Large Stonefly vs Giant Salmonfly

Side-by-side species comparison

Attribute Large Stonefly Giant Salmonfly
Scientific Name Perla bipunctata Pteronarcys princeps
Order Plecoptera Plecoptera
Family Perlidae Pteronarcyidae
Size 20-30 mm 35-50 mm
Habitat Rivers & Streams Mountains
Diet Predators Detritivores
Regions Europe North America
Conservation Near Threatened Least Concern

Large Stonefly

One of the largest European stoneflies with a distinctive pair of pale spots on its head. Its predatory nymphs live among stones in fast-flowing rivers.

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Did You Know?

Large stonefly nymphs require three years to complete development, making them particularly vulnerable to long-term changes in 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.