Common Water Penny vs Cockchafer

Side-by-side species comparison

Attribute Common Water Penny Cockchafer
Scientific Name Psephenus herricki Melolontha melolontha
Order Coleoptera Coleoptera
Family Psephenidae Scarabaeidae
Size 4-6 mm (adults); 6-10 mm (larvae) 25-30 mm
Habitat Rivers & Streams Farmland
Diet Omnivores Root Feeders
Regions Eastern North America Western Europe, Central Europe, Northern Europe
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.

Cockchafer

A large, clumsy-flying chafer beetle that emerges en masse on warm May evenings. Its white C-shaped larvae are familiar agricultural pests across Europe.

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Did You Know?

In medieval Europe, cockchafer swarms were so destructive that they were once put on trial in court.