Giant Stonefly vs Japanese Giant Stonefly

Side-by-side species comparison

Attribute Giant Stonefly Japanese Giant Stonefly
Scientific Name Pteronarcys californica Oyamia lugubris
Order Plecoptera Plecoptera
Family Pteronarcyidae Perlidae
Size 30-50 mm body 25-35 mm
Habitat Rivers & Streams Mountains
Diet Herbivores Predators
Regions North America Japan
Conservation Least Concern Least Concern

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.

Japanese Giant Stonefly

A large predatory stonefly found in mountainous streams of Japan. Nymphs have powerful mandibles for capturing prey in swift currents.

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Did You Know?

It is an indicator of pristine water quality in Japanese mountain streams.