SB 
818 
c578 R No. 91. Issued July 3, 1907. 
ENT ie es 
nited States Department of Agriculture, 
BUREAU OF ENTOMOLOGY. 
L. O. HOWARD, Entomologist and Chief of Bureau. 

NOTE ON THE OCCURRENCE OF THE NORTH AMERICAN FEVER TICK 
ON SHEEP. 
By W. D. HUNTER, 
In Charge of Cotton Boll Weevil Investigations. 
There are no published records of the finding of specimens of the 
North American fever tick (Boophilus annulatus Say) on sheep. In 
fact, it has generally been supposed that this species does not occur on 
sheep, although Mr. B. H. Ransom has surmised that such might be 
the case.! In connection with the tick work of the Bureau of Entomol- 
ogy an agent, Mr. J. D. Mitchell, has recently obtained data which 
indicate a rather general occurrence of the fever tick on sheep. On 
account of the considerable practical importance of this matter it is 
thought advisable to publish this preliminary note. 
The practical importance of the discovery made by Mr. Mitchell lies 
in the fact that the dissemination of ticks by sheep may play a very 
important part in the work of eradication that is now under way. In 
the general work of the eradication frequent use must be made of the 
* starvation’? plan under which the cattle are removed from pastures 
for a considerable time. In many parts of the tick-infested area most 
of the cattle raisers have as many cattle as they can possibly carry on 
their holdings. To be forced to dispense with the use of a part of the 
pasture area in many cases would force the sale of a portion of the cat- 
tle, perhaps at an unfavorable time for marketing. If, however, it were 
possible to allow some other kind of live stock to graze on pastures 
from which ticks are being eradicated according to the starvation plan, 
the inconvenience and possible loss to the ranchmen would be consider- 
ably lessened. Since the North American fever tick has previously not 
been known to infest sheep, it has been thought that the pastures might 
be used for grazing these animals. The discoveries made by Mr. 
Mitchell, however, indicate that the dissemination of fever ticks by 
sheep is of such practical importance that, at least in the parts of Texas 
where the matter has been investigated, a pasture would remain infested 
indefinitely even if the sheep alone were allowed to roam over it. It is 
not a case of the scattering of the seed ticks from one part of the pasture 



1Cir. 98, Bureau of Animal Industry, U. 8. Dept. Agric., p. 8, October, 1906. 
