EXTERMINATING THE TEXAS-FEVER TICK. 
1a 
TIME REQUIRED TO KILL TICKS BY STARVATION. 
The time required for the ticks to die out after all animals have 
been removed from infested fields and pastures varies considerably, 
depending principally on climatic and weather conditions. 
The 
dates when pastures will be free of ticks, begimning during each 
month of the year, are given in the following table: 
Time required to free pastures from ticks by starvation. 
Date of removal of all animals 
from pasture. 
| Date when pas- 
| ture will be free 
from ticks. 
PIPTLOM DELGE ei i a coe cw ete ns vee 
October 1 to November 1, inclusive. 
March 1. 
May 1. 
July 1. 
August 1. 
Date of removal of all animals 
from pasture, 
Date when pas- 
ture will be free 
from ticks. 
| September 1. 
September 15. 
October 15. 
November 1. 
DOME OI an tetera coe amano August 15. 
The above table is based on investigations by Hunter and Hooker @ 
at Dallas, Tex., and by the writer at Auburn, Ala., under cooperation 
between the Bureau of Animal Industry and the veterinary depart- 
ment of the Alabama Polytechnic Institute. All the periods ob- 
tained by Newell and Dougherty (1906)° in work carried on at 
Baton Rouge, La., which is much farther south, are shorter. The 
above periods should be found ample for all localities lying no farther 
north than Dallas, Tex., or Auburn, Ala. The periods necessary to 
starve out an infestation for many localities in the southern part of 
the infested region are no doubt somewhat shorter than those given 
above. In general, moisture and cold prolong and dryness and heat 
shorten the duration of an infestation. If various portions of the 
same pasture differ with regard to temperature and moisture, as is 
frequently the case, some parts become free of ticks before others 
do. Other things being equal, high, dry, unshaded land becomes 
tick free sooner than low, damp, shady land. 
The simplest and safest plan in most cases, however, will be to 
follow the foregoing table in the region indicated for it. It is prob- 
able that the periods given in the table should be lengthened a little 
for the northern part of the infested region. The experiments con- 
ducted thus far in various places indicate this and it will place the 
eradication work in that region on the safe side. For example, E. C. 
Cotton’ obtained at Knoxville, Tenn., records for September and 
April somewhat longer than those given above. They are as follows: 
Cattle removed April 15; pasture free of ticks November 13. 
Cattle removed September 15; pasture free of ticks July 18. 
In localities with temperature and other conditions similar to those 
at Knoxville, Tenn., these periods should be followed. 
@ Bulletin 72, Bureau of Entomology, U. 8. Department of Agriculture. 
6 Circular 10, State Crop Pest Commission of Louisiana. 
¢ Bulletin 81, Agricultural Experiment Station of the University of Tennessee. 
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