Seasonal prevalence of ixodid ticks on cattle in the Windhoek District of South West Africa/Namibia.

The seasonal prevalence of ixodid ticks was determined over a 2-year period by the weekly removal from at least 5 cattle of all adult ticks and the immature stages of Rhipicephalus evertsi mimeticus in the ears. The highest mean weekly burden was 286,6 adult ticks/cow/week in March 1979, and the lowest 6,9 adult ticks/cow/week in July 1979. Virtually no tick control is practised in this area. Rhipicephalus capensis group adults peaked in the summer from October to March/April. Rhipicephalus evertsi mimeticus adults were present throughout the year, though in slightly greater numbers from November to May. Immature stages of this species in the ears showed a peak in February/March in addition to variably-timed high peaks in the first 2 winters. Hyalomma marginatum rufipes and Hyalomma truncatum peaked from December to March. Very small numbers of Boophilus decoloratus and Rhipicephalus oculatus were recovered. Tick burdens of all major species differed significantly in the 2 study years.