More than 500 Asian giant hornets have been collected from the first known nest of the invasive species in the United States, officials announced Tuesday.
Washington State Department of Agriculture entomologists discovered the nest of "murder hornets" last month in a tree in Blaine, north of Seattle, near the Canadian border.
After eradicating the nest, during which the crew vacuumed out nearly 100 hornets, the entomologists removed the portion of the tree with the nest and opened it the following week to collect any hornets that had remained. The crew had pumped carbon dioxide into the tree during the nest removal to kill or anesthetize any remaining hornets, and many were still alive, officials said.
Upon opening the tree, the team determined that the nest was about 14 inches long and up to 9 inches wide. Hornets in various life stages were collected, including approximately 200 queens, Sven Spichiger, the agency's managing entomologist, told reporters during a virtual press briefing Tuesday.
"As far as we can tell, we got there just in time," Spichiger said. "We know from the literature that a small percentage of these will go on to form colonies next year, should they have been given the chance to escape."
In total, the nest contained 190 larvae, 112 worker (female) bees, nine drone (male) bees and six unhatched eggs, Spichiger said. There were 76 queen bees, and 108 capped cells with pupae, most of which were believed to be of new virgin queens.