Ecology 



Although H. impeltatum is a tick of arid and semiarid regions, 

 small populations also exist in certain African savannah areas. 

 Biological and ecological characteristics and limitations of this 

 species are still poorly known. As noted above, immature stages 

 are foiond in common association with desert and desert-edge rodents 

 in Egypt. 



In Nigeria, where H. impeltatum is almost entirely confined to 

 the more arid northern provinces, it is sometimes the most common 

 tick collected on cattle and appears to require a drier climate 

 than do H. truncatum (= H. transiens), H. impressum , and H. ru- 

 fipes (tfnsworth 195^) • TSdiiLts are founH around the anus and 

 udders and in the axillary regions of their hosts. 



DISEASE RELATIONS 



Apparently this tick is not a vector of Theileria annul at a 

 of cattle. Note, from Egyptian records, that nymphs and adults 

 are known to feed on man in nature. 



RH>1ARKS 



The comparative size of each stage and sex has been noted 

 by Campana-Rouget (195>+). 



The remarks below are based in part on specimens originally 

 identified (as H. brvimpti ) by Dr. L. P. Delpy, on his remarks 

 (correspondence7 on this material, and on our further observa- 

 tions of additional collections consisting of some 2CX)0 spec- 

 imens. 



IDENTIFICAriON 



Males . In TYPICAL specimens, (l) the exterior position of 

 the comparatively large subanal shields, (2) the lateral grooves 

 that extend anteriorly at least to the scutal midlength, and (3) 



- A57- 



