HEXAPODA : HEMIPTEBA CLDADAS. 



327 



Cicada (Cicada septendecim, Linn.), often incorrectly 

 called the Seventeen-year Locust. It is believed that the 



FIG. 437. 



Seventeen-- ear Cicada, Cicada septendecim, Linn. 

 FIG. 438. 



Dog-day Harvest-fly, Cicada canictilaris, Harris. 



latter insect appears in the same locality only at intervals 

 of seventeen years, and hence its specific name. 



The Seventeen-year Cicadas come in swarms in the early part of 

 summer, and the forests then resound with their singing from morn- 

 ing till night. The females, in laying their eggs, select small 

 branches and clasp them with their legs, and then repeatedly thrust 

 their piercers obliquely into the bark and wood in the direction of the 

 fibres, and at the same time detaching little splinters of wood at one 

 end, which serve as a fibrous -cover to the perforations. After thus 

 forming a fissure, they deposit therein from ten to twenty eggs, which 

 are conveyed to their places by means of the grooved side-pieces of 

 the piercers. When one fissure is filled, another is made and filled, 



