Diving Beetle vs Mahogany Dun

Side-by-side species comparison

Attribute Diving Beetle Mahogany Dun
Scientific Name Dytiscus marginalis Isonychia harperi
Order Coleoptera Ephemeroptera
Family Dytiscidae Isonychiidae
Size 27-35 mm 13-17 mm
Habitat Rivers & Streams Rivers & Streams
Diet Predators Omnivores
Regions Europe, Asia North America
Conservation Least Concern Least Concern

Diving Beetle

A large, streamlined aquatic beetle with an olive-green body bordered in yellow. It carries an air bubble under its elytra and is a voracious underwater predator.

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Did You Know?

Great diving beetles can stay submerged for extended periods by trapping a silvery air bubble under their wing covers that functions like a gill.

Mahogany Dun

A large reddish-brown mayfly with impressive filter-feeding forelegs. Nymphs prefer moderate to fast riffles with clean gravel substrates.

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Did You Know?

Adults hold their forelegs forward in flight, making them easy to identify on the wing.