140 Veterinary Medicine. 



ticks varying slightly from /. Marmorata, have also been found 

 on sheep suffering from louping-ill &nA are therefore suspected. 



I. Chelifer. Pincer Tick. This differs from /. Reduvius in 

 having the third article of the palpi curved inward and pointed so 

 that with its fellow it appears like pincers. 



I. Camelinus found on camels in the Steppes of Asia, and I. 

 RuGiCA and I. Rotundatus found in South America- need not 

 be more than mentioned as having been found on domestic ani- 

 mals. 



Destruction of Ticks. It is easy to kill the tick on the skin 

 by a drop of naphtha, benzine, gasoline, kerosene, oil of turpen- 

 tine, oil of tar, or other insecticide. A drop of oil clcses the 

 breathing stigmata and kills the insect. A hot knife blade or 

 wire applied on the tick causes it to loosen its hold and drop off. 

 In extracting the tick mechanically it is said to be most easily ac- 

 complished by turning it to the left as in extracting a screw. For 

 destroying the ticks upon stock a mixture of oil and some para- 

 siticide, is usually employed. A bath with an inclined plane at 

 each end for the animal to walk in and out, and deep enough to 

 submerge the animal is filled with water on which is floated a 

 mixture (10:1) of crude cottonseed oil, and refined petroleum oil. 

 In walking through, the animal gets an uniform coating of the oily 

 mixture which is destructive to the tick. Another method is to 

 bring the oily mixture through a hose from a barrel placed at a 

 higher level and allow it to flow upon and smear the skin, especi- 

 ally on the ventral aspect and inside the different limbs, the parts 

 most infested by the ticks. To clear a range of ticks, one of the 

 most effective measures is to remove all brush and rank vegeta- 

 gation in which the insect may find shelter. A rotation of culti- 

 vated crops for a series of years will be still better. Cattle having 

 the range of infested wood-lots, should be excluded from other 

 pastures during the hot season. Finally in the case of ticks 

 which attack but one or two species of animals, they may usually 

 be exterminated by dividing the pasture into two halves b}' a 

 double fence and pasturing these on alternate years. On the 

 half which is used for hay the ovigerous female ticks fail to get 

 their supply of blood and fail to produce any eggs or any large 

 number of eggs. For ticks that attack a large number of verte- 

 brate animals of different genera this method would be u-seless, as 

 wild animals cannot be wholly excluded from the field. 



