THE ECONOMIC VALUE OF BIRDS 



his crops, one of the items which he must take into 

 consideration is the 2^ per cent, of his products 

 which goes to feed the insects of the surrounding 

 country. 



Not all insects are detrimental to man's interests, 

 but as we have just seen the Government officially 

 states that many of them are tremendously destruc- 

 tive. Any one who has attempted to raise 

 apples, for example, has made the unpleasant ac- 

 quaintance of the codling moth and the curculio. 

 Every season the apple raisers of the United States 

 expend eight and one-quarter million dollars in spray- 

 ing, to discourage the activities of these pests. In 

 considering the troubles of the apple growers we 

 may go even farther and count the twelve million 

 dollars' worth of fruit spoiled by the insects despite 

 all the spraying which has taken place. Chinch bugs 

 destroy wheat to the value of twenty million dollars 

 a year, and the cotton-boll weevil costs the Southern 

 planters an equal amount. 



Plagues of Insects. — Every now and then we read 

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