Habits, and Power for Injury. 99 



fond of congregating on fences, buildings, trees, or anything 

 removed from the moist ground. They also prefer to get 

 into such positions to undergo their different molts. In 

 fields they collect at night or during cold, damp weather, 

 under any rubbish that may be at hand, and may be enticed 

 under straw, hay, etc., scattered on the ground. Old prairie 

 grass affords good shelter, and where a wheat-field is 

 surrounded with unburnt prairie, they will gather for shelter 

 along the borders of this last. 



Their power for injury increases with their growth. At 

 first devouring the vegetation in particular fields and 

 patches in the vicinity of their birth-places, they gradually 

 widen the area of their devastation, until at last, if very 

 numerous, they devour every green thing over extensive 

 districts. Whenever they have thus devastated a country 

 they are forced to feed upon one another, and perish in 

 immense numbers from debility and starvation. Whenever 

 timber is accessible they collect in it, and after cleaning out 

 the underbrush, feed upon the dead leaves and bark. A 

 few succeed in climbing up into the rougher-barked trees, 

 where they feed upon the foliage, and it is amusing to see 

 with what avidity the famished individuals below scramble 

 for any fallen leaf that the more fortunate mounted ones 

 may chance to sever. This increase in destructiveness 

 continues until the bulk of the locusts have undergone 

 their larval molts and attained the pupa state. The pupa, 

 being brighter colored, with more orange than the larva, 

 the insects now look, as they congregate, like swarms of 

 bees. From this time on they begin to decrease in numbers, 

 though retaining their ravenous propensities. They die 

 rapidly from disease and from the attacks of natural enemies, 

 while a large number fall a prey, while in the helpless condi- 

 tion of molting, to the cannibalistic proclivities of their own 

 kind. Those that acquire wings rise in the air during 



