Mahogany Dun vs South American Giant Mayfly

Side-by-side species comparison

Attribute Mahogany Dun South American Giant Mayfly
Scientific Name Isonychia harperi Campsurus major
Order Ephemeroptera Ephemeroptera
Family Isonychiidae Polymitarcyidae
Size 13-17 mm 15-25 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Omnivores
Regions North America South 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.

South American Giant Mayfly

A large tropical mayfly found in South American rivers and floodplains. Males have distinctive elongated forelegs used for grasping females during mating flights.

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Did You Know?

Its mass emergences from Amazonian rivers provide a critical food pulse for fish and birds.