EXTERMINATING THE TEXAS-FEVER TICK. fj 
tion of live stock, by reason of its important bearing in maintaining 
and improving the fertility of the soil, would be of distinct benefit in 
increasing the yield of field crops. An incidental though important 
advantage of stock raising and dairying would be found in the dis- 
tribution of the farmer’s income throughout the year, enabling him 
to live on a cash basis. It can thus be seen that the benefits which 
would accrue to southern agriculture from the extermination of the 
cattle tick would be very great and far-reaching. 
LIFE HISTORY OF THE TICK. 
Before methods of eradication can be carried out intelligently and 
successfully, it is necessary to know the life history of the tick, and 
the influence of temperature, moisture, and other climatic conditions 
on the various stages of its existence. These matters will therefore 
be taken up first, it being understood that whenever the term ‘‘tick”’ 
or ‘‘cattle tick”’ is used, it refers to the one species or kind, Marga- 
ropus annulatus.* 
The usual host for this tick is the cow or ox. Frequently, however, 
horses, mules, deer, and sometimes even sheep serve as hosts. But 
none of these latter animals, with the possible exception of deer, are 
susceptible to tick fever, consequently they suffer from the tick as a 
simple parasite and not as a transmitter of disease, although they 
must be considered in plans for eradication. 
Only a part of the development of the tick takes place on the host; 
the rest of the development occurs on the pasture occupied by the 
host. : 
DEVELOPMENT ON THE GROUND. 
In tracing the life history of the cattle tick it will be convenient 
to begin with the large, plump, olive-green female tick (fig. 1), some- 
what more than half an inch in length, attached to the skin of the 
host. During the few preceding days she has increased enormously 
in size as a consequence of drawing a large supply of blood. 
When fully engorged she drops to the ground, and at once, espe- 
cially if the weather is warm, begins to search for a hiding place on 
moist earth beneath leaves or any other litter which may serve as 
a protection from the sun and numerous enemies. The female tick 
may be devoured by birds or destroyed by ants, or may perish as the 
result of unfavorable conditions, such as low temperature, absence 
or excess of moisture, and many other conditions; so that many 
which fall to the ground are destroyed before they lay eggs. 
@ The reader desiring fuiler information as to the life history of the cattle tick is 
referred to Bulletin 72 of the Bureau of Entomology, United States Department of 
Agriculture, which may be obtained from the Superintendent of Documents, Govern- 
ment Printing Office, Washington, D. C., for 15 cents. 
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