678 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



After four months they may be removed back to the original 

 pasture. If, however, no tick-free pasture is available, a different 

 scheme is used. The cattle are moved after as many of the adult 

 ticks have dropped to the ground as are likely to drop off soon. 

 They are then taken to another pasture, still infested at this time. 

 Here they remain not more than twenty days when they are re- 

 moved to a^third field where they remain another twenty days, and 

 then to a fourth field where they remain until they are free of ticks, 

 but from which they are removed before any seed ticks appear in 

 the fifth field. This field is by this time tick-free and the cattle 

 may remain there until the original field has had time to become 

 free, which is usually shortly after this time. The time required 

 depends upon the season of the year in which it is started. The 

 accompanying diagram shows the general scheme of rotation in 

 practice. 



The whole tick-infested area was placed under quarantine in 

 1906 by the Federal authorities and movements of cattle from the 

 quarantined area were permitted only under supervision. Since 

 that time large parts of the quarantined area have been freed from 

 ticks and the quarantine removed. The map shows the wonderful 

 progress of this work. It is surely only a matter of a few years 

 until the Texas fever tick, and with it the fever, will have disap- 

 peared from the United States. 



Dipping Live Stock for Parasites 



Many of the external parasites are best treated by dipping 

 them or immersing them in some solution of an insecticidal nature. 

 Lice, sheep ticks, ticks on cattle and the mites causing mange and 

 scabies all may be killed in this manner. 



Numerous dipping solutions or dips have been tried out and 

 recommended. Only those which are applicable to the majority 

 of the pests in question will be mentioned here. 



Nicotine is a standard dipping material. It should be used at 

 a strength containing approximately five one-hundredths of one 

 per cent of nicotine. This strength corresponds to Black-leaf 

 40 diluted one to 800. Other dips should be used in the same 

 proportionate strength, dilution, for commercial products being 

 usually indicated on the package. 



