Common Name – Whirligig Beetle

Phylum: Arthropoda

Class: Insecta

Order: Coleoptera

Family: Gyrinidae

Gyrinus natator, commonly known as the whirligig beetle, is a small aquatic beetle in the family Gyrinidae. Native to the Palearctic region, including much of Europe and parts of Asia, it is not naturally widespread in the United States. However, related species within the genus Gyrinus are found across North America, particularly in freshwater habitats like ponds, lakes, and slow-moving streams.

Ecologically, G. natator thrives in sunny, calm waters with sparse vegetation. It is highly gregarious, often seen in swirling groups on the water’s surface. This behavior, combined with its divided eyes—adapted to see both above and below water—helps it detect predators and prey simultaneously.

Biologically, the beetle is about 6 mm long, with a shiny black dorsal surface and reddish limbs. It is an adept swimmer and can also fly, allowing it to colonize temporary water bodies. Feeding primarily on small invertebrates like water fleas and insects that fall onto the water, it plays a role in controlling aquatic insect populations.

Mating occurs in summer. Eggs are laid on aquatic plants, and larvae, resembling centipedes, develop underwater before pupating on emergent vegetation. Adults overwinter submerged, clinging to underwater structures.