Thin-neck Cave Beetle vs Icelandic Water Beetle

Side-by-side species comparison

Attribute Thin-neck Cave Beetle Icelandic Water Beetle
Scientific Name Pseudanophthalmus parvicollis Agabus bipustulatus
Order Coleoptera Coleoptera
Family Carabidae Dytiscidae
Size 4-5 mm 9-12 mm
Habitat Caves Tundra & Arctic
Diet Detritivores Predators
Regions United States Iceland, Scandinavia, northern Russia, subarctic Europe, Arctic Canada
Conservation Endangered Least Concern

Thin-neck Cave Beetle

A narrowly endemic cave beetle with a distinctively slender pronotum. It inhabits caves in the Appalachian karst region.

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Did You Know?

Its narrow neck (pronotum) helps it squeeze through tiny fissures in cave rock.

Icelandic Water Beetle

A medium-sized, oval, dark brown diving beetle found in cold ponds and lakes. It carries a silvery air bubble under its elytra for breathing underwater. Adults are strong fliers and can colonize isolated Arctic ponds.

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Did You Know?

This beetle is one of the most widespread diving beetles in the Arctic and can fly long distances to colonize new ponds created by permafrost thaw.