318 Journal of the Department of Agriculture. 



have not previously beeu found on his farm. Should any be found, 

 he should have the animals isolated immediately they arrive, and the 

 ticks destroyed. 



In any case, it is advisable to have all animals dipped, both before 

 they leave a farm and after their arrival on another farm, because 

 animals may be badly infested with both larvae and nymphae of ticks, 

 and these are almost bound to escape notice on account of their small 

 size. 



How many farms in South ATfrica have become infected with the 

 Spinose Ear Tick during recent years tli rough infected stock being 

 transferred from one farm to another? In answering this question 

 one may safely say hundreds, and the reason for this is because the 

 owners of tbese farms did not know anything about the ear tick, and 

 consequently did not have animals' ears examined and treated for 

 ticks when they arrived on the farms. Therefore the importance to a 

 farmer of knowing Ihe kinds of ticks found on his farm and the kinds 

 he is likely to introduce thereon, especially those kinds which are 

 capable of transmitting diseases, cannot be overestimated. 



It is with the object of acquainting the farmer with tlie different 

 species of ticks known to be parasitic upon stock and poultry in this 

 country that this short pamphlet has been written. In it will 1)o 

 found a short resume of the classification of ticks, how to distinguish 

 the different kinds, and notes on eacli species, such as their life- 

 histories, the kinds of animals they are likely to be found on, the 

 diseases they transmit, and any other notes of interest. 



The larvae and nymphae of the majority of species are by no 

 means easy to identify, especially without the aid of a microscope. 

 Tberefore, in tbis paper I have confined myself for the most part t(j 

 ^^iving short descriptions and figures of the adults only. 



The adults of some species can be easily recognized with the naked 

 eye by conspicuous coloured miirkings on the shields and by the colouj' 

 of the leg's; but others, especially some of the brown ticks, require 

 to be examined under a microscope. 



The males are usually easier to determine than the females, and 

 ia order to establish ihe correct species of the latter, it is often advis- 

 able to look for the males, which are often to be found attached to the 

 under surfaces of the females, and to identify these. 



Two other articles, it may be added, are also being published by 

 the Veterinary Research Division, one on the eradication of ticks-, 

 and the other dealing with the diseases transmitted bv ticks. 



CLASSIFICATION OF TICKS. 



Ticks belong to the order Acarina, which also includes the niites. 

 Ticks, and more especially mites, are often spoken of as insects, but 

 they are in no way related to them, being* as they are akin to the 

 spiders and scorpions. 



Ticks, mites and spiders can be distinguished from insects at a 

 glance by the presence of four pairs of legs, at least in the adult and 

 nymphal stages, whereas insects never have more than three pairs of 

 true legs. Insects may also be distinguished by a pair of antennae 

 (feelers) projecting forwards in front of the head, which are never 

 present in ticks and mites, and by their liodies being divided into a 

 number of distinct segments. 



