Researchers worry 'murder hornets' could spread through B.C., threatening honeybees
TORONTO -- Researchers worry that the west coast of North America -- including British Columbia -- serves as a suitable climate for ‘murder hornets’ to live and potentially harm the local honeybee population, if they are not contained.
The study, published Tuesday in Proceedings of the National Academy of Sciences, looked at more than 200 records from Japan, South Korea and Taiwan to determine what habitat characteristics these insects tend to thrive in. The researchers found that the hornets prefer warm summers and mild winters, with high amounts of rainfall, making the east and west coasts of North America, much of Europe, parts of South America, eastern Australia and most of New Zealand some ideal climates for the hornets to thrive.
"These predictions are scientific sleuthing," Javier Illan, an entomologist at Washington State University and a collaborator on the study, said in a news release. "We're making an educated guess on how fast and far these insects can move, their rate of success in establishing a nest, and offering different scenarios, from least bad to worst. No one has done this before for this species."
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According to a map attached to the study, southern Ontario, southern Quebec and Atlantic Canada are also considered suitable areas for the murder hornet, but they would have to be transported there first, likely through accidental human transport.
"It's easy for some species to get moved accidentally from one side of the country to the other, even if there's a large swathe of unacceptable habitat in between," said Washington State Department of Agriculture scientist Chris Looney.
The Asian giant hornet, popularly called the “murder hornet,” can grow to five centimetres long and is typically native to Japan, Korea and Taiwan. These hornets pose a particular threat to honeybees, as they are known to destroy entire beehives during the summer and fall.
Asian honeybees have developed a defence known as the “hot defensive bee balls,” where the bees will gang up on a murder hornet and vibrate their wings to create enough heat that kills the hornet. Honeybees in North America have not developed this defence, making an established population of murder hornets in the region a real threat to already dwindling honeybee populations.
The researchers note that it is still unclear if the hornets are established in North America, but they have recently been reported in Washington state and British Columbia. They suggest that if the murder hornets are allowed to spread in western North America, the region could see a loss of up to half of their beehives, “forcing beekeepers to invest heavily in hornet management or relocate their operations.”
As a result, the researchers are calling for “extensive monitoring and eradication efforts” throughout western North America to help get rid of any murder hornets in the region.
"Preventing the establishment and spread of Asian giant hornet in western North America is critical for protecting bees and beekeepers," said David Crowder, an entomologist at Washington State University and a collaborator on the study. "Our study can inform strategies to monitor and eradicate these invaders before they become established."
The researchers estimate these hornets can fly up to 111 kilometres a year, meaning they could spread from Washington to Oregon and British Columbia within the next 20 years. They do caution that this dispersion is just an estimate, however.
"We know queens come out of their nest in the fall, mate, and fly--somewhere," said Looney. “Nobody knows how far they fly, or if they fly repeatedly. We don't know if they set up nests in the spring near where they hibernated, or if they start flying again. These are some of the things that make predicting natural dispersal a challenge."