Scarab Beetles or Cockchafers or Dung Beetles



This beetle family is second only to the Curculionidae in the number of species it contains, with over 2000 species currently described in Australia. They are small to large beetles and range in size from 2-70 millimetres in length depending on the species. Scarab beetles are adapted for burrowing and have well developed tibiae on their forelegs for digging. Most adults are stoutly built and have a plate known as the 'clypeus', which hides their mandibles when viewed from above. Some species of scarabs have prominent horns on their head or pronotum, which in some species is used for fighting off competing males.

The larvae of scarabs are distinctly C-shaped and mostly feed on fresh or decaying vegetable matter. Some species feed on decaying animal matter or the dung of native or introduced animals. Adult scarabs mostly feed on leaves and some species such as the well known Christmas beetles can build to huge numbers, devouring almost all leaves on favoured eucalyptus trees. Some scarab species are also known to feed on the nectar of native blossoms.

Onitis alexis (bronze dung beetle)

Onitis alexis is often found around lights at night and is recognisable by its squarish appearance and metallic sheen. It is a medium sized beetle which grows to about 18 millimetres in length. Onitis alexis is a dung beetle, which was introduced from Africa to improve Australian pastures. It is now well established in Australia and can be found across most of the country. This species helps break down cattle dung because the native dung beetles only like to feed on the dung of Australian native animals. Adults are active at dawn and dusk and are usually attracted to the dung of cattle. When they locate a fresh dung pad, adults will land to feed on the liquids and construct burrows in the soil beneath the pads. These burrows are provisioned with the dung which is formed into balls and serves as food for their developing larvae. This burying action assist in the breakdown of large amounts of dung, which native dung beetles are mainly not adapted for.

Onthophagus pentacanthus

(five horned dung beetle)

Many scarab beetles have large horns on their heads which are often used to fight other male beetles. Onthophagus pentacanthus can grow to be approximately 18 millimetres in length and has quite prominent horns for its size. This species is a native dung beetle and is common throughout much of the Murray-Darling basin and further west in South Australia. Adults are nocturnal and are often attracted to lights at night. They can be found in bovine dung, such as cattle and oxen and can also be collected from pitfall traps baited with human dung. The larvae of Onthophagus pentacanthus are coprophagous, which means they feed on the dung of other animals. The adults construct burrows for their young and presumably provision them with the dung of marsupials which the developing larvae feed on.

Anoplognathus pallidicollis

Anoplognathus pallidicollis is commonly known as a Christmas beetle as they are usually seen around the summer months feeding on eucalyptus leaves. They are usually large beetles growing to a length of around 20 millimetres. Many other Anoplognathus species are brightly coloured and are often attracted to lights at night. Adult Christmas beetles feed on the leaves of Eucalyptus trees and can cause severe defoliation when favourable weather conditions promote feeding swarms. One of the most characteristic features of this group are their large tarsal claws which are movable and uneven in length, most likely enabling them to hang onto the thin leaves of eucalyptus trees.


The larvae of Christmas beetles live and develop in the soil where they eat decaying organic matter or plant roots. The larvae mostly feed on the roots of native grasses and other vegetation, but in agricultural and urban areas larvae also feed on the roots of pasture, crops and turf. The feeding activity of larvae causes plants to wither and turn yellow. The feeding activity of some Christmas beetle larvae are commonly the cause of the yellow and dead patches seen in suburban lawns. Towards the end of winter or in early spring the larvae move close to the soil surface to hollow out a chamber in which to pupate. Adults emerge several weeks later, often after rain has softened the soil allowing them dig their way out. Large numbers of Christmas beetles may emerge at the same time after spring thunderstorms have soften the ground. If conditions remain dry, the adult beetles are unable to burrow to the surface and may die in the soil. Similarly if springtime brings flooding, they will drown. After emerging, adults fly to the nearest food plant to feed and mate. The females will then return to the soil and lay their eggs to begin the cycle again.

Colpochila species

Colpochila species belong to the subfamily of Scarabaeidae called Melolonthinae, commonly known as chafers. The Melolonthinae are a large subfamily of beetles that range between 5 and 40 millimetres in length depending on the species. Most chafers are reddish-brown to black in colour although some may be bicoloured or have a metallic sheen. Most species are nocturnal and can be attracted in large numbers to lights at night during the summer months. Others are active both during the day and night. Most adult chafers are foliage or nectar feeders and in some years numbers of certain leaf eating species can build to plague proportions and completely defoliate native trees and shrubs. The larvae of chafers, commonly called white grubs are C-shaped and can be found in the soil where they feed on the roots of plants and other organic matter. Some species are considered pests as they cause serious damage to the roots of crops such as wheat, sugar cane, vegetables and pasture.

For more scarab beetle species visit the Australian Insect Common Names - Scarabaeidae section found here.




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