Sulphur Mayfly vs Pale Evening Dun

Side-by-side species comparison

Attribute Sulphur Mayfly Pale Evening Dun
Scientific Name Ephemerella dorothea Heptagenia adaequata
Order Ephemeroptera Ephemeroptera
Family Ephemerellidae Heptageniidae
Size 6-9 mm 8-12 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Omnivores
Regions North America Europe
Conservation Least Concern Least Concern

Sulphur Mayfly

A small pale yellow mayfly that produces reliable evening hatches on eastern North American streams. One of the most important species for fly anglers.

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Did You Know?

Sulphur mayfly hatches are so predictable in timing that experienced anglers can arrive at the stream within minutes of the first emergence.

Pale Evening Dun

A flat-bodied mayfly whose nymphs press tightly against rocks in swift currents. Adults emerge at dusk during summer months.

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Did You Know?

Its extremely flattened body allows it to resist currents that would sweep away most other insects.