ADULT IXODID TICKS ON 2 CATTLE BREEDS IN THE SOUTH-WESTERN FREE-STATE, AND THEIR SEASONAL DYNAMICS

A study was conducted to compare the species of adult ixodid ticks on Friesian and Bonsmara cattle and their seasonal dynamics. Between five and ten animals of each breed were kept on natural False Upper Karoo vegetation, typical of the south-western Free State. Between May 1990 and October 1991, the animals were examined once or twice a month for the presence of adult ticks which were removed, counted and identified . Six species of ixodid ticks were recorded. The species composition o n the two cattle breeds was remarkably similar. Ixodes rubicundus was dominant (55-57,7% of all ticks collected), followed by Hyalomma margi natum rufipes (28,9-31,5%) and Rhipicephalus punctatus (6,2-6,7%). Onl y small numbers of Hyalomma truncatum, Rhipicephalus evertsi evertsi a nd Rhipicephalus gertrudae were recorded. Almost twice as many ticks w ere collected from Friesian as from Bonsmara cattle. Ixodes rubicundus showed a typical winter-activity period. The other species were eithe r active mostly during the warmer months, or their numbers were too lo w to determine any seasonal pattern. Apart from information on the div ersity of ticks which infest cattle in the region, the study has also shown a greater resistance by Bonsmara cattle (a mixed Bos taurus/Bos indicus breed) to tick infestation. Sos indicus cattle can play an inc reasingly important role in integrated tick-management practices in so uthern Africa.