56 INSECTS AND MAN 



markable feature about this remarkable insect is the extra- 

 ordinary duration of its immature stages. From the time 

 the larva emerges from the egg to the time the perfect insect 

 appears, no less a period than seventeen years elapses in 

 one race it is thirteen years. During the whole of this time 

 the very existence of the insect is unsuspected and unindi- 

 cated. No less remarkable is the regularity with which, at 

 the end of every generation, millions of individuals attain 

 maturity at practically the same moment. "Without 

 warning this cicada suddenly emerges over greater or 

 smaller areas, filling the ground from which it issues with 

 innumerable exit holes, swarming over trees and shrubs, 

 and making the air vibrate with its shrill, discordant notes. 

 During its short aerial life it leaves very decided marks 

 of its presence in the egg slits which thickly fill all the 

 smaller twigs and branches, the killing or injury of which 

 causes some temporary harm and a sort of general twig 

 pruning not especially injurious to forest trees, but more so 

 to fruit trees, and very undesirable and disastrous to young 

 trees and nursery stock." 



" Following briefly the history of the insect, the young 

 ant-like larva, hatching from the eggs a few weeks later, 

 escapes from the wounded limbs, falls lightly to the ground, 

 and quickly burrows out of sight, forming for itself a little 

 subterranean chamber or cell over some rootlet, where it 

 remains through winter and summer, buried from light, 

 air, and sun, and protected in a manner from cold and frost. 

 It lies in absolute solitude, separated from its fellows, in 

 its moist earthen chamber, rarely changing its position, save 

 as some accident to the nourishing rootlet may necessitate 

 its seeking another. In this manner it passes the seventeen 

 or thirteen years of its hypogeal existence in a dark cell 

 in slow growth and preparation for a few weeks only of 

 the society of its fellows and the enjoyment of the warmth 

 and brightness of the sun and the fragrant air of early 

 summer. During this brief period of aerial life it attends 



