CHAPTER XXIII 



SOME SPECIAL INJURIOUS INSECTS 



233. Insects that Attack Cotton. There are several 

 species of insects that injure the cotton plant, such as 

 the cotton army or leaf-worm, cotton boll-worm, the 

 Mexican boll-weevil, and the cotton aphis. The leaf- 

 worm and boll-worm may be destroyed by spraying 

 or dusting with arsenical poisons. 



234. The Boll- Worm of cotton, damages cotton by 

 destroying the locks of the bolls. The same insect 

 damages the tips of more than 75 per cent of the ears 

 in the corn fields. The damage to corn ears is probably 

 fully 3 to 5 per cent of the crop. The pupse hibernate 

 in the ground through the fall and winter and do not 

 mature into moths until late in the spring. These facts 



suggest the advisability of early fall 

 plowing to expose the pupa to the 

 severe weather conditions of the 

 winter seasons, predacious insects 

 and birds. (What other reasons have 

 already been mentioned for early 

 plowing?) Advantage is taken of the 

 habit of the insect of attacking corn 

 and cowpeas in preference to cotton, 

 to protect the latter. "Trap rows" of 

 corn and cowpeas are planted near 

 the cotton to attract the moths. In 

 this way the damage to the cotton 

 is lessened. Corn is used, also, in pro- 

 (165) 



Fig. 104. Mexican Cotton- 

 boll weevil. (Enlarged 

 five times.) Howard, 

 United States Depart- 

 ment of Agriculture. 



