Whirligig Beetles

Gyrinidae

Classification

Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Order: Coleoptera
Suborder: Adephaga
Family: Gyrinidae

Pronunciation

How to pronounce Gyrinidae: /dʒɪˈrɪnɪdiː/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Dineutus discolor 2 by Grey T. Gustafson and Kelly B. Miller. Used under a CC BY-SA 4.0 license.

Dineutus emarginatus UMFS 3 by Fredlyfish4. Used under a CC BY-SA 4.0 license.

Dineutus carolinus UMFS 1 by Fredlyfish4. Used under a CC BY-SA 4.0 license.

Dineutus ciliatus by Grey T. Gustafson and Kelly B. Miller. Used under a CC BY-SA 4.0 license.

Dineutus emarginatus UMFS 4 by Fredlyfish4. Used under a CC BY-SA 4.0 license.

Dineutus carolinus UMFS 3 by Fredlyfish4. Used under a CC BY-SA 4.0 license.

Summary

Gyrinidae, commonly known as whirligig beetles, are water beetles renowned for their rapid swimming and unique adaptations, including divided eyes and specialized leg structures that aid in swimming. They are social insects that prefer calm waters and are active predators, contributing to aquatic ecosystems.

Physical Characteristics

Whirligig beetles are flattened and rounded in cross section, with a shape similar to an ellipsoid. They have divided compound eyes, short and plump antennae, and natatory hind legs that are flattened and fringed with bristles. Their integument is steely grey or bronze, finely sculpted, hard and elastic, producing a waxy outer layer.

Identification Tips

Look for the divided eyes which allow them to see above and below the water. Their gregarious swimming behavior is also a key characteristic. They are typically found swimming on the water surface and are colored steely grey or bronze.

Habitat

Whirligig beetles prefer areas of calm, flowing water with moderate current, such as streams, where they can feed on floating detritus and small insects.

Distribution

Approximately 700 extant species globally, with around 60 species in 4 genera in the local area.

Diet

Active predators that feed on small aquatic animals and drifting detritus.

Life Cycle

Adults carry a bubble of air under their elytra which allows them to stay submerged; they lay eggs underwater attached to water plants, and the larvae are predatory and benthic.

Reproduction

Eggs are laid in rows underwater on aquatic plants; larvae resemble those of other predatory beetles.

Predators

Birds and fish are known predators of adult whirligig beetles.

Ecosystem Role

Serve as both predators and prey within aquatic ecosystems, contributing to the balance of food webs in their habitats.

Evolution

Thought to be the earliest diverging lineage of the Adephaga based on molecular evidence, adapting to an aquatic lifestyle independently from other members of the group.

Similar Taxa

Dytiscidae (diving beetles)

Misconceptions

Often confused with other aquatic beetles; distinct for their unique swimming behavior and divided eyes.