Diving Beetle

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Diving Beetle - Alan Henderson (Minibeast Wildlife)

Onychohydrus scutellaris

Streamlined body up to 34 mm in length, usually dark and glossy. Paddle-like hind legs with swimming hairs.

Details
Type
Invertebrate
Group
Animals
Insect - Beetle
Former Scientific Name
Homeodytes scutellaris
Biology

Immediately after biting their prey the adults secrete digestive enzymes into their prey. Diving beetles store air in a bubble held beneath their hardened wings. They use this oxygen during their underwater dives so they can hunt food and find mates. When prey numbers get too low, the beetles fly to a new water body and settle there. Adults lay their eggs in the water where tiny predatory larvae hatch out. The larvae spend their entire larval stage in the water before digging into the muddy banks and pupating.
Distinctive Markings

Large, paddle-like hind legs with a dense line of swimming hairs.
Taxonomy
Phylum
Arthropoda
Class
Insecta
Order
Coleoptera
Family
Dytiscidae
Genus
Onychohydrus
Species
scutellaris
Found throughout Australia, including across Victoria.

Source: Atlas of Living Australia

The adults are strong swimmers and use their hind legs together like boat oars.

Interesting Facts
Diet

Carnivore. Eats small aquatic animals including insects, crustaceans, worms, leeches, molluscs, tadpoles and possibly small fish.
Habitat

Lives in freshwater bodies such as dams and lakes.
Native Status
Native to Australia