Ticks found on Man and his Domestic Animals. 323 



boxes moulted into adults in seven to nine days. A number of them 

 died about two to five months after they were removed from their 

 hosts, whilst others, including a male which fertilized a female soon 

 after it had moulted into an adult, still remained alive after six 

 months. 



Megnin states that lie lias kept some nieijuini alive for two years 

 without food. 



Family Ixodidae. 



This is a large family comprising about 220 species. Of these, 

 •iO are known to occur in South Africa. 



Before proceeding to give a short account of each of the most 

 important species, it will first of all be necessary to briefly describe the 

 life cycles of these ticks, as they (the life cycles) are not only different 

 from those of the species belonging to the family Argasidae, but also 

 vary in some of these species, and this is a very important factor one 

 has to take into consideration when exterminating ticks. 



The Life History. 



The engorged females after leaving their hosts search for some 

 sheltered spot on the ground, such as under stones, where thej^ can 

 lay their eggs. The female, when she once starts to lay eggs, con- 

 tinues laying until her body becomes flat and empty, wlieii she dies. 

 The number of eggs laid by a single female varies according to the 

 species, but usuallv several thousands of eggs are laid. The Blue 

 Tick lays 1000-2500 eggs, the species of Brown Ticks from 3000 to 

 5700, the Bont-leg Tick may lay from 10,000 to 15,000, and the Bout 

 Tick about 18,500. 



The eggs may take anything from 18 days to a month or two. or 

 even longer to hatch, the period depending upon the species and 

 climatic conditions. 



The larvae soon alter they have escaped horn the egg are ready 

 to feed, and they then climb up ,a blade of grass or plant and wait 

 patiently for a host to pass by. Should a suitable animal pass within 

 their reach they promptly cling to it by means of their legs, which are 

 provided with claws, and, having selected a suitable spot, insert their 

 mouth-parts into the flesh and commence to feed. On the other 

 hand, should the larvae be so unfortunate as to not meet with a host, 

 which many, in fact the majority, which hatch in the course of a 

 year undoubtedly do, they must of course eventually die of starvation. 



The ticks belonging to this family may be classed into three 

 groups — those which require only one host upon which to complete 

 their life cycle, those requiring two hosts, and those requiring three 

 hosts. 



Group 1. — Ticks which, for the completion of their life cycle, 

 require only one host. To this group belongs the Blue Tick. The 

 larvae of this tick moults into a nymph on its host, and the nymph 

 again moults into an adult on the same animal. Pairing takes place 

 upon the host, and the females drop oft' when they have gorged them- 

 selves'. 



Group 2. — Ticks which require two hosts for the completion of 

 their life cycle. To this group belongs the Red Tick. The larvae 

 moults into a nymph on the host, and the nymph drops off when it 

 has engorged. After remaining on the ground for about three weeks 



