Cicadas do little if any injury while feeding on plants. Adults sometimes cause injury when they insert eggs into twigs, producing splintering wounds. Cicadas are the largest Colorado Insects in the order Homoptera, which includes other sap-sucking groups such as leafhoppers, aphids and spittlebugs. Twenty-six species occur in the state. Although abundant, cicadas are far more often heard than seen.
Males make a variety of sounds to attract females.
Most commonly heard are loud, often shrill, buzzing, sometimes with several individual Insects synchronizing their songs. Other cicadas make clicking noises. Despite their large size, cicadas cause little injury. They feed on roots but cause no detectable harm to the plants. The greatest injury occurs when large numbers of certain cicadas, such as the Putnam's cicada, insert eggs into stems of trees and shrubs.