longest sujrvival time for unfed stages of R. appendiculatus ; larvae 

 about nine and a half months, nymphs about^twenty months, and adults 

 about two and a half years. In South Africa, du Toit (1928B) noted 

 the same survival time for advilts in the laboratory and also that 

 unfed adults remained in the field for fourteen months. Nuttall 

 (1913B) was able to keep unfed larvae alive for eleven months 

 (slightly longer than Lewis* observations) but siurvival periods 

 for other stages were shorter than those of Lewis. Wilson (1946) 

 could not maintain unfed larvae in his Nyasaland laboratory for 

 more than a week or so. 



Ecology 



As many as 1000 individuals of this species may be found on 

 single host, most commonly on the ear, on the inner, concave, 

 surface and especially along the anterior margin. When the in- 

 festation is heavy, fewer numbers also attack around the base 

 of the horns, eyelids, cheek, neck, tail switch, udders, scrotum, 

 vnlva, anus, and flanks (Wilson 19483,1949, Beakbane and Wilde 

 1949) . Immature stages are mostly on the ears but not deep in 

 them, as is true of immature R. evertsi . Immature B. decoloratus 

 are frequently associated with R. appendiculatus along the edge 

 of the ear. If the host is heavily infested, immature brown ear- 

 ticks may be foimd on many parts of the animal *s head. Unengorged 

 larvae and nymphs are so small that they are difficult to detect 

 on the host (Wilson 194SC). 



Heavy infestations of brown ear-ticks and of nymphs of R. 

 evertsi on and in the ears of cattle frequently leads to a severe 

 bacterial otitis, caused by Corynebacterium pyogenes , and sloughing 

 of the external ear (Clifford 1954). Dr. J. i. Taylor, recently 

 Director of the Uganda Veterinary Service, states (conversation) 

 that the tympanic membrane is frequently ruptured by heavy infesta- 

 tions and a severe lymphangitis occurs in the head and neck regions. 



In oixier to assess the degree of infestation of cattle in 

 the Lela district of Kenya, an area with about 58 inches of well 

 distributed annual rainfall and with a high average temperatiure 

 and humidity, the East African Veterinary Research Organization 

 (Binns 1951) removed a single animal out of each local herd at 

 fortnightly intervals and collected the ticks from its ears. 



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