Sulphur Mayfly vs Cascade Ice Crawler

Side-by-side species comparison

Attribute Sulphur Mayfly Cascade Ice Crawler
Scientific Name Ephemerella dorothea Grylloblatta chirurgica
Order Ephemeroptera Grylloblattodea
Family Ephemerellidae Grylloblattidae
Size 6-9 mm 15-25 mm
Habitat Rivers & Streams Caves
Diet Omnivores Omnivores
Regions North America North America
Conservation Least Concern Vulnerable

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.

Cascade Ice Crawler

A North American ice crawler found in the Cascade Range of Washington and Oregon. It lives in volcanic talus slopes near permanent snowfields.

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Did You Know?

Their preferred body temperature is around 1°C, making them among the most cold-adapted insects on Earth.