Western Grannom Caddis vs Weighted Casemaker

Side-by-side species comparison

Attribute Western Grannom Caddis Weighted Casemaker
Scientific Name Brachycentrus occidentalis Goera pilosa
Order Trichoptera Trichoptera
Family Brachycentridae Goeridae
Size 9-12 mm 9-13 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Detritivores
Regions Europe Europe
Conservation Least Concern Least Concern

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.

Weighted Casemaker

A caddisfly that attaches heavy ballast stones to the sides of its case for stability. Larvae are found in fast-flowing stony streams.

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Did You Know?

The ballast stones can weigh several times more than the larva itself, preventing displacement by floods.