CHAPTER IV 

 INSECTS INJURIOUS TO VEGETATION 



Extent of Injury. - - People who live in towns and cities oc- 

 casionally hear of the destruction to crops caused by such in- 

 sects as the army worm and chinch bug, and notice the fact that 

 the leaves of trees are sometimes eaten away by beetles and cater- 

 pillars. Most of them do not realize, however, that every kind 

 of crop raised by the farmer, every kind of fruit tree cultivated 

 by the fruit grower, and every sort of forest and shade tree is 

 constantly being attacked by destructive insects and their value 

 considerably lessened on this account. We suffer financially 

 because the smaller crops cause higher prices, and when we learn 

 that about 10 per cent of every crop is destroyed by insects, we 

 can estimate in a general way how much we spend annually in 

 feeding these voracious creatures. The average annual damage 

 done by insects to crops in the United States was conservatively 

 estimated by Walsh and Riley to be $ 300,000,000 or about 

 $ 50 for each farm. A recent estimate by experts puts the 

 yearly loss from forest insect depredations at not less than 

 $ 100,000,000. The common schools of the country cost in 1902 

 the sum of $235,000,000, and all higher institutions of learning 

 cost less than $ 50,000,000, making the total cost of education 

 in the United States considerably less than the farmers' loss from 

 insect ravages. It costs the American farmer more to feed his 

 insect foes than it does to educate his children. 



Furthermore, the yearly losses from insect ravages aggregate 

 nearly twice as much as it costs to maintain our army and navy, 

 more than twice the loss by fire, twice the capital invested in 



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