Insects on the Farm 



161 



arsenic compound by sprays. When they eat the leaves, 

 they consume enough of the poison to induce their 

 death. Paris green, London purple, and arsenate of lead 

 are the most usual poisons. Grasshoppers, potato bugs 

 and army worms may be killed in this way. In some por- 

 tions of Texas there are leaf-cutting ants, which attack 

 and cut and carry off nearly all the leaves. These 



Fig. 99. Squash bug. A, eggs on leaf; 6, egg-shell; c, d, e, /, nymphs; g, adult. 

 After Chittenden. Bureau of Entomology, U. S. Department of Agriculture. 



ants do not eat the leaves, but carry them into their 

 underground nests and use them as a medium or soil 

 on which to grow a fungus which they do eat. These 

 ants are real "farmer insects," in that the food they eat 

 is grown by their own efforts. Carbon bisulfide, poured 

 into their nest, may sometimes destroy the colony, 

 (c) By Sucking the Juices. We may distinguish 



