Mahogany Dun vs Small Minnow Mayfly

Side-by-side species comparison

Attribute Mahogany Dun Small Minnow Mayfly
Scientific Name Isonychia harperi Callibaetis ferrugineus
Order Ephemeroptera Ephemeroptera
Family Isonychiidae Baetidae
Size 13-17 mm 7-11 mm
Habitat Rivers & Streams Ponds & Lakes
Diet Omnivores Detritivores
Regions North America North America
Conservation Least Concern Least Concern

Mahogany Dun

A large reddish-brown mayfly with impressive filter-feeding forelegs. Nymphs prefer moderate to fast riffles with clean gravel substrates.

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Did You Know?

Adults hold their forelegs forward in flight, making them easy to identify on the wing.

Small Minnow Mayfly

A mottled brown mayfly common in still waters across North America. Nymphs are excellent swimmers that mimic small minnows.

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Did You Know?

It can produce up to three generations per year in warm climates.