From Ohio History Central
For insects that people see every summer, the name cicada is often unfamiliar to Ohioans. Many people call these insects locusts. This is incorrect. Locusts are similar to grasshoppers. Unfortunately, cicadas were misclassified years ago, and the name seems to have stuck. Cicadas can be recognized by their characteristic shape and large size. However, it is the song of the cicada with which people are the most familiar. This loud buzzing sound is made only by males, and is produced by vibrating internal structures within their drum-like abdomen.
In Ohio, there are two common types of cicadas, the annual (Tibicen chloromera) - also known as dog-day cicadas - and the periodical cicada (Magicicada spp). Both have sucking mouth parts. Annual cicadas are mostly large, blackish insects with greenish markings and large, clear wings. They appear each year in July and August. Usually found in treetops, adult periodical cicadas will lay eggs on twigs of trees and shrubs. The ends of these twigs often die as a result. The eggs hatch in a month and the nymphs drop to the ground, where they quickly burrow into the soil. Periodical cicadas spend much of their life underground feeding on the juices of roots. When nymphs emerge from the ground, around April and May, they will attach themselves to trees and molt for the final time, becoming adults.
It is the hard shell, or exoskeleton, of the nymph that people commonly find in their yards and on sides of trees in the summer
The 3/4 - 2 inch long adult cicadas will live for a least a month. They rarely eat during this period because their main goal is to reproduce so that the life cycle continues, but may take moisture from plants.