Whats that buzzing in my ear?
By Robert A. Hedeen, Naturalist
Many people in the Rock River Valley have recently experienced a monotonous, irritating, buzzing sound that follows them around when they step out of doors. If you are one that has been so afflicted, take heart! There is nothing physiologically wrong with your hearing apparatus, and you most certainly do not have an earwig roaming about in your auditory canal. The cause of the irritating cacophony is countless male cicadas sending forth their mating calls in hopes of attracting a member of the opposite sex.
These are the so-called dog-days cicadas that emerge about the first of August after a two-year underground incubation period. Sometimes these insects are incorrectly called locusts, but that term should only be used for members of the grasshopper order of insects. Some cicada species require a period of either 10 or 17 years of development underground and are termed periodical cicadas. Entomologists blame the misnomer on early settlers who confused the periodical emergence of cicadas with the biblical, periodical plagues of locusts appearing in Egypt.
The dog-days cicada is a cigar-butt shaped insect up to two inches in length. It is blackish in color with green markings, and the wings are clear. The cicada has piercing and sucking, needlelike mouthparts, but is not known to use its formidable beak on animals.
Only the male cicada is capable of producing the irritating (to humans, but not to other cicadas) mating call. Perhaps he is lucky in one respect, as the ancient philosopher Xerarchos wrote, Happy is the cicada, since his wife has no voice.
After mating, the female lays her eggs in slits on twigs of trees or shrubs made by her rapier-like ovipositor located on the posterior end of her body. The male dies a short time after performing his biological duty, but the female may live on for several weeks after laying her eggs.
In two or three weeks, the eggs hatch and the young nymphs fall to the ground into which they quickly burrow. With the aid of their sharp beaks, the juveniles feed on rootlets of plants by sucking out the nutritious sap. If the weather becomes too cold, they go into a state of suspended development before continuing to grow when the temperature of the soil warms. When the underground period of development is completed, the young cicada digs its way to the surface and climbs up the stem of some plant. There it sheds it body covering for the last time and emerges as a sexually mature adult with fully functional wings.
A few individuals have a morbid fear of cicadas which may develop into the psychological malady known as entomophobia (fear of insects). But, as a matter of fact, they do not bite, transmit diseases, or invade the household. As adults, cicadas pierce the relatively soft bark of young trees with their sucking mouthparts and feed on the sap. If the infestation is heavy, damage may be done, and homeowners and farmers should be advised to protect young trees and nursery stock, especially fruit trees.
And, believe it or not, these obnoxious insects are good to eat. Some years ago a friend of mine on the professional staff of the Field Museum of Natural History in Chicago was studying the development of a group of cicadas he had discovered underground in an area in northern Will County, some 35 miles south of Chicago. I accompanied my friend on one of his many trips to the area where he unearthed large numbers of cicada nymphs to measure their developmental progress.
He had told me not to bring a lunch to the field, saying he would provide. When noon arrived, he produced a box of 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 cicadas on crackers resembled a spread of homogenized avocados and, I must admit, were quite tasty. However, I dont think fresh or canned cicada spread will soon be a common item in the gourmet section of the supermarket.
By the end of September, the cicadas in our area will have disappeared, and peace and quiet will prevail until next August.
Dr. Robert Hedeen is a former resident of eastern Maryland, with degrees in zoology and botany. He is a former professor of biological science. He has had 30 scientific papers published, has written numerous magazine articles, and is the author of two books on marine biology of Maryland.