322 Journal op the Department of Agriculture. 



Duiiug- tile last few years Jt lias sprejid rapidly throughout the 

 Cape Province, Orange Free State, and Bechuanah^nd. It is also 

 found in parts of Natal and the southern portion of the Transvaal. 



The ticks are only found in districts where the rainfall is very 

 low, and even in those districts become less numerous after heavy 

 rains. » 



They are found only in the ears of their hosts, and usually find 

 their way to the meatus of the ears. They are chiefly parasitic upon 

 calves, sheep, and goats, but horses, donkeys, dogs, cats, and ostriches 

 are also attacked, and so is man ocasionally. The fluid these ticks 

 inject into their hosts whilst feeding causes great irritation, and the 

 result is that animals badly infected with these ticks fall off in con- 

 dition and lose their appetite. Calves, sheep, and goats have been 

 known to succumb when very badly infected. • 



The adults are fiddle-shaped, brown or slate in colour, with yellow 

 legs, and without eyes. In general appearance they somewhat 

 I'esemble the Tampan Tick, but can be distinguished from that species 

 by the shape' of their bodies, and also by the integument, which is 

 pitted in this species and mammillated (covered with small pimples) 

 in the Tampan. 



The nymphae can be distinguished by the surface of their bodies 

 being covered with small outstanding spines, which can be easily seen 

 by the aid of a pocket lens. 



The larvae are pale in colour when they first hatch out, but after 

 engorg-ing they become swollen, white or red in colour, and their legs 

 and head can, as a rule, only be seen wlien the tick is examined with a 

 pocket lens. These engorged larvae are imable to move, and are 

 often mistaken by farmers for eggs. 



The Life Cycle of this tick is as follows: — The female ticks lay 

 their eggs under stones on the veld, in cracks and crevices of trees, 

 gates or walls, or in any other place where they can get sheltered 

 from the sun. These eggs hatch out in about twenty-two to fifty-six 

 days, and give rise to six-legged larvae, which, as soon as they have 

 liatched, crawl about in search of a host, and as soon as they find one 

 they get into its ears and there commence to feed. The longest time 

 the larvae are able to live without food is about two to four months. 

 After engorging, which takes about five to 7 days, they become 

 quiescent, and are then unable to move until they have cast their 

 skins and become nymphae. The length of time the nymphae remain 

 on their host varies considerably. The shortest time in which they 

 can engorge themselves appears to be about a week, but may be con- 

 siderably prolong'ed in some cases. Hooker, in America, has observed 

 a nympha to abandon its host's ear thirty-five days after the larva had 

 been introduced, and in other cases the nymphae remained attached 

 aftei ninety-eight days had elapsed. Nymphae have also- been 

 observed at Onderstepoort to remain in the ears of their hosts for three 

 months. When engorged they leave their host and crawl about in 

 search of some sheltered spot where they can change into adults, which 

 takes from seven to thirty-one days. They then fertilize, and then 

 the females commence laying eggs, after which they die. 



It is not necessary for the adults to nourish themselves before 

 copulating and ovipositing, as they are able to store up enough food 

 in the nymphal stage. Engorged nymphae collected from the ears of 

 their hosts in November, 1916, and kept in the laboratory in wooden 



