HYALOMMA 



INTRODDCTION 



The genus Hyalomma is a complex of a few species exhibiting 

 an almost endless varxety of facies. Its original center of dis- 

 persal was probably Irsin or southern Russia. Genetic instability 

 may in part accoiint for the wide morphological differences found 

 in many specimens. Environmental vicissitudes are xmdcubtedly 

 important additional factors in modifying size, color, and over- 

 all appearance in this genus. These are tough, hardy ticks that 

 survive under conditions in which all other species are uncommon 

 or entirely absent; they may even thrive in such environs. They 

 inhabit country where humidity is frequently low, seasonal climatic 

 conditions are extreme, favorable niches for development away from 

 the host are rare, smaller animals for immature- stage feeding are 

 sparse, and larger-size hosts are frequently poorly nourished and 

 wander widely among inhospitable situations. 



Owing to their medical and economic importance and the pressing 

 need to clarify the relationships of all presently recognized spe- 

 cies in the genus Hyalomma , the plan of this section has been mod- 

 ified to include a key to all species and illustrations of non- 

 Sudanese species. Further research will somewhat modify present 

 concepts but this compilation of information will provide a firmer 

 foiandation for subsequent revision than is now available without 

 considerable background study. The presently recognized species 

 of continental Africa are, however, fairly well stabilized and 

 the disconcerting prospect of further nomenclatorial changes and 

 addition of new species applies chiefly to populations from the 

 Near Elast to the Far East. 



NOMENCLATORIAL BACKGROUND 



HISTORY 



It is hardly surprising that criteria for identification 

 of Hyalomma species have long been in a chaotic state. The thir- 

 teen species described by Koch (IB/X) , when he erected the genus. 



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