Regulation of seasonal occurrence in the tick Rhipicephalus appendiculatus Neumann, 1901.

Published data on the seasonal occurrence of Rhipicephalus appendiculatus at 8 localities in east, central and southern Africa has been compared and an analysis of the regulatory roles of different climatic factors has been undertaken. It has been shown that the pattern of seasonal occurrence is largely dependent on the timing of the activity period of the adult stage and this is regulated by the combined influences of humidity, temperatures and daylength. By use of a simple model it is shown how the adult activity period in a given climatic regimen can be predicted on the basis of easily obtainable meteorological data. The value of the model in planning tick and disease control programmes is discussed.