382 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 5 



of kerosene. The oxen were then turned into the paddock and al- 

 lowed to remain for three days. The animals were then carefully 

 examined and all the ticks collected, numbering 340 in all. The 

 results may be conveniently tabulated. 



TICKS COLLECTED FROM TEN OXEN 



Total 



A. hebrtEum 



Ixodes pUosus 



R. simus 



R, evertsi 



R. appendicvlalus 



R. capensis 



Hamaphysalis parmata (?) 



11 



250 



n 



44 

 13 



4 



From this experiment it will be seen that the blue tick can be starved, 

 but it also shows that R. capensis seems to have some host among 

 wild animals which has not been observed. Mr. Laws does not state 

 what wild animals may have been running on this area other than 

 hares and duiker (one of the antelopes) — both of which he mentions 

 as being tick infested when shot. 



Not all farmers have all the animals mentioned above, but hares 

 and antelopes are very abundant. Many farms have hundreds or 

 thousands of various antelopes which are not free to be shot even should 

 the farmers so desire. With these conditions it does not seem likely 

 that even the ticks which transmit diseases will be eradicated by the 

 starvation method. Hcemaphysalis^ leachi, the tick which carries 

 malignant jaundice, will probably never be eradicated, as dogs cannot 

 be so readily handled as stock, while ticks such as Hyalomma cegyptium 

 cannot be reduced to any great extent, as the birds will be constantly 

 reinfesting the farm. 



In favour of the starvation method. Dr. Theiler mentions that the 

 freeing of an area from East coast fever is probably due to the starv- 

 ing out of the ticks. He does not mention that the ticks entirely 

 disappeared, but that the area was freed from East coast fever by 

 the removal of the stock for about 15 months. Inasmuch as the 

 organism causing East coast fever does not remain in the blood of the 

 recovered animal, and as the tick cannot transmit the disease after 

 it has attached itself to an animal which does not have the disease, 

 it would seem that the freeing of these areas from East coast fever 

 was not the starvation of the ticks, but the freeing of the ticks of the 

 organisms causing the disease. 



