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