Anoplognathus porosus is about 25 mm long and creamy-gold with short, dark parallel grooves on the wing-covers. In the very similar Anoplognathus boisduvali the grooves on wing-covers are more conspicuous. Anoplognathus viriditarsis and Anoplognathus montanus are very similar to one another, about 25 mm long and bronze coloured with a green iridescent sheen.
Christmas beetle is a name commonly applied to Australian beetles belonging to the genus Anoplognathus because the adults emerge around Christmas time. Beetles in the northern parts of Australia tend to become active earlier in the year than those further to the south. Christmas beetles range from 15 - 40 mm in size and come in many colours. Most are golden brown, but they can be green or black. The 35 species of Anoplognathus belong to the subfamily Rutelinae in the Family Scarabaeidae .
Mostly active at night, Christmas beetles are often attracted to lights. Adult Christmas beetles feed on eucalypt leaves. Their larvae are white, crescent-shaped grubs with pale reddish brown heads that feed on roots in grasslands, lawns and pastures.
Farming and clearing in the past 200 years has changed the environment, creating a Christmas beetle population boom. Once only small areas of grassland existed. Now there are vast areas of grazing land, increasing the feeding grounds for beetle larvae.
Eucalypt forests, where the adult beetles feed, have decreased in size since European settlement. As a result the adult beetles often overgraze the eucalypts, with isolated trees particularly vulnerable.
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