SOME PESTS OF OHIO SHEEP 63 



sheep. Since the sheep tick remains upon the animal during its 

 entire life cycle it will be necessary in order to combat it to use 

 some substance upon the animal that will kill the ticks and still not 

 injure the sheep or its fleece. 



Dipping or immersing the infested sheep in a liquid that will 

 kill the ticks is the most practicable method known for eradication. 

 The dips generally recommended for this purpose are those contain- 

 ing arsenic or nicotine as the active principle, and the coal-tar or 

 cresylic acid dips. These dips are manufactured and sold for this 

 purpose and care should be exercised to follow closely the directions 

 supplied by the manufacturer. Under no consideration should one 

 attempt to make and use a home-made arsenic dip without reliable 

 instructions and guidance. One sheep owner attempted this and 

 lost a considerable number of sheep out of his flock and nearly 

 poisoned himself. If after following the directions closely the dip 

 used does not eradicate the ticks, notify the Ohio Agricultural Ex- 

 periment Station, Wooster, or the Federal Insecticide Board, Wash- 

 ington, D. C. 



From 10 days to 2 weeks after shearing is generally considered 

 the best time for dipping, as the shear cuts are then generally 

 healed. It is dangerous to dip sheep in some of the dipping pre- 

 parations if there are any fresh wounds upon the animals. How- 

 ever, sheep may be dipped at any other time during the summer or 

 early fall if they are found to be infested. Even during the win- 

 ter, according to some authorities, they may be dipped with reason- 

 able safety if the dipping for the day is finished by noon so that the 

 flock may have time to dry off and fill up with feed before night. 

 Others state that dipping in the winter is too severe and should not 

 be practiced. 



The problem of safely and effectively combating the tick in 

 winter is yet unsolved. Spotting, or pouring the liquid along the 

 back and allowing it to run down into the wool is sometimes re- 

 serted to. This remedy, however, should not be considered as final, 

 for at best it kills only a few of the ticks. The infested flock will 

 have to be dipped in the spring. The use of an insecticide powder 

 suggests itself since this form of treatment has been very effective 

 against external parasites upon other animals 



During the winter of 1917 the Ohio Experiment Station con- 

 ducted an experiment to test the effectiveness of pyrethum and the 

 Cornell (Lawry) powder as a remedy for ticks. The powder was 

 applied by means of a shaker made by punching holes in the lid of a 

 tin can. The wool was spread apart by the person holding the 



