Members of this family are closely related to scarab beetles but can be distinguished from the later as they have one extra segment (11 in total) on their antennae, and the last 3 segments form a distinctive circular club. They are very stoutly built beetles and range in size from 8-30 millimetres in length. Most adults are reddish-brown to brown in colour, although a few may be black. The head and pronotum of male geotrupids is often adorned with prominent horns and as such members of this species are often called rhinoceros beetles.

Blackbolbus puncticollis

Not much is known of the biology of geotrupid beetles and it is thought in Australia most adults lay their eggs in burrows in the soil and provide their larvae with decaying organic matter, hypogean fungi or dung to feed on. Geotrupids are often attracted to lights at night and will often emit a hissing or chirping sound when disturbed. Both the larvae and adults are able to produce sound by rubbing parts of their body together.

Blackbolbus puncticollis (profile)

Blackbolbus puncticollis lay their eggs in burrows in clay or sandy soils and provision the larvae with fungi and/or decaying organic matter. The burrows of this species are quite distinctive as the entrance is marked by a push up of dirt which, when fresh is ropey in appearance. If you find a burrow similar to this with the dirt still fresh and no visible opening, the beetle is definitely inside. Blackbolbus puncticollis occurs across Victoria, South Australia and Western Australia. It is a nocturnal species that is often collected from lights at night. Blackbolbus puncticollis is able to make a chirping/grating sound by rubbing their abdomen against a file on the hind leg.

For more geotrupid beetle species visit the Australian Insect Common Names - Geotrupidae section found here.



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