New species of weird-looking weevil discovered in Japan

A close up photograph of the new species of weevil, it has a long snout, is covered in hair-like projections, and has strange , long, bendy legs

The newly discovered species, Acicnemis ryukyuana, which the Cosmos newsroom agrees looks like the Muppet Gonzo. Credit: OIST

A new species of beetle has been discovered in the pristine forests of Japan’s Ishigaki Island and Yanbaru National Park in Okinawa Island.

And they look really weird.

Described in our newsroom by Cosmos journalist Ellen Phiddian as resembling a “sea urchin wearing a plague doctor mask” or “a crab that has been stretched a bit”, the new species has been named Acicnemis ryukyuana.

It is endemic to the Ryukyu Islands – a chain of subtropical islands between mainland Japan and Taiwan renowned for their remarkable biodiversity. The islands have a relatively isolated evolutionary history, so they’re home to some pretty distinctive and fascinating insects.

Researchers at the Okinawan Institute of Science and Technology (OIST) have been placing net traps to monitor insects on Okinawa Island since 2015 and preserve them in their insect collection.

Tarsal segment figure 850 — *Acicnemis ryukyuana’s* distinctive colours and leg shape: *Acicnemis ryukyuana* (A) can be distinguished by the yellow bands on its shoulders and the colour of its hardened fore wings. The shape of its leg segment (tarsal segment) is also very unique, as it is not strongly indented. In most *Acicnemis* species the same leg segment is heavily indented and heart shaped (shown here in *Acicnemis postica*, B). Credit: OIST

“The Ryukyu Islands offer an irresistible playground for taxonomists, rich in species which you only find here,” says entomologist Jake Lewis, Collection Manager in the OIST Environmental Science and Informatics Section.

“When I arrived at OIST in 2022, I dove headfirst into the OIST weevil collection. As I closely examined them, this species immediately caught my eye. It clearly belonged to the genus Acicnemis, but was unlike anything else described from East Asia.

“It’s elongated scales and unique coloration set this species apart from other known Japanese species.”

Weevils form one of the most diverse groups of animals on Earth, made up of approximately 5,800 genera and more than 60,000 described species.

Acic figure 850 — The newly discovered *Acicnemis ryukyuana* (A) and other *Acicnemis* species found in Okinawa. A) *Acicnemis ryukyuana*, B) *Acicnemis postica*, C) *Acicnemis azumai*, D) *Acicnemis exilis*, E) *Acicnemis maculaalba*, and F) *Acicnemis kiotoensis*. Credit: OIST

The genus Acicnemis already contains over 180 species, so confirming the discovery of a new species was no easy feat and involved a thorough examination of the existing literature and museum collections.

“Based on the unique set of features observed in this new species, A. ryukyuana appears to be closely related to some other species in southeast Asia, however DNA analyses will be required to confirm this,” says Lewis.

Originally published by Cosmos as That’s a beetle?! New species of weird-looking weevil discovered in Japan

Imma Perfetto

Imma Perfetto is a science journalist at Cosmos. She has a Bachelor of Science with Honours in Science Communication from the University of Adelaide.

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