VALUE OF BIRDS TO MAN. 27 
~ 
THE INCREASE OF INSECT PESTS. 
Insects introduced from foreign lands found here a para- 
dise, in which to multiply, in the great areas planted year 
after year to the same crops. Having escaped their native 
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 native lands. 
Certain native 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 crops 
of the farmer, and became important pests. 
Such are the cutworms (Noctuide) ; their 
name is legion. Others, having been reached 
in their desert or mountain homes by the 
advance of civilization, left their natural food 
for the more succulent plants raised by man, 
and so spread over the country from farm pig. 14. chinch 
to farm. Such are the chinch bug and the ve a en- 
Colorado potato beetle, which, as civilization 
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 energies. 
