Every 17 years, in mid Atlantic states, the US sees the emergence of periodical cicadas — in very large numbers (we are talking trillions of these critters). Those large numbers ensure their survival, as they overwhelm their predators to the point of satiation: they just cannot eat all of them before they reproduce.
Speaking of which… their sole purpose is to find a mate and reproduce before they die . The larvae will go underground, where they will “live” for 17 years, feeding on the sap of trees, before the cycle starts all over again.
As the cicadas emerge, they go through quite the transformation. The nymphs burrow out of holes in the ground and head straight for tree trunks or tall grass blades or flower stalks. Once settled, they shed their nymphal skin and the adults first appear white with red eyes and shriveled wings.
They have a remarkable ability to shed their first skin and leave it almost intact, in a ghost-like vestige. The bottom of trees — their favorite place to climb — can be littered with hundreds of discarded shells.
As the cicada completes the adult transformation, it will have a black body, red eyes, and orange tinged wings.
Competition is fierce to find a mate and spaces are crowded.
Only the male cicadas sing: they gather in trees and bushes to form “chorusing” centers, which attract females. Females are silent and alert the male that they have heard his call by flicking their wings during the male’s call. These calls multiplied by millions of critters can be deafening!
What purpose do they serve? They are actually quite beneficial to the ecology (unless you’ve just planted new trees…). Their egg-laying in trees is a natural pruning that benefits the trees in succeeding years. Their emergence from the ground turns over large amounts of soil, and after they die, their decaying bodies contribute nitrogen and other nutrients to the soil.
Periodical cicadas are the “bugs of history.” First recorded by the 2nd Governor of Plymouth Colony in 1633, he wrote: “And the spring before especially all the month of May, there was such a quantify of a great sort of flies like for bigness to wasps or bumblebees, which came out of holes in the ground and replenished all the woods, and ate the green things, and made such a constant yelling noise as made all the woods ring of them, and ready to deaf the hearer.”