C

ICADAS Nothing symbolizes the heat of high summer like the long, lazy drawn-out call of the cicada. The loud buzzy sound starts slowly, but soon increases to a rousing crescendo before fading away again. Only male cicadas call. The sound often induces other males to join in, resulting in a whole chorus buzzing away. Naturally, the idea is to attract females, so the more cicadas, the louder the sound and the farther it travels. The distinctive sound of cicadas originates in a very different way from that of similar sounding insects, such as crickets and grasshoppers. The last segment of a cicada's thorax contains two hollow cavities, each covered with a membrane that acts like a drum. Muscles attached to these membranes cause them to vibrate. Most of the adult cicada's large abdomen is empty — a large hollow chamber that may help amplify the sounds produced in the thorax. Did you know... Cicadas belong to the family Cicadidae in the order Homoptera, or "bugs." The 17-year locust is really a cicada. In eastern North America there are 75 species of cicadas, each with a distinct call that helps it distinguish its own species and find a mate. Each species also sings at its own time of day and in its own particular habitat. Because different species sing at different hours, in some tropical countries local people say they can tell the time from the sound of the cicadas. Life cycle of the cicada After female cicadas have mated, they lay eggs in tree twigs by making a slit in the young wood and depositing the eggs inside. When the eggs hatch, the nymphs fall to the ground and immediately dig down into the tree roots, where they feed on sap. Here in their underground burrows, the nymphs remain for anywhere from 2 to 20 years (depending on the species and, possibly, the food supply) until they are ready to emerge one evening. If you are lucky enough to find a shed skin, you might also see an emergence hole, about 5/8" in diameter, in hard-packed earth near the base of a tree. Source for this material: A Guide to Observing Insect Lives by Donald Stokes This page was revised on 29 August 2001. © Fletcher Wildlife Garden Our e-mail address