PLATE 84 
A. —Gall of Pemphigus populi-transversus, lips not protruding. 
B. —Gall of Pemphigus populi-transversus, lips protruding. 
C. —Gall of Pemphigus populi-ramulorum. 
D. —Beginning of gall of Pemphigus populicaulis . 
E. —Full-grown gall of Pemphigus populicaulis. 
All natural size. Drawn by Miriam A. Palmer. 
F. —Turnip seedlings, showing injury by Pemphigus populi-transversus: a, infested; 
6, control. Turnips were planted at Baton Rouge, La., on September 16, 1916, in 
boxes having cloth-covered tops. Galls of P. populi-transversus were placed in 
box a on September 28. Photographed on October 13, at which time the wingless 
form of the aphid was abundant on roots of plants in box a. No root aphids found 
in box b. Note difference in growth of plants in the two boxes. 
