12 INTRODUCTION 



will be of the greatest economic, educational, and ethical 

 value to the learners. 



Economic Zoology has lately proved itself worthy of the 

 consideration of every American citizen. The number of 

 injurious insects in the United States is large and increas- 

 ing. They often destroy one fourth or even a half, and 

 sometimes the entire crop of a whole section. The agri- 

 cultural products of our country amount annually to about 

 $3,000,000,000, while the loss of crops from the attacks of 

 insects is estimated at $100,000,000. In 1874 in the 

 Western states, the Rocky Mountain locust caused over 

 $40,000,000 of damage. The chinch bug (Fig. 116) in 

 Illinois, during the year 1864, destroyed $70,000,000 worth 

 of crops, and in Missouri ten years later was responsi- 

 ble for the loss of nearly $20,000,000 worth of produce. 

 The governor of Texas recently made an offer of $50,000 

 to any one who should discover a remedy for the ravages 

 of the cotton-boll weevil (Fig. 121) . The San Jose scale 

 (Fig. 107) destroys acres of valuable fruit orchards an- 

 nually. A much greater loss to crops would result yearly 

 were it not for the fact that men have learned by the study 

 of zoology how to control some of the insect pests, and also 

 how to secure the greatest benefits from birds and a large 

 class of insects naturally helpful to man. Ignorance con- 

 cerning the food of hawks and owls caused the Pennsyl- 

 vania legislators in 1885 to pass -a law resulting in a loss 

 to the state of $2,000,000. By becoming acquainted with 

 the habits of animals, man is able to have dominion over 

 them, and by wise legislation to make such laws in regard 

 to their destruction or preservation as will be to the best 

 interests of not only the present but future generations. 



