Indian Corn, or Maize 121 



are yellowish-green with twelve black spots on the back. The 

 mature insects feed on the silk and on the kernels at the tip of 

 the ears. Crop rotation helps to destroy them. The Northern 

 worms feed on no other roots than those of corn ; consequently 

 depriving the larvae of their food will starve them. The South- 

 ern worms feed on some other species of plants ; nevertheless 

 their principal food is corn roots and rotation is, therefore, a 

 benefit. Experience in the corn-belt shows that when a sys- 

 tem of crop rotation is practiced, little damage is done to the 

 corn by this insect, but when corn follows corn the damage is 

 likely to be excessive. 



Corn root-louse. Like all members of the plant-lice family, 

 the corn root-louse gets its nourishment by sucking sap from the 

 plants. The plant, deprived of some of its food, soon weakens 

 and, if the ravages are excessive, may die. The lice are smaller 

 than the head of a pin and are found in large numbers on corn 

 roots. There are from nine to twelve generations a year and, 

 as may be inferred, the damage done by such a large number 

 of insects is very great. Lice are always found associated with 

 ants which guard and care for them and in return for this 

 service the lice excrete through two tubes on the back of the 

 abdomen a sweet liquid known as honey-dew on which the 

 ants feed. The finding of ants near a hill of corn nearly always 

 means that lice are at work on the roots. The effect of the 

 insects is to retard growth and to produce a yellowing of the 

 corn. Often the tips of the leaves will have a purplish tinge 

 and the stalks a slightly reddish color. As the corn is retarded 

 in growth, it is likely to be caught by early frosts, the yield 

 will be poor, and the quality not of the best. When the corn 

 roots become woody, the ants transfer the lice to roots of smart- 

 weed and foxtail. Weedy fields are for this reason often badly 

 infested with the insect. The principal remedies are rotation 

 of crops and early and clean cultivation. Rotation of crops 

 deprives the lice of their food and the ants will take them away. 

 Clean cultivation destroys smart weed and foxtail and, if done 



