INJURY TO CROPS BY INSECT PESTS 3 



Grasshoppers of various species are also always more or less 

 injurious and often become a serious menace. Probably the most 

 serious injury, however, is done by subterranean larvae such as 

 the cut-worms, wireworms, white grubs, and webworms, which 

 breed in sod land, and by the hordes of little leaf -hoppers which 

 are always prevalent, but whose injury often passes unnoticed. 

 Ten per cent of the hay crop was worth $150,000,000 in 1919 and 

 this is a fair estimate of the damage done to hay and forage crops 

 by their insect enemies. 



Cotton. The cotton plant has a number of injurious insect 

 enemies, of which the boll weevil, bollworm, and leafworm are 

 the most injurious. In 1904 the writer made a statistical study 

 of the decrease in the cotton crop of Texas due to the boll 

 weevil, and showed that it was then costing that state $25,000,000 

 per annum.* This estimate has been confirmed by' independent 

 investigations made by Mr. W. D. Hunter of the U. S. Bureau 

 of Entomology, and although the loss in Texas is not so serious 

 at present, the weevil has spread eastward as far as Georgia, so 

 that its total injury remains practically the same, and has 

 undoubtedly been a large factor in the higher price of cotton 

 in recent years. The bollworm is most injurious in the south- 

 western cotton-producing States, where it causes a loss from 

 5 to 60 per cent of the crop. The total damage to cotton by 

 the bollworm is approximately $100,000,000 per annum and not 

 infrequently exceeds that amount. In 1880 the United States 

 Entomological Commission made an investigation of the cotton 

 worm and valued its ravages at $30,000,000, but with the 

 extensive use of Paris green and arsenical poisons its injury has 

 been greatly reduced and now amounts to from $5,000,000 to 

 $20,000,000 annually. Various minor pests of the cotton plant 

 inflict a considerable amount of local injury and with the above 

 pests damage the crop at least 10 per cent, worth $160,000,000 

 in 1919. 



Tobacco. Tobacco is attacked by insects, which form one 

 of the chief " bugbears " of tobacco growing, at all stages of its 

 existence. Ten per cent of the crop, worth $35,000,000, is cer- 

 tainly destroyed by them every year. 



* E. D. Sanderson, The Boll Weevil and the Cotton Crop of Texas. (Bul- 

 letin Dept. of Agriculture, Insurance, Statistics and History, Austin, Texas, 

 1905, p. 28, 7 maps.) 



