Japanese Diving Beetle vs Excavated Rove Beetle

Side-by-side species comparison

Attribute Japanese Diving Beetle Excavated Rove Beetle
Scientific Name Cybister japonicus Omalium excavatum
Order Coleoptera Coleoptera
Family Dytiscidae Staphylinidae
Size 30-38 mm 3-4 mm
Habitat Ponds & Lakes Gardens
Diet Omnivores Herbivores
Regions Japan, Korean Peninsula Europe, introduced to North America
Conservation Vulnerable Least Concern

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.

Excavated Rove Beetle

A small, brownish omaline rove beetle with distinctive excavations on the pronotum. It frequents decaying vegetation and is particularly associated with compost heaps and grass clippings.

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Did You Know?

This species thrives in the heat-generating centers of compost heaps, tolerating temperatures that would be lethal to many other insects.