TICKS OF THE BELGIAN CONGO. 339 



Sub-genus Aponomma. 



Aponommas may be regarded as merely Amblyommas without eyes or in which 

 the eyes are poorly developed. The body is frequently broad. They occur, in Africa, 

 only on Reptilia. 



Two species are recorded from the Congo :■ — 



(1) Afonomma exornatum, Koch, 1844. The male shows nine light spots on the 

 scutum, of which two are situated on the scapulae, two antero-laterally, 

 one large one centrally and four posteriorly to the foregoing.. There are 

 three spots on the female scutum (fig. 47). 



Fig. 47. Aponomma exornatum 



(Koch 1844), ?: (a) capitulum 



and scutum ; (e) tarsus iv. 



(Neumann, 1899.) 



;2) Aponomyna laeve, Neumann, 1899. Colour light brown, inornate. 



General Biology of Ticks. 



1. Feeding habits. 



All ticks are parasitic and their sole food consists of blood w^hich they suck from 

 their hosts, but at times they may imbibe a certain amount of lymph, if they fail to 

 reach a blood-vessel with their mouth-parts. 



A considerable difference exists between Argasidae and Ixodidae with regard to 

 their feeding habits. The larvae of both groups feed in the same manner as a rule, 

 usually remaining upon the host for less than a Aveek. 



The nymphs and adults of Argasidae, with but one exception {Ornithcdorus 

 megnini in America), are rapid and frequent feeders, filling themselves with blood 

 usually in fifteen to thirty minutes ; they, like bed-bugs, attack their hosts chiefly at 

 night and infest his habitats or resting places. The females lay but a moderate 

 number of eggs, usually less than 200, in batches after each meal of blood. The 

 Argasidae can fast at times for 3-4 years. Both sexes are blood-suckers (0. megnini 

 (5 excepted.) 



The nymphs and adults of Ixodidae remain for a week or more upon the host. 

 The females lay several thousands of eggs, feed but once, and die after oviposition is 

 completed. Partially fed Ixodidae when removed from the host, unless they undergo 

 metamorphosis, usually die in a few days. On the other hand, when unfed, they may 

 remain alive for weeks, months or a year or two, provided the conditions are favourable. 



