2 9 2 



Chapter XXVII 



TICKS 



Ticks or Ixodidae belong to the zoological group of 

 the Arthropods, as among other characters they have 

 jointed extremities ; and they belong to the class 

 Arachnoidea which is characterised by possessing four 

 pairs of legs. In this class occur also spiders, mites, etc. 

 They thus differ from the insects (Insecta) which have 

 only three pairs of legs. They are divided into two 

 sub-families, the Ixodinae and the Argasinae. 



LIFE HISTORY OF TICKS 

 IXODINAE 



Take a neglected dog or other animal infested 

 with ticks, e.g. Eurhipicephalus, place it in a cage 

 entirely covered with muslin.* Next morning remove 

 from the inside females which have left the dog in 

 order to lay eggs, and larvae and nymphs in order 

 to moult. Place in well-plugged test tubes and observe 

 the following stages. 



Egg. The Ixodinae lay several thousand eggs, the 

 process lasting a week or so. The eggs are laid on the 

 earth or by some species by preference in cracks. 

 During the process the head is forcibly flexed on the 

 belly so that the tip of the hypostome touches the 

 vulva. A membrane now prolapses from the opening 

 of the cephalic glajid and protrudes so as to cover the 



* Ticks may be fed on cattle, etc., by placing sleeves on the legs or bags over 

 the ears. 



