This is the year of the cicada, or so says entomologists who study these things.
In 2004, the “17 year locusts” (known to entomologists as “Brood X”) are expected to be a problem in: Delaware, Georgia, Illinois, Indiana, Kentucky, Maryland, Michigan, North Carolina, New Jersey, New York, Ohio, Pennsylvania, Tennessee, Virginia, and West Virginia. Entomologists also predict that “Brood X” cicadas will be a problem in 2021 and 2038.
Cicadas are also known as “Periodical Cicadas” and “Locusts”. They are large (up to 1-1/2 inches long), dark insects, with transparent wings held over their bodies in a roof-like position. Perhaps they are best known for their noise, as the male cicadas have special vibratory organs that produce loud, strident sounds.
There are many species of cicadas in the United States. The periodical cicada (Magicicada septendecim), found only in the eastern United States, is the longest-lived insect in North America. The southern race has a 13-year life cycle; the northern race, called the 17-year locust, occurs every 17 years. The various broods (populations) are numbered, so their appearance can be accurately predicted. On the thirteenth or seventeenth spring as many as 40,000 cicadas may appear from beneath a single tree.
Damage
They emerge from the ground – where they have spent the past 17 years – when the soil temperature reaches about 64° F. They leave holes in the turf about a half-inch in diameter. From there, they immediately crawl up an object like a treee or a fence.
They break out of their exoskeletons and the adults emerge. This is where they do most of their damage. Females use their sawlike egg-laying organ to cut the bark and sapwood of twigs, causing the leaves on damaged twigs to turn brown. Damaged twigs may eventually break and fall to the ground.
Immature cicadas can also damage shrubs and trees by sucking sap from plant roots while the adult cicadas suck sap from young twigs.
Before the adults die, they mate and lay up to 600 eggs per female. After six to 10 weeks the eggs hatch and the nymphs fall to the ground, burrow, and start the 17-year cycle all over again.
Control
Mature cicadas can be controlled by applying insect killer when their singing is first heard and then repeat the application every 7 to 14 days, as necessary. Cut off and destroy injured twigs as soon as possible. Young trees can be protected with mosquito netting. Do not plant new trees in the spring when periodical cicada emergence is predicted.