THE CORN ROOT- APHIS ^ AND METHODS OF 

 CONTROLLING IT. 



THE CORN EOOT-APHIS commits serious depredations on 

 growing corn each year. It is very generally distributed 

 throughout the United States east of the Rocky Mountains, but it 

 is an especially destructive pest in the " corn belt " from Ohio to 

 Iowa and Nebraska, including southern Wisconsin, Its abundance 

 and destructiveness in these regions may be 

 traced with reasonable certainty to the prac- 

 tice of growing two or more successive crops 

 of corn on the same land, and this fact has 

 a direct bearing on the practical control of 

 the insect. It is injurious also to cotton in 

 the South Atlantic States and to cultivated 

 asters almost everywhere, 



THE CORN ROOT-APHIS AND ITS INJURY. /? V :^f. 



The corn root-aphis (fig. 1) is a small, fig. i. — The corn root- 

 soft-bodied insect not larger than a pin- aphis : wingless fenmie of 



, f . '- the form that produces 



head, almost spherical when full grown, living young, oreatiyen- 

 and of a bluish-green color, more or less iff*^-, ^Redrawn from 



° ' . Forbes.) 



dusted with a fine whitish powder which 



makes it appear grayish-green. The aphids cluster on the corn roots 

 (fig. 2) and suck the plant juices, this continual drain acting on the 

 plant in somewhat the same way as a drought. The greatest and 

 most noticeable injury occurs in spring before the plants have 

 made any considerable growth. Infested plants are dwarfed and 



Aphis maidiradicis Forbes. 



3 



