Dog days and cicadas

July 1, 1993

The time of the year when late August fades into early September is sometimes referred to as the dog days of summer. This period is characterized by prolonged periods of heat and humidity, and many hear a constant buzzing in their ears when they venture outside. The irritating buzzing is not caused by the climatic conditions or a malady in your sense of hearing, but by so-called dog-days cicadas emerging from their underground incubators, and the males issuing their mating calls in hopes of attracting a member of the opposite sex.

The vibrations of a set of plates in a cavity of the abdomen produces the monotonous, irritating, droning sound that is only produced by the males. Perhaps the male cicada is lucky. The ancient philosopher Xerachos noted in his writings, “Happy is the cicada, since his wife has no voice.”

These insects are often incorrectly referred to as locusts, but that term should only be used for members of the grasshopper order of insects. Biologists believe the misnomer is a result of early settlers confusing the emergence of large numbers of cicadas with the biblical account of plagues of locusts in Egypt. Plagues of short-horned grasshoppers, or locusts, have occurred in the western United States from time to time, with perhaps the most famous being the hordes of these insects and the devastating affects they produced on the crops of the early Mormon settlers in Utah.

Dog-days cicadas spend about two years developing underground, with broods overlapping so that some emerge each year, whereas other types require a period of either 13 or 17 years of subterranean development and are called periodical cicadas.

The dog-days cicada is a chunky, cigar-butt shaped insect about 2 inches in length. It is blackish in color with green markings, and the wings are clear. It has a long, formidable looking beak that it uses to penetrate plant tissues. After mating, the female lays her eggs in slits on twigs of trees or shrubs made by her rapier-like ovipositor located on the rear end of her body. The male dies soon after mating, but the female may live for several weeks after she has deposited her eggs.

The eggs hatch in two or three weeks, and the young nymphs fall to the ground and quickly burrow under. The juveniles use their sharp, hollow beaks to feed on the rootlets of plants by sucking out the nutritious sap. If the ground becomes too cold, the nymphs go into a state of suspended animation. They continue development when the temperature of the soil warms to a desired degree. When the underground period of development is completed, the cicada digs its way to the surface and climbs up the stem of some nearby plant. It then sheds its outer covering and emerges as a sexually mature adult with fully functional wings.

I have known a few individuals who have a morbid fear of these insects and suffer from the psychological malady known as entomophobia (fear of insects). Cicadas do not bite, invade the household, or transmit diseases to animals. The adults, as do the nymphs, feed on plant sap with the aid of their piercing and sucking type of mouthparts. If an infestation of these insects is heavy, damage may be done to various plants, and homeowners and farmers are advised to protect young trees and nursery stock, especially fruit trees.

These rather large insects are readily devoured by insectivorous birds, and, believe it or not, may provide a source of nourishment for humans. Some years ago a friend of mine on the staff of the Field Museum of Natural History in Chicago was studying the development of a batch of periodical cicadas he had discovered in an area in northern Will County, about 30 miles south of Chicago. He invited me to go along on one of his field trips to the site where he unearthed large numbers of cicada nymphs to measure their developmental progress.

He told me not to bring a lunch to the field, saying he would provide. When lunchtime arrived, he produced a box of saltine crackers from his knapsack and proceeded to squeeze the contents of the bodies of the young cicadas onto the saltines. That was lunch! After a period of soul searching, I finally joined him in the repast.

The cicada pate on the crackers resembled a spread of homogenized avocados, and, surprisingly, was quite tasty. I doubt, however, if you will find canned cicada spread on a shelf in the gourmet section of the market, but its edibility is something for the outdoors person to keep in mind in case of an emergency. Bon appetite.

Dr. Robert Hedeen is a former resident of Maryland’s eastern shore and resided in the Chicago area from 1960-1971. He is a retired professor emeritus of biological sciences in the University of Maryland system. He has published more than 30 scientific papers, has written numerous magazine articles, and is the author of two books on the natural history of the Chesapeake Bay.

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