Insects - The Singing Cicadas

The cicada has a fascinating life cycle, but most of us only become aware of these insects in summer when they reach adulthood and begin their drone-like call. Not all cicadas have simple, loud calls - some, like the Golden Emperor, have complicated songs. The summertime call of the cicada is made by the adult male to attract females (like frogs do). Their eggs are laid in scratches cut through tree bark, although there are some exceptions to this. Once breeding has been completed, the adults die.

When the eggs hatch, the larvae drop to the ground and burrow under the soil. The larvae attach themselves to tree roots and feed on the sap - this stage in their life cycle is called a 'nymph' stage. They spend as little as several months for some species or as long as several years for other species buried under ground, periodically shedding their skin as they grow.

When they have reached maturity, the cicada nymphs emerge from the soil as a group and climb onto a vertical surface. They shed their skin for the last time to become adult cicadas with their characteristic heavily-veined, transparent wings. Their empty nymph skin is commonly seen attached to trees and fence posts during summer and it is a diagnostic feature for cicada species identification. A few days after emerging from the soil, the males call for a mate and the cycle begins again.

The endemic Golden Emperor (Anapsaltoda pulchra) is one of Australia's biggest and prettiest cicadas. It only occurs in dense rainforests in a small area of the Wet Tropics extending from the southern Atherton Tablelands to the Kirrama Range northwest of Cardwell. The Nandroya Falls track in the Palmerston section of Wooroonoran National Park is a good place to hear the Golden Emperor but only for a few weeks in January.

This particular cicada's call is very distinctive, starting with two notes and then raising pitch and intensity before it suddenly drops down to a machine-like whirr. The Golden Emperor calls in groups but getting to see one up close is very difficult as they fly away when approached. Also, as their breeding season progresses, they gradually move higher up the tree trunks, making their call the only sign they are still around. The Golden Emperor is a delight just to listen to if you can't catch a fleeting glimpse of the fascinating insect itself!