CHAPTER YI. 



LOCUSTS AND GRASSHOPPERS (acridiid.e) — Continued. 



Locusts. 



Only a few of the various kinds of grasshoppers 

 belonging to this family Acridiidai — of which nearly two 

 thousand species are known — can be correctly denomi- 

 nated locusts. A locust is a species of grasshopper that 

 occasionally becomes very destructive, and that moves 

 about in swarms to seek fresh food. Some Acridiidae 

 greatly increase in numbers locally, and become very 

 destructive — very often for one or two seasons only — 

 and still more rarely migrate from place to place, and 

 are then called locusts. The true migratory locusts are 

 species that have the migratory instinct or disposition 

 strongly developed, and that move over considerable 

 distances in swarms, and inflict serious injuries. Of 

 these there are but few species — less than a dozen, in 

 fact — although we hear of their swarms in many parts 

 of the world. 



