Northern Stonefly vs Giant Stonefly

Side-by-side species comparison

Attribute Northern Stonefly Giant Stonefly
Scientific Name Nemoura arctica Pteronarcys californica
Order Plecoptera Plecoptera
Family Nemouridae Pteronarcyidae
Size 6-10 mm 30-50 mm body
Habitat Rivers & Streams Rivers & Streams
Diet Herbivores Herbivores
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 Stonefly

Large aquatic insects whose nymphs require pristine, cold, oxygen-rich streams. Adults are poor fliers and stay near water. Important food source for trout.

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Did You Know?

Stonefly nymphs are so sensitive to water pollution that their presence is used by scientists as a living indicator of water quality — no stoneflies means polluted water.