Giant Salmonfly vs Small Brown Forestfly

Side-by-side species comparison

Attribute Giant Salmonfly Small Brown Forestfly
Scientific Name Pteronarcys princeps Nemoura avicularis
Order Plecoptera Plecoptera
Family Pteronarcyidae Nemouridae
Size 35-50 mm 5-8 mm
Habitat Mountains Woodlands
Diet Detritivores Detritivores
Regions North America Europe
Conservation Least Concern Least Concern

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.

Small Brown Forestfly

A small brown stonefly of European woodland streams that emerges in spring. Nymphs are detritivores feeding on submerged leaf litter.

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Did You Know?

Adults fold their wings flat over the body like a fan, unlike most stoneflies that fold wings along the sides.