Murder hornets may spread down West Coast if not contained in Washington, research says

Murder hornets have invaded Washington state — and they could spread down the West Coast, researchers said.

Washington State University researchers predicted that if Asian giant hornets, also called murder hornets, become more common in the state, they could make a home in other parts of the U.S. and globally.

“Sharing their discoveries in a newly published article in the Proceedings of the National Academy of Sciences, the team found that if the world’s largest hornet gains a foothold in Washington state, it could spread down much of the west coast of the United States,” Washington State University said in a news release.

The Asian giant hornet could also find habitat in the eastern seaboard and parts of Africa, Australia, Europe and South America, researchers said.

“These predictions are scientific sleuthing,” Javier Illan, a WSU entomologist, said in the 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.”

Murder hornets thrive in places that have a warmer summer and mild winters. They also like lots of rain, and extreme heat can be lethal, researchers said.

They were first spotted in Washington state in 2019, and have been seen multiple times in 2020, the Washington State Department of Agriculture said.

“(The) Asian giant hornet attacks and destroys honeybee hives,” the Department of Agriculture said on its website. “A few hornets can destroy a hive in a matter of hours. The hornets enter a ‘slaughter phase’ where they kill bees by decapitating them. They then defend the hive as their own, taking the brood to feed their own young.”

Based on what kind of environment the species has typically liked, suitable habitat for the hornet can be in parts of the U.S. west and east coasts, the WSU researchers said. If murder hornets become established in an area, they could have “negative impacts on the environment, economy, and public health,” according to the Washington Department of Agriculture.

“Much of the interior of the U.S. is inhospitable to the hornet due to extremes of heat, cold, and low rainfall,” WSU researchers said in the news release. “This includes the eastern parts of Washington state and British Columbia, as well as California’s Central Valley, all of which have major fruit and nut crops that rely on honey bee pollination.”

Researchers used data from similar species to predict how far Asian giant hornets could spread without containment. They could go into southern Washington and Oregon. In a “worst-case scenario,” researchers found that the hornets could go throughout western Washington and Oregon in 20 years or fewer.

“Preventing the establishment and spread of Asian giant hornet in western North America is critical for protecting bees and beekeepers,” said David Crowder, associate professor, WSU Department of Entomology. “Our study can inform strategies to monitor and eradicate these invaders before they become established.”

This story was originally published September 23, 2020 at 1:55 PM with the headline "Murder hornets may spread down West Coast if not contained in Washington, research says."