248 



SCHOOL ENTOMOLOGY 



The Oat Aphis (6), has been discussed (page 304), as an 

 apple pest, but should be here noted, as it is widely distrib- 

 uted on wheat and oats. The wingless females congregate 

 in the axils of the leaves, around the crown, and on the upper 

 roots, injury seeming to be worse in winter, when they often 

 cause the plants to turn yellowish. In the South this species 



\ 



Flu. 173. "Green bugs" on oat 

 seedling enlarged. 



FIG. 174. Spring grain-aphis 

 (Toxoptera graminum). Adult 

 wingless female greatly enlarged. 

 (After S, J, Hunter.) 



continues to reproduce on small grains without having an 

 alternate sexual generation on the apple. 



The Spring Grain-aphis or Green Bug * (17), although 



widely distributed, has been seriously injurious only from 



Kansas southward, although damage has occurred in the 



Carolinas and Tennessee and elsewhere. The wingless 



* Toxoptera graminum Rond. 



