Abstract:
The study aimed to assess the long-term population dynamics of questing Rhipicephalus
appendiculatus and Rhipicephalus zambeziensis in two landscape zones of the Kruger National
Park (KNP). Ticks were collected by dragging the vegetation monthly in three habitats
(grassland, woodland and gully) at two sites in the KNP (Nhlowa Road and Skukuza) from
August 1988 to March 2002. Larvae were the most commonly collected stage of both species.
More R. appendiculatus were collected at Nhlowa Road than at Skukuza, with larvae being
most abundant from May to August, while nymphs were most abundant from August to
December. Larvae were most commonly collected in the gullies from 1991 to 1994, but in
the grassland and woodland habitats from 1998 onwards. Nymphs were most commonly
collected in the grassland and woodland. More R. zambeziensis were collected at Skukuza than
at Nhlowa Road, with larvae being most abundant from May to September, while nymphs
were most abundant from August to November. Larvae and nymphs were most commonly
collected in the woodland and gullies and least commonly in the grassland (p < 0.01). The
lowest numbers of R. appendiculatus were collected in the mid-1990s after the 1991/1992
drought. Rhipicephalus zambeziensis numbers declined after 1991 and even further after 1998,
dropping to their lowest levels during 2002. The changes in numbers of these two species
reflected changes in rainfall and the populations of several of their large herbivore hosts, as
well as differences in the relative humidity between the two sites over time.
