20 



Farmers' Bulletin 1057. 



becoming infested again with young ticks until 20 days have elapsed. 

 The time required for all the ticks to drop after cattle have been 

 placed on uninfested land varies "with the temperature, being much 

 longer in winter than in summer. Beginning at various times of the 

 year, the time required is given in Table 2. 



Table 2. — Time required for all ticks to drop from cattle placed on tick-free land. 



When ticky cattle are placed on 

 tick-free land during — 



August 



September 

 October... 

 November. 

 January... 

 February . 



All ticks will 



have dropped 



in — 



When ticky cattle are placed on 

 tick-free laud daring — 



Sis weeks. 



Do. 

 Eight weeks. 

 Nine weeks. 

 Ten weeks. 

 Seven weeks. 



March 

 April. 

 Maiy.. 

 June . . 

 Julv... 



All ticks will 



have dropped 



in — 



Pev:n weeks. 

 Si.\ weeks. 



Do. 



Do. 

 Five weeks. 



Freeing cattle of ticks by rotation on tick-free land. — The plan of 

 freeing cattle of ticks by changing them from one lot or field to 

 another is as follows : Beginning at any time of the year from March 

 *;o September, inclusive, in the southern half of the infested area, the 

 cattle are removed from the tick-infest'^^d pasture they have been 

 occupying to a tick-free lot or field and left there for not more than 

 20 days. During that time a considerable number of ticks will drop. 

 In order to prevent the cattle from becoming reinfested (by seed 

 ticks resulting from eggs laid b}" females that have dropped), the 

 herd is then changed to a second tick-free inclosure for 20 days 

 longer, and if they are not free of ticks by that time, they are placed 

 in a third tick-free inclosure for 20 daj^s more. Should the two 

 changes at intervals of 20 days have been made, 60 days will have 

 elapsed, which, during the time of year indicated, is ample time for 

 all ticks to have dropped, 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 table above) are believed to 

 be ample. It is a wise precaution, however, to examine the cattle 

 carefully for ticks before placing them in the uninfested field they 

 are to occupy. 



From October to Febnuuy, inclusive, the time recpiircd for seed 

 ticks to appear after females have dropped is much longer than the 

 time necessary for all the ticks to drop from cattle. Consequently, if 

 it is desired, the herd maj' be left on the same field for the required 

 length of time without danger of. reinfestation. 



Table 3 gives the approximate dates when ticlc^- cattle are in 

 danger of reinfestation when placed on tick-free land at various 

 times of the year. The first section applies to most localities in the 

 southern linlf of the infested region, and the secoml section to 

 localities having temperature conditions about the same as Knowille, 

 Tenn. 



