Cahill Mayfly vs Arctic Mayfly

Side-by-side species comparison

Attribute Cahill Mayfly Arctic Mayfly
Scientific Name Stenacron interpunctatum Baetis bundyae
Order Ephemeroptera Ephemeroptera
Family Heptageniidae Baetidae
Size 8-12 mm 5-8 mm
Habitat Rivers & Streams Tundra & Arctic
Diet Detritivores Omnivores
Regions North America Arctic Canada, Alaska, northern Scandinavia
Conservation Least Concern Least Concern

Cahill Mayfly

A cream-to-tan colored mayfly found throughout eastern North America. It is named after the classic Light Cahill fly fishing pattern it inspired.

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Did You Know?

The Light Cahill fly pattern, inspired by this mayfly, has been a staple of American fly fishing since the 1880s.

Arctic Mayfly

A small, delicate mayfly with transparent wings and two long tail filaments. Nymphs are agile swimmers in cold Arctic streams. Adults emerge for a very brief mating flight during the short Arctic summer.

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Did You Know?

Adult mayflies live only a few hours to a few days, just long enough to mate and lay eggs before dying.