The dynamics of questing ticks collected for 164 consecutive months off the vegetation of two landscape zones in the Kruger National Park (1988–2002). Part II. <i>Rhipicephalus appendiculatus</i> and <i>Rhipicephalus zambeziensis</i>

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 &lt; 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.

Abiotic and biotic determinants of tick burdens in the eastern rock sengi (Elephantulus myurus)

“…The greater risk of desiccation during hotter periods is likely to be responsible for this relationship (Short et al, 1989;Benoit & Denlinger, 2010) and may constrain questing activity of larvae in this species. This is in accordance with patterns for a number of other South African ticks where immature stages are entirely absent during the hot summer months whereas larval activity peaks in early winter (Spickett et al, 2011). However, T max did not significantly predict nymph burdens indicating that they may suffer less from the risk of desiccation.…”

Ticks and associated diseases: a retrospective review

“…Still lacking are enough longterm surveys. A new standard has been set by a study in which drag sampling for questing R. appendiculatus and Rhipicephalus zambeziensis was performed over 164 consecutive months in South Africa (Spickett et al ., ). The sourcing of funding for such longterm projects is a continuous problem.…”

The dynamics of questing ticks collected for 164 consecutive months off the vegetation of two landscape zones in the Kruger National Park (1988–2002). Part III. The less commonly collected species

“…The numbers of all species collected from the vegetation are summarised in Table 1 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 Year Temperature (C) Spickett et al 2011). Except for Ha.…”