Grannom Caddisfly vs Black Sedge

Side-by-side species comparison

Attribute Grannom Caddisfly Black Sedge
Scientific Name Brachycentrus subnubilus Silo nigricornis
Order Trichoptera Trichoptera
Family Brachycentridae Goeridae
Size 8-12 mm 7-9 mm body
Habitat Rivers & Streams Rivers & Streams
Diet Detritivores Omnivores
Regions Europe Europe
Conservation Least Concern Least Concern

Grannom Caddisfly

A small dark caddisfly that produces massive spring hatches on European rivers. Larvae build distinctive square-sectioned cases from silk and plant fibers.

💡

Did You Know?

Grannom hatches are so dense on some rivers that local people historically swept up mounds of dead adults to use as fertilizer.

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.

💡

Did You Know?

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