VALUE OF BIRDS TO MAN. 27 



THE INCREASE OF INSECT PESTS. 



Insects introduced from foreign lands found here a para- 

 dise, in wliicli to multiply, in the great areas planted year 

 after year to tlie same crops. Haying escaped their natiye 

 enemies, they had come to an abundance of food in a land 

 where many of the insect-eating birds and other insectivo- 

 rous animals had been much reduced in number by the unwise 

 policy of the settlers. Hence the rate of increase of im- 

 ported insect pests in America has far exceeded that of the 

 same insects in their natiye lands. 



Certain natiye American insects, finding their food plants 

 destroyed by the cutting down of the forests or the break- 

 ing up of the prairie, turned their attention to the cr()})s 

 of the farmer, and became important pests. 

 Such are the cutworms (Noctuidee) ; their 

 name is legion. Others, haying been reached 

 in their desert or mountain homes by the 

 advance of ciyilization, left their natural food 

 for the more succulent plants raised by man, 

 and so spread oyer the country fi'om farm pj^ i4._chin<h 

 to farm. Such are the chinch bug and the iJ»J?' ""icii en. 



..... larged. 



Colorado potato beetle, which, as ciyilization 

 advanced westward, met it and spread toward the east. 



The enormous losses which have occurred in the United 

 States from the destruction of growing crops by insects must 

 seem incredible to those who do not realize how vast are the 

 numbers of insects, how stupendous their power of multi- 

 plication, how insatiable their voracity. 



When we fully appreciate the consuming powers of insects, 

 they assume an economic importance greater than can be 

 accorded to the ravening beast of prey. Let us consider 

 briefly, then, the potency for evil that lies hidden in the tiny 

 but innumerable eggs of injurious insects, which require only 

 the warmth of the summer sun to release from confinement 

 their destructive enersfies. 



