Common Water Penny vs Microcaddisfly

Side-by-side species comparison

Attribute Common Water Penny Microcaddisfly
Scientific Name Psephenus herricki Hydroptila sparsa
Order Coleoptera Trichoptera
Family Psephenidae Hydroptilidae
Size 4-6 mm (adults); 6-10 mm (larvae) 3-4 mm
Habitat Rivers & Streams Rivers & Streams
Diet Omnivores Omnivores
Regions Eastern North America Europe, North America
Conservation Least Concern Least Concern

Common Water Penny

A small aquatic beetle whose larvae are flattened and round like a copper penny, clinging to rocks in fast streams. Adults are terrestrial and short-lived.

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Did You Know?

Larvae are so flat they can cling to rocks in torrential currents that would wash away most other insects.

Microcaddisfly

One of the smallest caddisflies, with adults only 3-4 mm long. Larvae build tiny purse-shaped cases from silk and algae on submerged rocks.

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Did You Know?

Microcaddisfly larvae build a new case for each instar, and their final pupal case is so small it is barely visible to the naked eye.