Arctic Weevil vs Japanese Diving Beetle

Side-by-side species comparison

Attribute Arctic Weevil Japanese Diving Beetle
Scientific Name Otiorhynchus arcticus Cybister japonicus
Order Coleoptera Coleoptera
Family Curculionidae Dytiscidae
Size 5-8 mm 30-38 mm
Habitat Tundra & Arctic Ponds & Lakes
Diet Root Feeders Omnivores
Regions Arctic Scandinavia, northern Russia, Svalbard, Iceland Japan, Korean Peninsula
Conservation Least Concern Vulnerable

Arctic Weevil

A small, dark, flightless weevil with a short broad snout and rough-textured elytra. Adults are nocturnal and hide under stones during the day. Larvae feed on plant roots in tundra soil.

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Did You Know?

Being flightless, this weevil relies entirely on walking to disperse, which means isolated Arctic populations can be genetically distinct.

Japanese Diving Beetle

A large diving beetle native to Japan, once common but now increasingly rare. It has suffered severe declines due to habitat loss and invasive species.

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Did You Know?

The American bullfrog, introduced to Japan, is a major predator of this beetle and a key driver of its decline.