THE PERIODICAL CICADA 



downward and slanted toward the door. Generally there 

 are six or seven eggs in each row (E), making twenty-four 

 to twenty-eight eggs in the whole nest, but frequently 

 there are more than this. The wood fibers at the en- 

 trance are much frayed by the action of the ovipositor 

 and make a fan-shaped platform in front of the door 

 (A, B, C). Here the young shed their hatching garments 

 on emerging from the nest. The series of cuts in the bark 

 eventually run together into a continuous slit, the edges 

 of which shrink back so that the row of nests comes to have 

 the appearance of being made in a long groove. This 

 mutilation kills many twigs, especially those of oaks and 

 hickories, the former soon showing the attacks of the 

 insects by the dying leaves. The landscape of oak- 

 covered regions thus becomes spotted all over with red- 

 brown patches which often almost cover individual trees 

 from top to bottom. Other trees are not so much in- 

 jured directly, but the weakened twigs often break in the 

 wind and then hang down and die. 



An ovipositing female (Plate 7) finishes each egg nest 

 in about twenty-five minutes; that is, she digs it out and 

 fills it with eggs in this length of time, for each chamber 

 is filled as it is excavated. A female about to oviposit 

 alights on a twig, moves around to the under surface, 

 and selects a place that suits her. Then, elevating the 

 abdomen, she turns her ovipositor forward out of its 

 sheath and directs its tip perpendicularly against the bark. 

 As the point enters it goes backward, and when in at full 

 length the shaft slants at an angle of about forty-five 

 degrees. 



In a number of cases females were frightened away at 

 different stages of their work, and an examination of the 

 unfinished nests showed that each chamber is filled with 

 eggs as soon as it is excavated; that is, the insect com- 

 pletes one chamber first and fills it with eggs, then digs 

 out the other chamber which in turn receives its quota of 

 eggs, and the whole job is done. The female now moves 



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