SB 
818 
C578 
ENT 
No. 115. Issued April 15, 1910. 
_Aited States Department of Agriculture, 
BUREAU OF ENTOMOLOGY. 
L. 0. HOWARD, Entomologist and Chief of Bureau. 
THE HORN FLY. 
(Hematobia serrata Rob.-Desv.) 
By C. L. Martart, M.S., 
Assistant Entomologist and Acting Chief in Absence of Chief. 
INTRODUCTION AND SPREAD. 
The horn fly is one of the worst of the European biting flies that 
attack cattle, but, curiously enough, it failed to reach this continent 
until a comparatively late date, notwithstanding abundant impor- 
tations of live stock from Europe during nearly three centuries. It 
FIG. 1.—Horn fly (Hzmatobia serrata): a, Egg; b, larva; c, puparium; d, adultin resting position. Much 
enlarged. (From Riley and Howard.) 
was first discovered and reported to this Bureau in the fall of 1887 
as occurring near Camden, N. J. The following year it appeared in 
Maryland and Virginia, and thereafter spread rather rapidly, and 
by 1891-1892 it was found over the continent from Canada to Texas 
19566—Cir. 115—10 ansonian lnstitug™ 
