Part 3

A few days after the periodical cicadas appear, their incessant drumming, or singing, is heard. Only the males have sound-producing apparatus, which consists of two shell-like inflated drums on the sides of the abdomen. Two strong muscles set the drums in motion.

The chorus begins at dawn. As the temperature rises, the volume swells. Throughout the day a blanket of sound rests over the countryside. In the evening the sound ceases.

When heard from a distance, the cicada chorus is a whirring, droning monotone. But if attention is concentrated on an individual insect, several notes can be distinguished. The loudest is represented by the syllables "tsh-ee-EEEE-e-ou." It is sustained 15 to 20 seconds. The middle portion is loud and shrill.

Another note is represented by "AH-O-oo." It has a mournful quality, and terminates abruptly in a lowered pitch. It is usually sustained about 3 seconds, and is repeated at intervals of 2 to 5 seconds.

Other notes consist of prolonged burring, which is the basic sound of the cicada, and soft, short purrs.

To begin a note, the cicada lifts its abdomen (the back part of the body) to a rigid, horizontal position. When the sound ends, the abdomen drops back to the usual, somewhat sagging position.

Damage to Trees

The egg-laying habits of the female cicada, which have been described, can cause severe damage or even destruction to young, transplanted trees in nurseries and orchards, and some damage to older trees.

Egg punctures can cause the twigs and branches of small, immature trees to wilt; and the wounds can give ingress to disease and serve as shelters and feeding locations for scale insects, woolly aphids, and other insects.

Twigs in which many egg pockets are made are often broken or partly broken from the tree. Sonic fruit is lost from bearing trees that have been severely injured.

Seventy or eighty species of trees, shrubs, and herbaceous plants harbor the eggs of the cicada. Those for which the female seems to have a preference are oak, hickory, apple, peach, pear, and grape.

Cicadas cause no visible feeding damage to plants and trees.

Reducing the Damage

The insecticides Sevin and TEPP are effective against the cicada, Sevin being preferred when residue restrictions do not prevent its use because of its much greater residual effectiveness. Use Sevin to protect ornamental plants, shade trees, and some fruit trees (apples, pears, peaches, plums, prunes, and cherries), and grapes, for which a tolerance has been approved. Otherwise, use TEPP.

=CAUTION.=--Sevin and TEPP are poisonous. Read and follow all precautions on the label. TEPP is extremely dangerous to handle. Serious illness, or even death, may result if it is swallowed, inhaled, or absorbed through the skin.

Sevin has long residual value against the cicada. One application applied when egg-laying begins will afford protection for 1 to 3 weeks, depending on the degree of infestation. Repeat applications only after reinfestation is evident. To prepare a Sevin spray, mix 2 pounds of a 50-percent wettable powder with 100 gallons of water.

TEPP acts only on direct contact with the insect. It does not affect insects that come to the tree after the spray has dried, thus orchards close to woodlands have to be sprayed almost daily. Orchards further from heavy infestations can be protected reasonably well by three or four applications a week apart. TEPP is most effective if applied early in the day, before the cicadas become active. Prepare a TEPP spray by mixing one-half pint of a 20-percent concentrate, or one-fourth pint of a 40-percent concentrate, with 100 gallons of water.

Orchard trees 1 or 2 years old may be protected by covering them with open-weave cloth, such as heavy cheese-cloth, netting, tobacco shade cloth, or the cloth used to cover tobacco seed-beds in the South. The cloth should be put in place as the cicadas begin to appear and should remain until, about 5 weeks later, most of them are gone.

Many growers refrain from planting orchards in a cicada year, or in the preceding year. Before postponing the planting of trees, they should consider cloth protection. The cost may be less than the loss represented by 1 or 2 years of delay in the development of a new orchard.

If little or no pruning is done to large trees the winter preceding an infestation, much of the injured wood can be pruned away the following winter.

In residential areas where the cicadas have previously been abundant, it is advisable not to plant young shrubs or trees around the home the year another emergence is expected.

Natural Enemies

Birds destroy many cicadas. Where cicadas are numerous and birds rather few, as in dense woods, cicadas are not materially reduced. Where the situation is reversed, as in small, open groves, or near houses, cicadas may be greatly reduced by birds.

Insects and mites attack cicada eggs, and a fungus disease kills some adults.

Prepared by Entomology Research Division, Agricultural Research Service

Washington, D.C.

Issued May 1953 Slightly revised May 1960

U.S. GOVERNMENT PRINTING OFFICE: 1960