Black Sedge vs American Grannom

Side-by-side species comparison

Attribute Black Sedge American Grannom
Scientific Name Silo nigricornis Brachycentrus americanus
Order Trichoptera Trichoptera
Family Goeridae Brachycentridae
Size 7-9 mm body 9-13 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Omnivores
Regions Europe North America
Conservation Least Concern Least Concern

Black Sedge

A caddisfly whose larvae build heavy cases from sand grains cemented with silk. Found in clean, stony streams. Cases have lateral flanges of larger stones for ballast.

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Did You Know?

Larval cases have added flanges of larger stones that act as ballast, preventing the case from being swept away.

American Grannom

A case-building caddisfly whose larvae attach their cases to rocks in fast current and filter-feed. Cases are chimney-shaped and built from silk and plant fragments.

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Did You Know?

Larvae can switch between filter-feeding and scraping algae depending on current speed.