190 ENTOMOLOGY. 



crop cultivated which the infesting insects do not diminish 

 by at least one-tenth — an amount of injury which would 

 hardly be noticed. They often injure crops to the extent 

 of one-fourth or one-half, and occasionally entirely destroy 

 them, as during the ravages of the wheat-midge in this 

 State in 1854-1857. One of our ex-Governors, in his agri- 

 cultural addresses, has frequently urged that insect-depre- 

 dations upon crops of one-fourth or one-half their value 

 should be regarded as a direct tax of twenty-five per cent 

 or fifty per cent levied upon their full value, and collected, 

 perhaps, year after year, without a show of resistance; but 

 which each farmer could, and therefore should, resist, and 

 thereby relieve himself from at least a portion of the bur- 

 den." 



The following estimates of the losses incurred by the 

 people of the United States will cause one to realize how 

 large a sum, much of which by proper care and foresight 

 could be saved, is annually wasted. The agricultural prod- 

 ucts of the United States are said to amount annually to 

 $2,500,000,000; of this amount we probably annually lose 

 by the attacks of insects not far from one-twentieth, or 

 $100,000,000. The losses from the ravages of the locust 

 in the border or Western States in 1874 were estimated at 

 $45,000,000; those occasioned by the chinch-bug in Illinois 

 in 1864 amounted to over $73,000,000, and in Missouri in 

 1874 to $19,000,000. The average annual loss to the cotton- 

 raising States from the cotton-worm from 1860 to 1874 was 

 estimated as about $15,000,000. 



While it is estimated that each species of plant on the 

 average supports three or four species of insects, very 

 many plants, especially those in general cultivation, afford 

 subsistence to many more; for many species which now 

 attack garden vegetables or fruits, before the settlement of 

 this country lived on plants of different species, but now 

 concentrate their attention on one. Thus the Colorado 

 potato-beetle in its native state lived on a species of Solanum; 

 and most if not all the other species now injurious to the 



