04/14/1996

Rare Concert Offered by the Animal Kingdom: 13-Year Periodical Cicadas to Emerge this Spring

AUBURN, Ala.- A rare symphony will be held this spring in the animal kingdom, one that occurs only every 13 years and one that offers a fascinating glimpse of nature's extraordinary cycles and habits.

That symphony will be presented by 13-year periodical cicadas, which will emerge and fill the woods where populations exist with song in late April or early May. "The event is remarkable and spectacular," said Lacy Hyche, associate professor of entomology at Auburn University who researches the life cycles and habits of a wide variety of tree insects.

"Periodical cicadas (Magicicada spp.) are native to the hardwood forests of the eastern states and many people call them locusts," he continued. The "locust" moniker was conferred by colonists in New England, who encountered the cicadas more than 350 years ago and mistook them for locusts. "The early colonists knew nothing of cicadas, but they did know stories of the 'hordes of locusts' of the Old World, and apparently applied the same name to this 'horde' of unknown insects in the New World. In entomological language, the term 'locust' properly refers only to grasshoppers. Nevertheless, the name has persisted and is still commonly applied to cicadas today."

Periodical cicada adults are distinctive in appearance. They have broad, black heads and red eyes. Their black bodies taper rearward, their legs are red and their wings are transparent with reddish-orange veins. Adults are 1 1/4 to 1 3/4 inches long.

Though common, or dog-day cicadas, are present every summer, the periodical cicadas emerge only every 13 or 17 years. Seventeen-year cicadas are generally found farther north in the United States, while the 13-year cicadas are primarily found in the South. Several individual broods occur in each group, and each brood is identified by a number. Habits and developmental patterns are similar for all broods, varying primarily only in length of life cycle (13 versus 17 years) and the year in which the adults emerge.

The periodical cicadas of Alabama are Brood XIX of the 13-year group. Another 13-year brood, XXIII, occurs in areas of Mississippi and western Tennessee, bordering Alabama. A population believed to be of this brood was reported in Tuscaloosa County in past years, and Hyche said this and other small, isolated populations of Brood XXIII may still exist in some northwestern areas of Alabama.

"Brood XIX, however, is Alabama's main, and perhaps today its only, brood of periodical cicadas," he continued. "The brood is well established, and populations are widely scattered over much of the northern three-fourths of the state."

Beginning about the last 10 days of April or first week of May, cicada nymphs (the growing stage) should emerge from the soil at night, molt and leave cast skins (empty, dry husks) clinging to tree trunks and understory plants. Shortly thereafter, "singing," a loud droning-buzzing sound, begins and is heard throughout the daylight hours. "Singing" is done by male cicadas (only males possess sound-producing structures) to attract females. It is the singing that alerts most people to the presence of cicadas.

Within a few days, mating and egg-laying begins. "The females possess a strong blade-like ovipositor (egg-laying organ) that they use to slit the bark and wood of hardwood trees. Within that slit, they lay double rows of eggs, from 24 to 28 eggs per oviposition site," said Hyche.

Singing and egg-laying continues for three or four weeks, through most of May; then the adults die. After about 6 1/2 weeks, by about the end of June, the eggs hatch and fledgling cicadas drop to the ground and go underground, where they will reside for the next 13 years feeding off roots in the soil.

These cicadas are not considered major plant pests, but they can damage trees and shrubs. Though they possess sucking-type beaks that the nymphs use to feed on roots, the adult cicadas feed very little, if at all. However, when they slit open the bark and wood of trees and shrubs to lay eggs, they can damage and sometimes kill twigs and stems.

Following this year's emergence, Brood XIX will not be seen or heard again until spring of 2011.

Hyche has recently published a bulletin on these cicadas through the Alabama Agricultural Experiment Station (AAES). To receive a free copy-- contact the Office of Research Information, 2 Comer Hall, Auburn, Alabama 36849; (334) 844-4877–ask for AAES Bull. 635, "Periodical Cicadas (‘The 13-Year Locusts') in Alabama."

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News from:

Office of Ag Communications & Marketing

Auburn University College of Agriculture
Alabama Agricultural Experiment Station
3 Comer Hall, Auburn University
Auburn, AL 36849
334-844-4877 (PHONE) 334-844-5892 (FAX)

Contact Jamie Creamer, 334-844-2783 or jcreamer@auburn.edu
Contact Katie Jackson, 334-844-5886 or smithcl@auburn.edu
Contact Lacy Hyche (334) 844-2555