Spotted Hydropsyche Caddisfly vs Western Grannom Caddis

Side-by-side species comparison

Attribute Spotted Hydropsyche Caddisfly Western Grannom Caddis
Scientific Name Hydropsyche slossonae Brachycentrus occidentalis
Order Trichoptera Trichoptera
Family Hydropsychidae Brachycentridae
Size 10-14 mm 9-12 mm
Habitat Rivers & Streams Rivers & Streams
Diet Detritivores Omnivores
Regions Eastern North America Europe
Conservation Least Concern Least Concern

Spotted Hydropsyche Caddisfly

A net-spinning caddisfly with tan to brown mottled wings. Larvae build intricate silken nets between rocks to capture drifting food particles in stream currents.

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Did You Know?

The mesh size of their silk nets varies by species, allowing different species to partition food resources in the same stream.

Western Grannom Caddis

A widespread European caddisfly forming mass emergences in spring on alkaline rivers. Larvae build four-sided tapering cases and filter-feed in riffles.

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Did You Know?

Spring Grannom hatches on English chalk streams can darken the sky with millions of emerging adults.