Autumn Dun vs Light Cahill Mayfly

Side-by-side species comparison

Attribute Autumn Dun Light Cahill Mayfly
Scientific Name Leptophlebia marginata Heptagenia solitaria
Order Ephemeroptera Ephemeroptera
Family Leptophlebiidae Heptageniidae
Size 10-14 mm 9-13 mm
Habitat Woodlands Rivers & Streams
Diet Detritivores Omnivores
Regions Europe North America
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.

Light Cahill Mayfly

A pale-colored mayfly highly prized by fly fishers for imitating hatches. Nymphs prefer moderate current over gravel substrates.

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Did You Know?

The Light Cahill dry fly pattern, designed to mimic this species, has been used since the 1880s.