Iron Blue Dun vs Broad-shouldered Diving Beetle

Side-by-side species comparison

Attribute Iron Blue Dun Broad-shouldered Diving Beetle
Scientific Name Baetis muticus Dytiscus latissimus
Order Ephemeroptera Coleoptera
Family Baetidae Dytiscidae
Size 5-7 mm 36-44 mm
Habitat Rivers & Streams Ponds & Lakes
Diet Omnivores Omnivores
Regions Europe Northern Europe, Scandinavia
Conservation Least Concern Vulnerable

Iron Blue Dun

A small dark mayfly that hatches prolifically on cool overcast days. Nymphs are found clinging to stones in moderate to fast current.

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Did You Know?

Hatches are most prolific during rain and cold snaps, making it a favorite species for wet-weather anglers.

Broad-shouldered Diving Beetle

The largest European diving beetle and one of the largest aquatic beetles in the world. It inhabits clean, fish-poor lakes and is increasingly rare.

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Did You Know?

It is protected under the EU Habitats Directive and is one of the most endangered beetles in Europe.