TEXAS FEVER, 487 



METHODS OF ERADICATING THE TICKS.^ 



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 agents destructive to ticks and thus preventing engorged females 

 from dropping and reinfesting the pasture. The larvae on the pas- 

 ture, 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 treatment, while those 

 which fail to find a host will starve in the pasture. 



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. The method most generally used is dipping the cattle in 

 a solution of arsenic. The pasture-rotation method is not only more 

 complicated, but the necessary tick-free fields are seldom available. 



The dipping vat is the best and cheapest means of applying the 

 tick-destroying solution. The great advantage of dipping over 

 spraying and applying remedies by hand lies in the fact that thor- 

 oughness of the treatment is practically assured. 



A^Tien eradication is undertaken, all the cattle, and also the horses 

 and mules if they harbor ticks, are treated regularly 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 destroying 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 

 which 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 



^ Only a general outline of methods of eradication will be given here. For detailed 

 information, including directions for the construction of dipping vats and for the prep- 

 aration of dips, the reader is referred to Farmers' Bulletin 1057, which may be obtained 

 free upon application to the Department of Agriculture, Washington, D. C. 



