BUGS. 
33 
extreme southern portions of the Mississippi Valley. 
The best way to check the increase of chinch-bugs 
is to burn the weeds and grasses surrounding the 
grain fields. This destroys vast numbers of eggs. 
The chinch-bug has at times been the cause of the 
destruction of three-fourths of the grain crop in some 
of our Western States; but it was killed off by an 
epidemic which swept off millions of them. Moist, 
cool, cloudy weather is very bad for their health. 
THE CICADA AND THE HARVEST-FLY. 
This is in many respects the most interesting 
species of this family. Its periodical occurrence 
once in about seventeen years, the damage it does 
vegetation by laying its eggs upon it, and its won¬ 
derful vocal apparatus, make it one of the most in¬ 
teresting of insects for study. 
The cicada is often called a locust, probably be¬ 
cause of the vast numbers in which it appears. It 
is not a locust and differs materially from the locust 
in several particulars. 
i. The head is broad and thin, beak very strong 
and sharp, eyes large and prominent, three ocelli. 
