The first time the hornets were detected in North America was in B.C. in August 2019 and confirmed in Washington state later that year
The world’s largest hornet, an invasive breed dubbed the “murder hornet” for its dangerous sting and ability to slaughter a honeybee hive in a matter of hours, has been declared eradicated in the U.S., five years after being spotted for the first time in B.C. and Washington state near the Canadian border.
The first time the hornets were detected in North America was in B.C. in August 2019 and confirmed in Washington state in December 2019, when a Whatcom County resident reported a specimen.
A beekeeper also reported hives being attacked and turned over specimens in the summer of 2020. The hornets could have travelled to North America in plant pots or shipping containers, experts said.
The remains of a single giant hornet were found in B.C. again in 2021, near where four nests had recently been found and destroyed in Whatcom County.
DNA evidence suggested the populations found in B.C. and Washington were not related and appeared to originate from different countries. There also have been no confirmed reports in British Columbia since 2021, and the nonprofit Invasive Species Centre in Canada has said the hornet is also considered eradicated here.
The Washington and U.S. Departments of Agriculture announced the hornets’ eradication Wednesday, saying there had been no detections of the northern giant in Washington state since 2021.
The news represented an enormous success that included residents agreeing to place traps on their properties and reporting sightings, as well as researchers capturing a live hornet, attaching a tiny radio tracking tag to it with dental floss, and following it through a forest to a nest in an alder tree. Scientists destroyed the nest just as a number of queens were beginning to emerge, officials said.
“I’ve gotta tell you, as an entomologist — I’ve been doing this for over 25 years now, and it is a rare day when the humans actually get to win one against the insects,” Sven Spichiger, pest program manager of the Washington Sstate Department of Agriculture, told a virtual news conference.
The hornets, which can be five centimetres long and were formerly called Asian giant hornets, gained attention in 2013, when they killed 42 people in China and seriously injured 1,675.
In the U.S., around 72 people a year die from bee and hornet stings each year, according to data from the National Institutes of Health. Recent statistics on insect venom deaths in Canada are unavailable, but it’s been estimated a few people die each year from stings.
Northern giant hornets pose significant threats to pollinators and native insects. They can quickly wipe out a honeybee hive by decapitating the bees and then defending the hive as their own, taking the brood to feed their own young.
The hornet can sting through most beekeeper suits, deliver nearly seven times the amount of venom as a honeybee, and sting multiple times. At one point, the Washington Agriculture Department ordered special reinforced suits from China.
Washington is the only state that has had confirmed reports of northern giant hornets. Trappers found four nests in 2020 and 2021.
Spichiger said Washington will remain on the lookout, despite reporting the eradication. He noted that entomologists will continue to monitor traps in Kitsap County, where a resident reported an unconfirmed sighting in October but where trapping efforts and public outreach have come up empty.