Northern Stonefly vs Giant Salmonfly

Side-by-side species comparison

Attribute Northern Stonefly Giant Salmonfly
Scientific Name Nemoura arctica Pteronarcys princeps
Order Plecoptera Plecoptera
Family Nemouridae Pteronarcyidae
Size 6-10 mm 35-50 mm
Habitat Rivers & Streams Mountains
Diet Herbivores Detritivores
Regions Arctic Scandinavia, Finland, northern Russia, Iceland, Arctic Canada North America
Conservation Least Concern Least Concern

Northern Stonefly

A small, dark brown stonefly with two long cerci at the tip of the abdomen. Adults hold their wings flat over the body. Nymphs develop in cold, well-oxygenated streams and are indicators of clean water.

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Did You Know?

Stonefly nymphs are so sensitive to pollution that their presence in a stream is used as an indicator of excellent water quality.

Giant Salmonfly

A massive stonefly of western mountain rivers with a three-year nymphal life cycle. Nymphs feed on decomposing leaf material in cold streams.

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Did You Know?

Adults are among the largest flying insects in North America and can barely sustain flight due to their weight.