FARMERS BULLETIN 891. 



the leaves become brown or otherwise discolored. Although even 

 the heavily infested plants seldom are killed outright, usually they 

 do not make any appreciable growth. Infestations later in the sea- 

 son are less noticeable and indeed seldom are recognized because the 



Fig, 2. — Young corn plant showing corn root-aphids feeding on the roots. 



plants as a rule are not injured outwardly. The extent of apparent 

 damage varies with the season; conditions favoring the growth of 

 corn sometimes enable the plants to make a fair development in 

 spite of the insect, and an unfavorable season makes the injury un- 

 usually conspicuous. 



HOW TO RECOGNIZE ROOT-APHIS INJURY. 



Injury by the com root-aphis may be distinguished from that 

 caused by other insects if the following points are observed : (1) Boot 



