March Brown Mayfly vs Hairy Whirligig Beetle

Side-by-side species comparison

Attribute March Brown Mayfly Hairy Whirligig Beetle
Scientific Name Rhithrogena germanica Orectochilus villosus
Order Ephemeroptera Coleoptera
Family Heptageniidae Gyrinidae
Size 10-14 mm 5-7 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Omnivores
Regions Europe Europe
Conservation Near Threatened Least Concern

March Brown Mayfly

A spring-emerging mayfly with a brownish body and two tails, historically important to European fly fishing. Its flat nymphs cling to rocks in fast water.

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Did You Know?

This species has declined significantly in many European rivers due to pollution and is now considered an indicator of water quality.

Hairy Whirligig Beetle

A nocturnal whirligig beetle covered in fine golden hairs that trap air underwater. Unlike other whirligigs it hides under stones by day.

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Did You Know?

It is the only European whirligig beetle that is primarily nocturnal rather than diurnal.