British Columbia's beekeepers say they're on guard after a nest of Asian giant hornets was found and destroyed Thursday just south of the border in Washington state.
The massive hornets can grow up to four centimetres long, the size of a small hummingbird, and kill entire honeybee hives — as well as deliver a potentially dangerous sting to people, says a provincial government bee expert.
"They are the largest hornets in the world. Their sting can cause quite a bit of damage," Paul van Westendorp, with B.C.'s agriculture ministry, told CBC News. "We all react to these venoms differently."
He said Japan, where they are more common, sees dozens of deaths from Asian giant hornet stings every year.
But he said the public should not be alarmed since the hornets are apex predators, meaning they are at the top of their food chain and therefore are relatively few in number.
While there won't be "hordes" of swarming hornets, he said, people should be careful not to disturb their nests, which are often in holes in the ground or trees.
They become aggressive only in defence of their homes, he said.
He says the province is working closely with counterparts south of the border, and beekeepers locally.
The hornets were first found on this continent several years ago, on Vancouver Island. The recent finding in Blaine, Wash., has B.C. honey producers vigilant.
Hobby beekeeper Thomas Schmitz is president of the Surrey Beekeepers Association. He has 15 hives located just across the border from Blaine.
"Of course, we hope this hornet doesn't cross the border," Schmitz told CBC News. "These hornets could enter the honey bee colony and not only kill individuals, but more importantly kill the queen.
"I'm aware of the potential threat, but I'm not concerned at this point."
The Washington State Department of Agriculture said Thursday the hornet nest was discovered "in the base of a dead alder tree" in rural Whatcom County, east of Blaine, just 400 metres south of the Canadian border.
"This detection proves how important public reporting continues to be," said the department's managing entomologist, Sven Spichiger, in a statement. "We expect there are more nests out there and, like this one, we hope to find them before they can produce new queens."
In B.C., Van Westendorp believes most of the province's beekeepers are well prepared to keep hornets out of hives, using "ingenuity" such as traps and barriers — and hopes the public will be vigilant in reporting any sightings, and avoiding accidentally disturbing the giant insects' nests.