H. (H.) marginatum isaaci required a minimum of ror days to complete the life cycle when it behaved as a two host tick and when environment was characterised by hot humid weather. As a three host tick, the life cycle required IOI-I3I days for completion during the months of August to December. Our findings on the life cycle, host preference and length of lite cycle was somewhat different from those reported by RAu (1963) . This may be due to different hosts which were used for the feeding of larva, nymphs and adults and, to sorne extent, due to the differences in temperature and humidity.