Bulletin No. 16. New Series. 
U.S. DEPARTMENT OF AGRICULTURE; 
DIVISION- OF ENTOMB >LOGY. 
THE HESSIAN FLY IX THE 
UNITED STATES. 
I'EKTAKKD UNDER THK DIRECTION OF THE ENTOMOLOGIST, 
By HERBERT 0SBOBN, 
Prof e*8or of Zoology and Entomology, Iowa Agricultural College, Ame*, Toica. 
WASHINGTON: 
GOVERN mi«:n T pbikting office. 
1808. 
