As if the COVID-19 pandemic wasn’t enough, now the insect world is throwing ‘murder hornets’ at North Americans, including in British Columbia.
First spotted in Canada in September 2019 in Nanaimo, B.C., Asian giant hornets nest in the ground and feed only on insects, but may sting humans if their nests are disturbed. The hornets, spotted this year in Washington State close to the Canadian border, can be up to five centimetres in length and are considered an invasive species.
British Columbia officials have asked residents along the Canada-U.S. border, from Surrey to Aldergrove, to watch for the giant hornets this year.
According to experts from Western University, the so-called ‘murder hornets’ likely found their way to Canada and the U.S. through global trade — similar to how the emerald ash borer spread.
Graham Thompson, a Western biology professor, says the murder hornets pose a great threat to honey bees, which are already facing pressure from human activities.
“Honey bees have a lot of natural enemies. Bacteria, fungus, mites attack them and pose serious threats,” explains Thompson. “And we humans don’t do them any favours either by exposing them to lots of different chemicals and pesticides. So even though the Asian giant hornet … would just be entering the bottom of the list of what’s currently threatening honey bees, it’s now on the list nonetheless.”
Brent Sinclair, also a biology professor at Western, says if the hornets get into a honey bee hive they will systematically eat their way through the population of the hive.
Honey bee expert Rob Currie from the University of Manitoba adds the invasive species is fairly concerning for the honey bee industry.
“These hornets are quite devastating to the species of honey bee we have in North America,” says Currie, department head of entomology. “In Asia, the honey bees there swarm and attack the hornet, but our European bees don’t have the same defense.”
According to Currie, the “slaughter phase” of the hornet’s life cycle occurs near the end of the year — August or September — and involves the hornet attacking the colony and throwing dead worker bees out near the entrance.