12 Farmers' B all e tin W57. 



method gonerally used. The pasture-rotiition method is not only 

 more complicuted but the necessary tick- free fields are seldom avail- 

 able. 



In freeing pastures the method followed may be either direct or 

 indirect. The direct method consists in excluding all cattle, horses, 

 and mules from pastures until' all the ticks have died from starva- 

 tion. This plan is seldom followed because the owner is usually not 

 willing to give up the use of his pasture even temporarily. The in- 

 direct plan consists in permitting the cattle and other animals to 

 continue on the infested pasture and treating them at regidar inter- 

 vals with agents destructive to ticks, thus preventing engorged 

 females from dropping and reinfesting the pasture. All the seed 

 ticks on the pasture, or those which hatch from eggs laid by females 

 already there, will die eventually. Those that get on the cattle from 

 time to time will be destroyed by the treatment, while those which 

 fail to find a li^st will starve to death in the joasture. 



DIPPING. 



Ticks upon cattle may be destroyed by using a tick-destroying 

 agent, such as arsenic. The dipping vat is the best and cheapest 

 means of applying the remedy. The great advantage of dipping 

 over spraying and applying remedies by hand lies in the fact that 

 thoroughness of the treatment is practically assured. 



PROCEDURE IN DIPPING. " 



When eradication is undertaken, all the cattle, and also the horses 

 and mules if they harbor ticks, are treated rogularl}' every two 

 weeks during the part of the year that the temperature is favorable 

 to treatment, until the ticks have disappeared. The purpose of the 

 treatment is to destroy all ticks that get on the animals before they 

 have had a chance to mature and drop, thus preventing them from 

 reinfesting the pasture, farm, or range. If the treatment used were 

 absolutely effective in destro,ying each and every tick on the animals 

 treated there would be no renewal of the infestation after the treat- 

 ment is begun. The cattle would act simply as collectors of ticks 

 Avhich would be destroyed regularly by the treatment applied every, 

 two weeks. It is probable, however, that in most instances, either be- 

 cause of the lack of efficiency of the dip or imperfect application, or 

 because of failure to dip all cattle systematically, some ticks escape 

 treatment and reproduce, thus prolonging the time that otherwise 

 would be reciuired for eradication. 



If ticks apparently disappear from the cattle after they have been 

 under treatment for some time, the dipping should not be discon- 

 tinued until a number of careful inspections show that the cattk' aii> 



