Cicadas sound like a high-pitched buzz saw

By Al Lowe
Contributor

The noise which this insect makes is like a tiny, high-pitched buzz saw. It starts slowly, runs at high speed for a while, and then runs down. The originator of this strange sound is the Cicada. It looks like a great big fly but it isn't.
The body is short and thick. Cicadas in northern Ontario would be about two or three centimeters long. In the southern U.S. some would go up to about five centimeters, and there are tropical ones whose overall length is about eight centimeters. That's about three inches. Quite an insect!
Cicadas make their sounds in a very unique way. At the back of the thorax (the centre part of an insect's body) are two special plates. Under each of these is a cavity. The cavity has a membrane at one end, and a reflecting surface at the other. A ribbed structure, called a tymbal, starts the sound. The cavity, the 'drum', amplifies the sound a great deal. The drum of the Cicada is the most complex sound organ in the insect world.
The sound itself is by far the loudest produced by any insect. Some tropical cicadas produce sounds which are painful to the human ear.
Eggs are laid in the summer or fall, and they hatch very quickly. The little Cicadas, called nymphs, fall to the ground, burrow deep in the earth, and stay there for 17 years. That's right. This insect lives for 17 years.
In the 17th year, the nymphs burrow their way to the surface, shed their nymph skins, and become adults. They are adults for a month or two, long enough to mate and lay eggs. Only the male sings, and that's to attract the female Cicdadas.
I have never heard of plagues of Cicadas in Ontario, but they surely do occur further south. One of the worst cycles is 'Brood 10.' This occurred in 1919, 1936, 1953, 1970 and 1987. To give you an idea of numbers, 40,000 Cicadas were counted under one peach tree in Georgia.
Not all Cicadas have such long life cycles as this one. There are two, three, five and thirteen ones. There are more than 75 different species of Cicada in North America. One is called the dog-day locust' to remind us of those sweltering days in August.
The Cicada is called by many names, "Harvest Fly", "Periodical Locust", "Seventeen Year Locust", and so on. All of these names are wrong. It is neither a fly nor a locust, but what is called a 'true bug.'
The sound of the Cicada, Magicicada septendecim, is the sound of late summer. Forgive him for his noise - he has been waiting seventeen years for his big chance!