Common Water Penny vs Hercules Moth

Side-by-side species comparison

Attribute Common Water Penny Hercules Moth
Scientific Name Psephenus herricki Coscinocera hercules
Order Coleoptera Lepidoptera
Family Psephenidae Saturniidae
Size 4-6 mm (adults); 6-10 mm (larvae) 270 mm wingspan
Habitat Rivers & Streams Forests
Diet Omnivores Omnivores
Regions Eastern North America Oceania
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.

Hercules Moth

Has the largest wing area of any moth — up to 300 square centimeters. Named after Hercules for its great size. Adults live only about two weeks and do not eat.

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Did You Know?

The Hercules moth has the largest wing surface area of any insect on Earth — its wings can cover an area larger than an open human hand.