Abstract:
1. The descriptions of the adults of H. aciculifer, H. parmata and H. silacea and of the immature stages of H. parmata are brought up to date.
2. The larvae and nymphae of H. aciculifer and of H. silacea are
described for the first time.
3. The discontinuous distribution of H. aciculifer in the Union is shown
to be due to the facts (a) that this is an introduced tick, (b) that the introduced
cattle distributed from dispersal centres, were only sent where they were needed and not to all farms in any given region, (c) the tick only managed to maintain itself in those areas where conditions were favourable.
Cold and frost seem to be the factors limiting its distribution.
4. H. silacea is shown to be confined to the Fish River Bush, so characteristics of certain parts of the Eastern Province of the Cape Colony.
