Bui. 111, Bureau of Entomology, U. S. Dept. of Agriculture. 



Plate I. 



Fig. 1.— Nymphs and Winged Forms of the Hop Aphis (Phorodon humuli) on Hop 



Leaves. (Original.) 



Fig. 2.— Winter Eggs of the Hop Aphis. Position Indicated by Arrows. (Original.) 



STAGES OF THE HOP APHIS. 



