By day, the chorus chants the pulsating notes of survival and, by night, the musicians play their forewarning songs of autumn’s approach. Who are these perennial songsters that fill our environment with sounds of summer’s end?
The daytime chants belong to the cicada, a blackish stout-bodied, large transparent winged insect with a blunt head and green markings. The cicada’s sound production is one of the most complex processes of the insect world and it is more often heard than seen.
Generally, it is the male who sings by vibrating a pair of drums in its abdomen through powerful muscular action. Sounds can be modified by the cicada through its sounding boards. In ancient Greece, cicadas were kept in cages to hear them sing and the Greeks wrote poetry about them.
The various species of cicadas have similar life cycles with variation only in the length of their immature life underground. Eggs are laid on plant and leaf stems, hatch and fall to the ground.
The nymphs burrow into the earth and remain there four to 20 years (depending on species), sucking root juices and sap. In the North, the Periodical Cicada lives in the ground sap for 17 years.
When full grown, the nymph digs its way out of the ground with its enlarged front feet and climbs a tree. The skin splits, is shed and the mature adult emerges. Adults live long enough to mate and start another brood. Although the arboreal adults do not eat, they are eaten by many birds.
The evening entertainment of rhythmic song filling the warm night air is the love song of the male cricket to attract females. Songs are produced by rubbing wings that feature a thickened vein with tiny cross ridges - the file - and a sharp part along the edge of the wing - the scraper.
The scraper of either wing can be rubbed against the file of the other wing to produce the chirping sound. Even as winter approaches, the males continue to fiddle with good cheer until the cold kills the adults.
The silent female, after fertilization, uses her ovipositor to deposit eggs into the ground. In the wild, this act is performed in the fall and the small banana-shaped yellow or white eggs hatch the following spring.
An adult female can lay more than 2,400 eggs during her brief lifetime. When hatched, the nymph is the size of the egg and reaches maturity through a series of molts. Among the various species, our common black field cricket is about one inch long at adulthood. Crickets will eat anything from leaves to shoe leather to each other.
Traditionally, for thousands of years crickets were kept as pets in China and Japan and today, in many parts of the world, the cricket is still symbolized as a notion of good luck. Charles Dickens in his renowned tribute “The Cricket on the Hearth,” wrote “to have a cricket on the hearth is the luckiest thing in the world.”
Since no insect possesses a true voice, its sounds are entirely instrumental. In their present numbers, neither the cicadas nor the crickets pose an environmental problem locally. So savor those love sounds of fortune and forewarning, for new orchestras are being created for future generations to ponder upon and enjoy.