482 



THE SMALL GRAINS 



ton) is present always, but only occasionally does very 

 much damage. 



528. The wheat straw-worms. Two species of wasp- 



FIQ. 152. Seedling winter wheat plant infested with the spring grain 

 louse or " green bug." 



like 4-winged flies are rather destructive to wheat, and 

 one other attacks barley. The habits of all are similar, 

 and result in similar injuries to the crop. They weaken 



