New ‘murder hornet’ reported in Washington state, but specimen’s origin puzzles entomologists

A dead Asian giant hornet, next to a can of beer for scale. (Photo via WSDA)

They’re baaaack? Hopefully, not quite.

Less than a year after the Washington State Department of Agriculture located and eradicated a dangerous nest of Asian giant hornets in the northwestern part of the state, entomologists have confirmed the first report of a so-called “murder hornet” for 2021.

The deceased hornet was found near Marysville in Snohomish County by a resident who reported it on June 4 through the WSDA’s online Hornet Watch Report Form. Entomologists retrieved the very dried out specimen, observed it as a male hornet and noticed different coloring than specimens collected last year in North America.

The insect was positively identified as Vespa mandarinia on June 11, but testing and color variation indicate that it appears to be unrelated to the Whatcom County or Canadian Asian giant hornet introductions, the WSDA said in a news release on Wednesday.

The department reported that entomologists believe the specimen is an old hornet from a previous season that wasn’t discovered until now. New males usually don’t emerge until at least July. WSDA also said “there is no obvious pathway for how the hornet got to Marysville.”

“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.”

(Photo via WSDA)

The first ever Asian giant hornet nest found in the U.S. was located on a property in Blaine, Wash., last October.

Scientists were trapping hornet and attempting to track them back to a nest for weeks, tagging them with tiny radio trackers. One finally led the WSDA to the nest in the cavity of a tree, which was removed on Oct. 24.

Vikram Iyer, a PhD student at the University of Washington in the Paul G. Allen School of Computer Science & Engineering’s Networks and Mobile Systems Lab, won the Innovation of the Year award at the 2021 GeekWire Awards for his work on tiny sensors and tracking technology that helped inform the search for the nest.

The Asian giant hornet is the world’s largest species of hornet. The first-ever sightings occurred in the U.S. in December in Northwest Washington state. The hornets are known to attack and destroy honeybee hives during a “slaughter phase” where they kill bees by decapitating them.

USDA says it will continue to provide technical expertise and monitor the situation in the state and it continues to encourage citizens to report suspected sightings online at agr.wa.gov/hornets, by emailing [email protected], or calling 1-800-443-6684.

Previously:

Photos: Tree deep in Asian giant hornet nest, entomologists recover ‘chewed off’ radio tracker

Using radio trackers, scientists locate ‘murder hornet’ nest in Washington state — first ever in U.S.

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Science Asian giant hornet Insects Murder hornet Washington state department of agriculture