Bui. 1 10, Bureau of Entomology, U. S. Dept. of Agriculture. 



Plate I. 



Fig. 1.— Wheat Field Totally Destroyed by the Spring Grain-Aphis (Toxoptera 



graminum). 



Contrast with uninjured portion of field shown in figure 2. (Original.) 



Fig. 2.— Circular Spot in Wheat Field where Growing Grain has been Destroyed 



by the Spring Grain-Aphis. 



The growing grain on these circular areas is as completely destroyed as in the field shown in figure 1. 

 Increasing in size and number, the spots come to include whole fields. (Original.) 



