Forest Preserve District of Cook County, Illinois
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Mr. Big Noise -- The Cicada
Nature Bulletin No. 457-A   May 13, 1972
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

MR. BIG NOISE -- THE CICADA


Youngsters who visit our forest preserves will always remember next summer of 1973 -- just as old residents remember 1939 and 1922 -- because Brood XIV of the Periodical Cicada, commonly called the "17- year locust" will appear again next year. About this time next year, depending on the weather, the nymphs will begin to come out of the ground and climb onto trees, bushes, tall weeds or even posts and poles, where they transform into adults.

As many as 40,000 may emerge from beneath a single big tree. During April, when planting shrubs in wooded areas, we turned up two or three of those nymphs with every spadeful of earth. In June of 1973 there will be millions and millions of cicadas flying about and crawling on trees and shrubs. An adult lives only 5 or 6 weeks and by the end of July they all will be dead but their offspring will return in 1990.

It is very unpleasant to have one of these big insects blunder into your face or onto the back of your neck and some people, especially women and children, are terrified. Actually, a cicada is harmless. It looks fierce, like some kind of dragon, because of its broad head and big baleful red eyes, but it cannot bite nor can it sting.

They make an ungodly racket. The male has a very complicated sound- producing apparatus consisting principally of two drum-like membranes on the sides of his abdomen and strong muscles to set them in motion. His high-pitched "song" sounds like a buzz saw going through a log -- rising to a screech and then dying away -- but he keeps that up from dawn to dusk and has countless cousins doing the same. Sometimes they seem to synchronize so that the sounds rise and fall in waves that beat upon your ear drums; other times there is a weird monotonous whirring drone. It is nerve-wracking until you get used to it.

When a nymph has crawled up on a tree or other object it secures a good hold with the claws on its front legs. Presently its skin splits down the middle of the back and a soft white adult slowly works its way out. In a few hours it has hardened, darkened, and is fully mature with a stout brownish-black body about an inch long. The transparent wings have reddish margins and veins, with a black "W" near the end of each front wing.

Within a week the adults mate and the females begin to lay eggs. She has a dagger-like egg-laying apparatus with which she makes a series of slits on a tender twig of many kinds of trees and shrubs but generally on an oak, a wild crab or a fruit tree. In each slit she lays a dozen or more eggs. Moving from twig to twig, she lays a total of 400 to 600 eggs. In 6 to 7 weeks these hatch into ant-like nymphs which drop to the ground and burrow until each finds a tree rootlet, usually 18 inches or more beneath the surface. There it remains for 17 years sucking juice occasionally and going through six molts as it slowly grows.

That does not seem to hurt trees. Neither does the damage done to the twigs although, in most cases, they and their leaves die. Small, immature trees and fruit trees may be badly hurt but otherwise the injury is temporary. Valuable small trees may be protected with coverings such as cheese cloth but, in spite of new powerful insecticides, no sprays or dusts are really effective. They would have to be applied too often and come in direct contact with the cicada. Since the adult seldom feeds and then only by sucking plant juices.

What a life: 17 years underground and then a dumb wife !


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