Tick diversity, abundance and seasonal dynamics in a resource-poor urban environment in the Free State Province

Abstract

The objectives of this study were to determine the diversity, seasonal dynamics and abundance of ticks infesting cattle in urban, small-scale farming communities in and around Botshabelo and Thaba Nchu in the eastern Free State Province, South Africa. A total of ten cattle, ear-tagged for individual identification, were investigated monthly at each of five localities. Adult ticks were removed from the right hand side of each animal and placed in containers filled with 70% ethanol. They were subsequently identified and their numbers quantified. Immature Otobius megnini were counted but not removed. A total of 244 538 adult ticks of ten different species were collected over the 12-month study period. The tick species, in decreasing order of relative abundance, were: Boophilus decoloratus (87,26%), Rhipicephalus evertsi evertsi (6,86%), Hyalomma marginatum rufipes (2,42%), Otobius megnini (1,85%) Rhipicephalus follis (0,76%), Rhipicephalus gertrudae (0,54%), Rhipicephalus sp. (0,21 %), Ixodes rubicundus (0,08%), Hyalomma truncatum (0,01 %) and Margaropus winthemi (0,004 %). The three most abundant species, namely B. decoloratus, R. evertsi evertsi and H. marginatum rufipes, occurred at all localities but with significant differences in abundance. M. winthemi ticks occurred only in the Thaba Nchu area and were not found at any of the three localities in Botshabelo. Significant differences in tick burdens between the six warm months (September to February) and the six cooler months (March to August) were found for most of the species recorded. Boophilus decoloratus occurred in significantly higher numbers in autumn (March to May) and winter (June to August) compared to spring (September to November) and summer (December to February), with 76,8% of the total B. decoloratus burden occurring during the cooler months.