Cottonwood Borer vs Grannom Caddisfly

Side-by-side species comparison

Attribute Cottonwood Borer Grannom Caddisfly
Scientific Name Plectrodera scalator Brachycentrus subnubilus
Order Coleoptera Trichoptera
Family Cerambycidae Brachycentridae
Size 25-40 mm 8-12 mm
Habitat Rivers & Streams Rivers & Streams
Diet Root Feeders Detritivores
Regions Central and eastern United States Europe
Conservation Least Concern Least Concern

Cottonwood Borer

A large longhorn beetle with bold black and white patterning and long antennae. Its larvae bore into the roots and lower trunks of cottonwood and willow trees.

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Did You Know?

When handled, it produces a loud squeaking sound by rubbing parts of its thorax together.

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.

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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.