Snail-Case Caddis vs Small Ballast Caddisfly

Side-by-side species comparison

Attribute Snail-Case Caddis Small Ballast Caddisfly
Scientific Name Helicopsyche borealis Silo pallipes
Order Trichoptera Trichoptera
Family Helicopsychidae Goeridae
Size 5-7 mm 7-10 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Omnivores
Regions North America Europe
Conservation Least Concern Least Concern

Snail-Case Caddis

A remarkable caddisfly whose larvae build coiled cases from sand grains that closely resemble tiny snail shells. It is widespread in North American streams.

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Did You Know?

Its spiral case is so convincing that early naturalists classified the larvae as snails rather than insects.

Small Ballast Caddisfly

A small caddisfly that cements large pebbles to its mineral case for ballast in fast water. Found exclusively in clean calcareous streams.

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Did You Know?

Larvae select ballast stones of remarkably uniform size relative to their body mass.