Cicadas need 95 degrees to make their music

Forget about the boys of summer. The -bugs- of summer have emerged from their long slumber. The strange, clicky cry of the cicada fills the air in many parts of Iowa. The inch-long insects are more plentiful than you’d imagine — one-and-a-half million per acre — about a ton’s worth. Entomologist John Oddland says “The concentration itself helps them to survive. These animals are helpless against predators, at least one by one. But what they achieve is predator satiation. There’s so many of them that the predators can’t eat them all.” Most cicadas only live five weeks, after spending nearly two decades maturing before emerging from their shells. Odland says the survival of cicada young may depend on their mother’s choice of the tree on which she lays her eggs, which take 17 years to mature. Odland says “Seventeen years is a long time in the life of a tree. Only a few generations of cicadas can use the same tree, so that evolution may select for those mothers who seek young trees that have a long lifespan that can nourish their young for the next 17 years. Those young trees are also most likely to be found along sunlit forest edges.” The serenade of the male cicada is perhaps the loudest sound produced by any insect. To properly sing, Odland says the male needs to have a body temperature of about 95 degrees. Odland says “It takes a lot of energy to make all that noise. The animal really has to warm up. A few males start singing, they set up what’s known as a ‘calling center,’ and it’s likely that other males join that calling center to increase the amount of noise, rather than call individually, when someone else has already started. So, they concentrate partly to make more noise and attract more females—same theory as a heavy metal band. The noise you hear is from the male cicada, searching for a mate, but the racket makes him an obvious target for predators. Females who survive the onslaught can lay up to 600 eggs each, assuring survival of the species.