Murder hornets ... again?

Entomologists from the Washington State Department of Agriculture (WSDA) and the U.S. Department of Agriculture (USDA) have confirmed the first report of an Asian giant hornet for 2021. This is the first confirmed report from Snohomish County and appears to be unrelated to the 2019/2020 Asian giant hornet introductions in Canada and Whatcom County.

The 2-inch-long invasive insects, first found near the U.S.-Canadian border in December 2019, are native to Asia and pose a threat to honeybees and native hornet species. While not particularly aggressive toward humans, their sting is extremely painful and repeated stings, though rare, can kill.

The world’s largest hornet is much more of a threat to honeybees that are relied on to pollinate crops. They attack hives, destroying them in mere hours and decapitating bees in what scientists call their “slaughter phase.” How they got here from Asia is unclear, although it is suspected they travel on cargo ships.

Entomologists believe that the specimen found is an old hornet from a previous season that wasn’t discovered until now. New males usually don’t emerge until at least July. There is no obvious pathway for how the hornet got to this destination.

“The find is perplexing because it is too early for a male to emerge,” said Dr. Osama El-Lissy, deputy administrator for the USDA Plant Protection and Quarantine program. “Last year, the first males emerged in late July, which was earlier than expected. However, we will work with WSDA to survey the area to verify whether a population exists in Snohomish County. USDA will continue to provide technical expertise and monitor the situation in the state. USDA has already provided funding for survey and eradication activities as well as research into lures and population genetics.”

“This new report continues to underscore how important public reporting is for all suspected invasive species, but especially Asian giant hornet,” Sven Spichiger, WSDA managing entomologist said. “We’ll now be setting traps in the area and encouraging citizen scientists to trap in Snohomish and King counties. None of this would have happened without an alert resident taking the time to snap a photo and submit a report.”