Cicadas are typical of summer sounds along the East Coast of Australia. At the moment there is one singing rather loudly in a bottlebrush tree just off my back balcony. I read on Wilipedia this morning that the singing is a mating call. Well, there are plenty of others to answer him as the noise is horrendous at the moment. The others are a touch quieter & seem to be in the gum tree in my neighbour's yard. I have heard that they do not sing in the rain, and only if the temperature is above 28C. I find this interesting, but cannot seem to find anything to back this info up.
A few eeks ago I overheard a conversation of an older couple in a park, and the male made the comment as to how he does not hear the cicadas any more, and how they seem to have disappeared. Maybe he has a hearing problem, or has forgotten what they sound like, because the cicadas are out every day, especially around this park , as it is surrounded by scrubland.
I tried to get a pic of the one in the bottle brush tree this morning, but he is very well camouflaged amongst the leaves. Instead, I have posted a pic of one that landed on the fly screen of our holiday unit a few years ago.