FAMILY APHIDID.^ 123 



Spring Grain Aphis.— The spring grain aphis or "green 

 bug" (Toxoptem graminum) has attracted a great deal of 

 attention, especially in the Southwestern wheat growing 

 sections; in Texas, Oklahoma, and Kansas where it has 

 caused severe injury to the wheat crop. It is an introduced 

 species and seems especially adapted to the Southern wheat 

 districts. It is extensively preyed upon by a small parasite 



Fig. 77. — The spring grain aphis {T oxopter a graminum) : winged migrant, 

 much enlarged; above, antenna of same highly magnified. (After Pergande, 

 Div. Ent.. U. S. Dept. Ag.) 



(Lysiphebus) , and this parasite assists in a large degree in 

 keeping it in check. 



Corn-leaf Aphis. — The corn-leaf aphis {Aphis maidis) is 

 injurious to the corn plant and occasionally appears in 

 destructive numbers but ordinarily is less injurious than the 

 related corn-root aphis. 



Corn-root Aphis {Aphis maidi-radicis) . — The corn-root 

 aphis is a special pest of cornfields and a larger part of its 

 attack is confined to this crop. It is a light green or bluish- 



