It's summer again. Cicadas are emerging and the males are beginning to sing as the temperature rises. Temperature not only determines the onset of singing behaviour, but can even influence the colour of adult cicadas.
Many people on the east coast of Australia have grown up collecting the colourful cicadas known as Green Grocers, Yellow Mondays, Chocolate Soldiers, Blue Moons and Masked Devils. But how many people realise that these are all different colour forms of the same species, Cyclochila australasiae?
This widespread endemic species can be found in shades of green, yellow, dark tan and blue. The most common - green - colour pigment is known as insectoverdin, and is made up of yellow and blue mixed together. Sometimes either the blue or the yellow colour is absent, making yellow or (rarely) blue individuals. However, in regions where the climate is cooler, a black pigment is produced, creating a cicada with striking black markings on a green/yellow background. This is the form spreta – commonly known as the Masked Devil. It is believed that lower temperatures during the development of the cicada nymphs induce this colour variation.
Masked Devils have recently been seen (and heard) in great numbers in the Southern Highlands and Blue Mountains regions of New South Wales. One enquirer from Bundanoon sent in a photo of a Masked Devil seen in Morton National Park.
Moulds, M.S. 1990. Australian Cicadas. New South Wales University Press.
Cicadas
The Cicadas fact sheet provides information about Australian cicada identification, habits, singing and lifecycles.
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