THE SEVENTEEN-YEAR LOCUST: ITS ENEMIES. 177 



tender branches of the trees were so wounded in the deposit of the eggs 

 that they broke from the main stems in the following year and fell to 

 the ground, thus completely denuding the trees of their fruit-bearing 

 branches " (Wm. G. Wayne, of Seneca Falls, N. Y., in lit.). 



These injuries to fruit trees are often quite serious, especially when they 

 are young. Almost every tree in young orchards has been known to 

 have been killed by them. Peach and pear trees suffer severely from 

 the punctures, and grapevmes have also been badly injured. 



The peach twigs sent from Canandaigua, in 1882, show unmistakably 

 the severity of the attack. Pupa-cases were adhering to them, for the 

 number emerging from the ground compelled their distribution not only 

 over the trunk and principal branches but even their extreme tips be- 

 fore they could find the necessary space to attach themselves for their 

 transformation. The fissures made in oviposition were very close — in 

 some instances running into one another as a continuous slit for the ex- 

 tent of two and three inches. One piece of twig, but twelve inches in 

 length, contained fifty-three of the fissures. 



The punctures made by the insect with its beak, for food, also con- 

 tributes to the death of the twigs. The female only is chargeable with 

 this injury, as her longer life and the development of her eggs renders 

 food essential to her. She has accordingly been provided with a com- 

 plete digestive apparatus, while her consort, destined to live for but a few 

 days, shows scarcely a trace of a digestive canal (Burnett, Proc. Bost. 

 Society Nat. Hist., iv, 185 1, p. 71). 



Natural Enemies and Checks. 



When we recall the immense numbers in which these broods at times 

 present themselves in their extension over hundreds of miles of terri- 

 tory, bending the branches beneath the weight of a half dozen or 

 more individuals upon each leaf (Burnett, loc. cit., p. 72), and endeavor 

 to form some conception of the fearfully augmented successive broods 

 that would result from an unchecked multiplication, we cannot but feel 

 a profound gratitude for the beneficent operation of the conservative 

 forces in nature, that effectually prevent such an undue increase. Of 

 the five hundred eggs borne by each female, as a rule but two eggs only 

 complete their cycle and develop into the perfect insect, to maintain 

 the number of the preceding brood. Fortunate it is that the insects 

 are exposed to so many casualties and to destruction from so many ene- 

 mies. Dr. Harris remarks; 



Their eggs are eaten by birds; the young, when they first issue from 

 the shell, are preyed upon by ants, which mount the trees to feed upon 

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