The incessant call of male cicadas from local trees verifies that we are experiencing hot, dry weather. They become silent on cool, wet days. These curious insects are considered to be the noisiest of all insects. It is said that this auditory production is painful to the ears of birds thereby acting as a defense mechanism.
For all the noise they make, cicadas are hard to locate in the tree tops. The empty nymphal shells they leave clinging upright to trees are evidence of their presence.
By the time a cicada begins to sing from the trees, it has lived a fascinating life. They begin as eggs laid in a slit or groove in the bark of a tree. In a few days the eggs hatch into wingless nymphs that fall to the ground and burrow in. They feed on the sap of various tree and plant roots on their journey into the earth where they live in a dark, almost airless environment.
They will remain underground anywhere from two to seventeen years before emerging. Those who emerge in two to eight years are known as non-periodical. Another group remain underground for thirteen to seventeen years and are known as periodical cicadas.
Periodical cicadas are synchronized developmentally, so they explode in numbers during the year of their emergence. In our area of Texas we do not have any periodical broods.
After nightfall in late spring and early summer the encased nymphs will surface. They will emerge from their shell which slits in the back. During this time cicadas are vulnerable to predation from birds, turtles and wasps.
Time is precious to the cicada. They will live only a few weeks, so it is urgent that the males sing to attract females. Male cicadas produce the call by vibrating skins over the sides of their body at a high rate of speed. Once mated, the females place their eggs on trees and the developmental process begins. The adult male and female cicadas are soon spent, leaving behind new eggs to continue their life cycle.