the same unique ecological zones due to movements of wild hosts or 

 of domestic hosts. They are sympatric species in which hybridiza- 

 tion is not known to occior. 



The highland range of R. compo situs is confirmed by the care- 

 ful study of numerous recor3s by Theiler, Walker, and Wiley (1956). 



Sudan specimens from a buffalo near Niraule, which is a savaru 

 nah area at the level of the Nile River, 2,059 feet elevation, 

 might appear to be exceptions to the highland concept of this 

 species. They were, however, collected in December, shortly after 

 the end of the rainy season, when there is a tremendous movement 

 of outlying animal populations towards the river. It seems protu 

 able that the buffalo from which these ticks were taken had re- 

 cently come to the river from the nearby Acholi mountains, where 

 he had acquired these parasites. 



In Nyasaland, adults were collected only in December and Jazu 

 uary (middle rainy season), when adults of the closely related R, 

 capensis were absent (Wilson 1950B). *" 



Matthysse (195^4-), working in Northern Rhodesia, considers it 

 noteworthy that adults of R. compo situs preceed those of R. appeix . 

 diculatus , being found abundantly before the rains, in Septemoer 

 and October, and also being present in July, August, and November. 

 Rains commence in November. This factor may be of importance in 

 the transmission of East Coast fever diiring the absence of adiilt 

 brown ticks. "Cattle examinations during the latter part of the 

 dry season and during the early rains will show many brown ticks 

 on the undersides of the body, in the tail brush, and on the 

 feet, but not in the ears. These ticks are largely R . compo situs * 

 (= R. ayeri) (Matthysse 1954-). The same author list's a single 

 collection from the ears of cattle. 



DISEASE RELATIONS 

 CATTLE: A vector of East Coast fever (Theileria parva ) . 



- 626_ 



