Autumn Dun vs Yellow May Dun

Side-by-side species comparison

Attribute Autumn Dun Yellow May Dun
Scientific Name Leptophlebia marginata Heptagenia sulphurea
Order Ephemeroptera Ephemeroptera
Family Leptophlebiidae Heptageniidae
Size 10-14 mm 10-15 mm
Habitat Woodlands Rivers & Streams
Diet Detritivores Omnivores
Regions Europe Europe
Conservation Least Concern Least Concern

Autumn Dun

A dark-winged mayfly that emerges in spring despite its common name. Nymphs inhabit slow-flowing sections of woodland streams among leaf litter.

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Did You Know?

Its common name refers to the brownish autumnal color of the adult, not its emergence season.

Yellow May Dun

A bright sulfur-yellow mayfly common across European rivers during early summer. Its flat nymphs are adapted to fast-flowing water on stony substrates.

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Did You Know?

The striking yellow color of this mayfly makes it one of the most easily recognizable species on European rivers.