12 AGRICULTURE 



corn roots, or to the roots of certain weeds after the corn 

 roots have become hard. The ants take this ^are of the 

 aphis because it gives out a sweet substance called "honey 

 dew," upon which the ants feed. The presence of many 

 ants in the corn-field, especially ant-holes in the hill, is 

 a sign of the root aphis. 



The worst damage by the aphis is done while the corn 

 is very young. The lice sometimes destroy the roots even 

 before the plant comes up. The effect of their work on the 

 corn roots causes the plant to turn yellow and take on a 

 sickly appearance. If they are very severe in their attack, 

 the tips of the leaves become purplish, and the stem reddish 

 in color. The yield of the crop is greatly reduced, and its 

 ripening delayed. 



Rotation of crops is one of the surest remedies against 

 this pest. Harrowing the field before the corn comes up, or 

 while it is small, interferes with the work of the ants, and 

 hence checks the ravages of the aphis. Keeping the fields 

 clean of weeds is also necessary, since the lice thrive on 

 the roots of such plants as smartweed and foxtail. 



Cutworms. Cutworms do little damage except on 

 sod land which has been in meadow or pasture for a num- 

 ber of years. They are a grayish-brown color, and grow 

 to an inch or more in length. Cutworms work at night, 

 cutting the young stalk of corn off just at the surface of 

 the ground. 



One remedy for cutworms is the fall plowing of sod, 

 thus exposing the insects to the freezing of winter. This 

 will greatly reduce their number. A shorter rotation of 

 crops, leaving the field in sod but one or two years, will also 

 tend to destroy the cutworms. 



Wireworms. Wireworms also make their home in 

 sod, and hence are worst in newly broken ground. They 



