LIFE HISTORY OF PEMPHIGUS POPULI-TRANSVERSUS 
By Thomas H. Jones 1 
Entomological Assistant , Truck-Crop Insect Investigations , Bureau of Entomology, 
United States Department of Agriculture 
with technical descriptions by C. P. Gillette, Collaborator , State Entomologist 
of Colorado 
INTRODUCTION 
The first collection in Louisiana of aphids belonging to the genus 
Pemphigus from the roots of plants of the family Cruciferae seems 
to have been made on November 19, 1914, by Mr. E. S. Tucker, for¬ 
merly Associate Entomologist of the Louisiana Experiment Stations. 
These specimens were taken from cabbage roots (. Brassica oleracea 
capitata) at Loranger, in Tangipahoa Parish. Shortly afterwards root 
aphids of the same genus were noted at Baton Rouge by the writer, 
and material for identification was submitted to specialists acquainted 
with the genus. As the stages sent were not recognized as belonging 
to any described species, and as there were apparently no published 
records of any species of Pemphigus occurring on crucifers in the United 
States, studies concerning the life history, habits, and economic impor¬ 
tance of the species were begun. 
After the writer had begun the investigation Maxson (<23 , p. 501) 2 
published an article on Pemphigus betae Doane in which he stated 
that— 
Lice of this genus have been repeatedly taken on turnips in the south. 
In a letter to the writer Mr. Maxson has given the additional infor¬ 
mation that— 
the specific instances referred to were brought to my attention by Mr. F. B. Paddock, 
State Entomologist of Texas, he having sent material to me for identification. 
1 The writer wishes not only to thank Dr. Gillette for his kindness in drawing up the descriptions and 
supervising the preparation of illustrations, but also for suggestions regarding the biological studies, and 
especially for the interest which he has taken in the work. Mr. J. J. Davis, of the Bureau of Entomology, 
and Mr. J. R. Parker, of the Montana Agricultural Experiment Station, also have shown much interest 
in these studies, and the writer desires to thank them for the aid they have given. Messrs. C. E. Smith 
and J. L. E. Lauderdale, while members of the Bureau of Entomology, rendered valuable assistance in 
the studies of the life history and habits of the species. 
2 Reference is made by number (italic) to “ Literature cited,” p. 592-593- 
( 577 ) 
Journal of Agricultural Research, 
Washington, D. C. 
Pk 
Vol. XIV, No. 13 
Sept. ®3, 1918 
Key No. K- 71 
