After spending nearly two decades living in underground tunnels sucking sap from the roots of trees and shrubs, millions of cicadas emerged from the ground in May and June.

In their few weeks above ground, periodical cicadas mate, lay their eggs, and then die.

Although they have a unique appearance-adult cicadas are one and one-half to two inches long and black with orange or orange-brown body stripes and red eyes and legs-the periodical cicada is best known for its incessant high-pitched droning, a sound many find annoying or even unbearable.

The males of the species are the culprits. Females are voiceless. Morning to night, the males produce five different mating sounds, the most common one sounding like "farro." Another common noise produced by the insects is a whirring sound.

Although the females don't make any noise, they make their mark with the damage they inflict on twigs and small branches. The female cicadas make egg-laying slits or punctures on branches and twigs. Twigs with a multitude of slits are often broken or partially broken from the branches.

More than 250 species of trees and shrubs are subject to attack by the egg-laying female. However, she seems to prefer oak, maple, apple, dogwood, and nut trees. Lone fruit trees or seedlings less than a foot tall are most vulnerable. Mature forest trees usually can withstand this temporary harm because the cicada finds many twigs in forests in which to deposit eggs.

If cicadas have damaged your trees, prune them. Cut out, as far as is practical, the badly-damaged twigs and branches. With fertilization, you can stimulate these trees to a rapid, vigorous growth so that the wounded places will heal more rapidly.

Cicada Facts and Fantasy

• The North American periodical cicada is not a locust. The Pilgrims dubbed the cicada a "locust" when it first appeared to them at Plymouth, Massachusetts, in 1634. The insect undoubtedly reminded them of the migratory locust, a species of grasshopper that ruined crops in Egypt in Biblical times and still is a threat to crops in many parts of the world.
• Stories about the sting of the cicada are false-the insect has no stinger. People sometimes mistake the vibrations of the wings or the sharpness of the feet as a sting. Likewise, it is a myth that fruit is poisoned if "stung" by a cicada.
• The dark bars on the cicada's filmy wings resemble a "W." To the superstitious, their appearance suggests that war is imminent.