10 EXTERMINATING THE TEXAS-FEVER TICK. 
size. In a few days the young tick changes from a brown color to 
white (fig. 4, @), and in from five to twelve days sheds its skin. The 
new form has eight legs instead of six, and is known as a nymph 
(fig. 4, b, and fig. 5). 
In from five to eleven days after the first molt the tick again 
sheds its skin and becomes sexually mature. It is at this stage that 
males and females are with certainty distinguishable for the first 
time. The male (fig. 6) emerges from his skin as a brown, oval tick, 
about one-tenth of an inch in length. He has reached his growth 
and goes through no further development. He later shows great 
activity, moving about more or less over the skin of the host. The 
female (fig. 7) at the time of molting is slightly larger than the male. 
She never shows much activity, seldom moving far from her original 
point of attachment. She still has to undergo most of her growth. 
After mating the female increases very rapidly in size, and in from 
twenty-one to sixty-six days after attaching to a host as a seed tick 
she becomes fully engorged (fig. 1) and drops to the pasture, to repeat 
the cycle of development. 
SUMMARY OF LIFE HISTORY. 
To sum up, on the pasture there are found three stages of the 
tick—the engorged female, the egg, and the larva; and on the host 
are found four stages—the larva, the nymph, the sexually mature 
adult of both sexes, and the engorged condition of the female. 
METHODS OF ERADICATION. 
In undertaking measures for eradicating the tick it is evident that 
the pest may be attacked in two locations, namely, on the pasture 
and on the cattle. 
In freeing pastures the method followed may be either a direct or 
an indirect one. The former consists in excluding all cattle, horses, 
and mules from pastures until all the ticks have died from starvation. 
The latter consists in permitting the cattle and other animals to con- 
tinue on the infested pasture and treating them at regular intervals 
with oils or other agents destructive to ticks and thus preventing 
engorged females from dropping and reinfesting the pasture. The 
larve on the pasture, or those which hatch from eggs laid by females 
already there, will all eventually meet death. Such of these as get 
upon the cattle from time to time will be destroyed by the treat- 
ment, while those which fail to find a host will die in the pasture 
from starvation. 
Animals may be freed of ticks in two ways. They may be treated 
with an agent that will destroy all the ticks present, or they may be 
rotated at proper intervals on tick-free fields until all the ticks have 
dropped. 
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