SEVENTEEN-YEAR LOCUST, the Cicada septendecim. There is no insect known to science which affords such an interesting study as does the seventeen year locust. He begins and ends life in the bright sunshine, but spends 17 years in the dark, cold earth. Safely hidden from sight he gnaws away at the roots of trees, does his best to kill them, and then, emerging into the light, completes the death dealing operation by making as vicious an attack on the branches as was made on the roots. He is of a coal black color, marked with bright orange yellow, and there is a white spot on the head just behind the eyes. There are four glassy wings, and the eyes are red.
When the insect emerges from the ground after its 17 years' burial it works its body rapidly backward and forward like a man trying to put on an extremely tight coat. The result of the movement is the breaking of the shell and the imme diate appearance of its wings. It makes instantly for the nearest tree. The lo custs pair at once. They then congregate on the branches of the trees in sufficient numbers to bend and at times break them by their weight.
The females prepare the nest by clasp ing a branch of moderate size and per forating it with holes by means of an awl-shaped piercing instrument with which they are provided. They repeatedly thrust this piercer obliquely into the bark and wood in the direction of the fibers, at the same time putting in motion the lateral saws which detach little splinters of wood and make a fibrous lid over the whole. In each fissure made by the
piercer the female deposits from 10 to 20 eggs in pairs. It takes her a quarter of an hour to prepare one nest and fill it with eggs and she usually makes be tween 15 to 20 fissures in one limb. She lays between 400 and 500 eggs and then soon dies.
The perforations made in the limbs cause their death, and an orchard visited by seventeen-year locusts is ruined. Six weeks after the eggs are laid they hatch. The young when it bursts the shell is of a yellowish white color except the eyes and the fore claws, which are reddish. It is grublike in form and has six legs. On the shoulders, where 17 years later the wings appear, are little protuberances and directly under the breast is a long beak for suction. After being hatched the young locusts loosen their hold on the limb and fall to the earth. They in stantly dig their way into the ground where they seek out the tender roots of plants and trees. These they cut with their beaks and draw out the vegetable juices which constitute their sole nourish ment—and thus it is for 17 long years.
The drums of the male locust, on which they perform during their short lives above ground, are formed of convex pieces of parchment gathered into numerous fine plaits and are lodged in cavities behind the thorax. The insects play on these drums by the means of muscles which contract and relax with great rapidity.