the Washington State Department of Agriculture (WSDA) said.

That is why experts have said it is important for the invasive species, which is not native to North America, to be eradicated.

The first Asian giant hornets in the US and Canada were discovered in 2019 [Karla Salp/Washington State Department of Agriculture/Handout via Reuters]

First US nest

In October of last year, Washington State Department of Agriculture (WSDA) entomologists discovered the US’s first Asian giant hornet nest, also in the town of Blaine.

Authorities said they witnessed dozens of hornets going in and out of the nest, which was found in a tree cavity about 10 feet (three metres) off the ground. Experts had successfully affixed radio trackers to three hornets that had been trapped in the area, and one led them back to the nest.

A day after the discovery, the authorities vacuumed 98 hornets out of the nest. They later said they found 500 live specimens at various stages of development in the nest, The Associated Press news agency reported.

Sven Spichiger, managing entomologist at WSDA, said in a news briefing last month that more than 1,200 people across Washington state hung homemade traps last year as part of the state’s efforts to track the Asian giant hornets.

This year, Spichiger said the WSDA hopes to have one trap for every square kilometre in its target areas – or approximately 1,500 traps total. People can use a mixture of orange juice and rice wine, or another mixture of water and brown sugar, as bait, he added – and they are most likely to trap a hornet beginning in July.

Sven Spichiger, Washington State Department of Agriculture managing entomologist, displays a canister of Asian giant hornets vacuumed from a nest in Blaine on October 24, 2020 [Elaine Thompson/AP Photo]

“To me, hanging a trap actually protects you. It lets you know that there’s something in the area and it contains it in such a way that you can then call [the authorities] and we can do something about it,” Spichiger told reporters last month.

What can be dangerous, he said, is not knowing the hornets are around and inadvertently getting too close. “You get your lawnmower maybe a little too close and you’re overwhelmed before you even know what’s happening, that’s to me what the real danger is.”

Coordinated effort

Officials in the US and Canada said they plan to work together to contain the hornets this year.

In Canada, six Asian giant hornet specimens have been found in the Fraser Valley of southwest BC, and a nest was destroyed in Nanaimo in September 2019.

Van Westendorp said in the early spring, the only Asian giant hornets people could potentially see would be mated queens that were born and mated last fall, wintered alone, and are now emerging because the weather is warmer. Those queens will try to start a nest on their own.

The queen’s offspring – female worker hornets that are smaller in size – will help her build a larger nest, he explained, a process that will continue through the summer. In late summer, the hornets begin to prey on honeybees.

Van Westendorp said experts will be focused on the Fraser Valley area in their search for the species, as well as on Vancouver Island, where no sightings were reported in 2020. “So we have high hopes that if that continues to be negative that by the end of this year we can declare Vancouver Island free of the Asian giant hornet,” he said.

But Van Westendorp had a message for anyone who may come across one: “Don’t be heroic.”

Take a photograph of the hornet and contact the authorities, he said, because they “can pose a serious hazard if you don’t know what you’re doing … We don’t want that to happen.”

Source: Al Jazeera