1 EXTERMINATING THE TEXAS-FEVER TICK. 
TIME REQUIRED TO RENDER CATTLE FREE OF TICKS WHEN 
PLACED ON UNINFESTED FIELDS. 
Before discussing plans for rendering farms tick-free, involving the 
use of the information given in the foregoing table, it will be neces- 
sary to indicate how animals may be entirely freed from ticks by 
placing them on uninfested fields. This is based on the fact that the 
female tick must drop from the host to the ground before eggs can 
be laid and before young ticks will develop. 
The shortest time in which seed ticks will appear after engorged 
females have been dropped is twenty days. Consequently cattle 
placed on a tick-free field during the warmer part of the year are 
not in danger of becoming infested again with young ticks until 
twenty days have elapsed. The time required for all the ticks to 
drop after cattle have been placed on uninfested land varies with 
the temperature. It is much longer during the winter than during 
the summer. The time required, beginning at various times of the 
year, Is given in the following table: 
Time required for all ticks to drop from cattle placed on tick-free land. 
: All ticks will - 5 All ticks will 
When ticky cattle are placed on = When ticky cattle are placed on = 
tick-free land during— hay Sereue? | tick-free land during— Hay pa ed 
ANIGUSE tae sk eee ee ee Six weeks. Marchi:257. a. cce- sca= aceene settee Seven weeks. 
September. soc Sasa ies eee seas 0. DTI) eos Sen Seen eee ..-.-| Six weeks. 
Octobers ss = scan: Se Geecae auc Eight weeks. IM@Yes 2.5)25e pods Ket oe eee ee Do. 
Novemiberss¢e 522.2 cieeen-aeeeene Nine weeks. JUNG: aes bee eel cease seme Do. 
VANUATY te ee ieee eee oe ee Ten weeks. JY ete cee ose eae eee ee amb eee Five weeks. 
MeDruary : 2 25 ise) Saeco ces Seven weeks. 
FREEING CATTLE OF TICKS BY ROTATION ON TICK-FREE LAND. 
The plan of freeing cattle of ticks by rotating them from one iot 
or field to another is as follows: Beginning at any time of the year 
from February to September, inclusive, the cattle are removed from 
the tick-infested pasture they have been occupying to a tick-free lot 
or field, and continued there for not more than twenty days. During 
this time a considerable number of ticks will drop. In order to pre- 
vent the cattle from becoming reinfested (by seed ticks resulting 
from eggs laid by females that have dropped), the herd is then 
changed to a second tick-free inclosure for twenty days longer, and 
if they are not free of ticks by that time they are placed in a third 
tick-free inclosure for twenty days more. Should the two changes 
at intervals of twenty days have been made, sixty days will have 
elapsed, which is ample time for all ticks to have dropped during the 
portion of the year indicated, and the animals are ready to be placed 
on a tick-free pasture or field without danger of becoming reinfested. 
The periods to free cattle (given in the above table) are believed to 
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