yio 



ARTHROPODA 



shrivel and to show yellow areas, due to the distention of the 

 Malpighian tubes with guanine. At the end of oviposition the 

 tick dies. 



From the egg comes a six-legged larva, which generally climbs 

 into some grass or bushes and waits to get on to a host. While 

 so doing it may remain for months without food. 



It now sucks blood, and drops off this first host and moults on 

 the ground, becoming an eight-legged nymph, like an adult, but 

 without generative apparatus, which again has to go in search of 

 a second host and obtain a feed of blood, when it drops off and 

 undergoes a second moult, turning this time into the sexually 

 mature adult, which goes in search of a third host. Before feeding, 

 the adult female is small, flat, and thin. When she arrives on the 

 third host she drives her rostrum perpendicularly into the skin 

 as far as its base, a hole being made by the mandibles. 



The palpi do not enter the hole in the skin, but lie on each side. . 



The recurved hooks on the hypostome keep the tick in position, 

 and can only with difficulty be detached. The tick now sucks the 

 blood, and at the same time becomes fertilized and increases enor- 

 mously in size by the addition of blood and the development of the 

 eggs. She then drops off this third host and proceeds to lay her 

 eggs. 



The male does not gorge and does not increase so much in size, 

 but sucks blood, which it requires for its fertilizing work. 

 The Ixodidce are divided into two subfamilies: — 



Subfamily i: Rhipicephalin^ Salmon and Stiles, 1901. 



Synonyms. — Rhipistomidea Koch, 1844; Conipalpi Canestrini, 

 1890; RhipicephalcB l^leumann, 1897; RhipistomidcB M.Q.rx, 1896. 



IxodidcB in which the palpi are no longer than broad. Anterior 

 portion of the body emarginate. 



Type Genus. — Eurhipicephalus Neumann, 1904. 



Genera. — Eurhipicephalus Margaropus, Hcamaphysalis , Derma- 

 centor, Rhipicentor. 



Subfamily 2: Ixodin^ Salmon and Stiles, 1901. 



Synonyms. — Ixodidea Koch, 1844; CuUripalpi Canestrini, 1890; 

 IxodidcB Marx, 18(^2; HcBmatustoridcB Marx, 1892; EschatocepUalidcB 

 Marx, 1892; IxodcB Neumann, 1899. 



IxodidcB with palpi longer than broad; rostrum long. Anterior 

 portion of the body straight or emarginate. 



Type Genus.— /;t:o^^^s. 



Genera.- — Ixodes, Eschatocephalus, Ceraiixodes, Aponomma, 

 Amhlyomma, Hyalomma. 



