:^2& Journal of the Department of Agriculture. 



Dogs which have harl the disease and recovered retain the infec- 

 tion. 



The Red Tick (Rhipicephalus evertsi, Neu.) 



Cliaracters. — This tick, like all the others belonging- to the genns 

 Rhipicephalus, has a short proboscis and palpi, possess eyes and 

 festoons, and the males have a pair of adanal and accessory adanal 

 shields on the under surface of their bodies. The males c^n easily be 

 recognized by their red legs, black shield (scutum), which is densely 

 pitted, and by the under surface and margin of the upper surface of 

 their bodies being also red. The females also have a dark scutum, and 

 their bodies are dnrk brown wlien unengorged and reddish-brown when 

 engorged. 



This common species is found on all the domestic animals, except 

 pigs, and also occurs on hares and various species of buck. 



The Life History. — It is a two-host tick. The eggs hatch in 

 about thirty days in summer. The young larvae on finding a host 

 usually attach themselves to the ears and flanks, and after gorging 

 moult into nymphs on the animal. After 10-15 days they drop off 

 as engorged nymphae, and moult into adults on the ground in 22-25 

 days. The adults usually attach themselves to the anus or scutum 

 of their host, the females remaining on 6-9 days, and the males much 

 longer. 



Larvae have been kept alive for seven months without food, and 

 the adults for a year. 



Relation to Disease. — The Red Tick is a carrier of one of the two 

 organisms which produce equine piroplasmosis or biliary fever in 

 horses, and has also been proved experimentally to be capable of trans- 

 mitting East Coast fever and a disease formally called " gall-sick- 

 ness " (which ]s produced by the organism Piroplasmu mutans) to 

 cattle. However, the part played by this tick in the transmission of 

 East Coast fever is probably insignificant. All the above diseases are 

 transmitted by the larvae and nymphae feeding on infected animals 

 and transmitting the disease to suvsceptible animals in their adult 

 stage. 



In addition to these, this tick has also been proved to transmii 

 redwater to cattle and spirillosis, which occurs in horses, cattle, and 

 sheep. Both these diseases may be transmitted to susceptible animals 

 by larvae which have become infected through their mothers feeding 

 on an infected animal, and also in the case of redwater, by adults 

 which have derived their infection through feeding on an infected 

 animal in their larval and nymphal stages. 



7' he Brown Tick (Rhipicephalus appendiculatus, Neu). 

 Characters. — This species differs from the Red Tick in having, 

 like the remainder of the ticks belonging to the genus Rhipicephalus, 

 brown legs. The males differ from the other kinds of brown ticks by 

 the punctuation on the scutum being mostly small and not very 

 numerous, especially on the margin. When fully fed the males have 

 a long, pointed tail. The females also differ from the other brown 

 ticks in the size and number of the punctuations on the scutum, but 

 their determination is by no means easy. It is therefore advisable for 

 the farmer to collect the males, which may often be found attached to 

 the under surface of the bodies of the females, and to identifv these. 



