Abstract:
Feeding under constant cold conditions resulted in a marginal shortening of feeding period and a major
shortening of the subsequent developmental phase of all stages of Ixodes rubicundus Neumann 1904, the Karoo
paralysis tick. Paralysis occurred in laboratory rabbits when nymphae were fed on them under constant warm,
constant cold and fluctuating ambient winter conditions. This paralysis was found to be dependant on infestation
rate and feeding conditions. Under constant cold conditions paralysis resulted from lower levels of infestation
than under warm or under fluctuating winter conditions. Neurological parameters used in assessing the progression
of the paresis are discussed.