Brown Bunyip - Tamasa tristigma
Brown Bunyip is one of the most commonly seen cicadae in Brisbane bushlands and gardens. They can also be found on casuarinas (she-oak), acacias (wattle) and jacarandas. They are medium size and usually sit on the tree trunks about two meters from the ground. They often sit in the shadow, together with their camouflaged colour, they are not easily be seen.
(Text Source: Brisbane Insects)
It is thought that the sound produced by some communal species can act as a defence against predatory birds and some are even loud enough (120 decibels) to be painful to the human ear. Cicadas also often sing in chorus, which makes it more difficult for a predator to locate an individual.
Cicadas are so conspicuous that many of their common names were initially given to them by children. As a result, cicadas probably have the most colourful common names in the insect world. Some of these include: Black Prince (Psaltoda plaga), Double Drummer, Floury Baker, and the Green Grocer or Yellow Monday, Cyclochila australasiae
Although only males produce the cicadas' distinctive sounds, both sexes have membranous structures called tympana by which they detect sounds, the equivalent of having ears. Males disable their tympana while calling, thereby preventing damage to their hearing; a necessity partly because some cicadas produce sounds up to 120 dB (SPL) which is among the loudest of all insect-produced sounds. The song is loud enough to cause permanent hearing loss in humans should the cicada be at "close range". In contrast, some small species have songs so high in pitch that they are inaudible to humans.
(Text source: Wikipedia)