140 



AI^ ECONOMIC ENTOMOLOGY. 



males, who alone are musical, giving rise to that oft-quoted old 

 saying,— 



" Happy the cicadas' lives, 

 For all have voiceless wives." 



The plan of the sound-organs can best be described by com- 

 paring to a slightly convex-bottomed tin pan, which makes a 



Fig. ioi. 



Fig. 102. 



e, Ceresa bubahis, ovipositing in slits b ; the 

 eggs, d, arranged as at c; old, scarred punc- 

 tures shown at e. 



The dog-day harvest-fly, 

 Cicada tibicen. 



snapping noise whenever the bottom is forced to change from 

 convex inwardly to convex outwardly. By an exceedingly rapid 

 snapping of the convex "drum" of the cicada, the continuous 

 shrilling sound is produced, intensified and modified by the vari- 

 ous tense membranes more or less surrounding it. 



The most famous species of this family is the "periodical 

 cicada," or " seventeen-year locust," Cicada septendecim. It is 

 of especial interest from the unusually long larval period, re- 

 maining in the Middle and Northern States sixteen years beneath 



