Giant Michigan Mayfly vs Trico Mayfly

Side-by-side species comparison

Attribute Giant Michigan Mayfly Trico Mayfly
Scientific Name Hexagenia bilineata Tricorythodes stygiatus
Order Ephemeroptera Ephemeroptera
Family Ephemeridae Leptohyphidae
Size 18-28 mm 3-6 mm
Habitat Rivers & Streams Rivers & Streams
Diet Detritivores Detritivores
Regions North America North America
Conservation Least Concern Least Concern

Giant Michigan Mayfly

A large burrowing mayfly with two dark stripes on its thorax. Nymphs dig into soft clay and silt bottoms of large rivers.

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Did You Know?

Mass emergences along the Great Lakes have caused road closures due to the slippery accumulation of millions of dead adults.

Trico Mayfly

A tiny mayfly that forms enormous morning spinner falls over calm streams and rivers. Males have distinctive white bodies with black thoraxes.

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Did You Know?

Trico spinner falls create such dense blankets of spent mayflies on the water surface that trout gorge themselves to satiation.