Plants Used for Tick and Tick-Borne Disease Control in South Africa: Ethnoveterinary Knowledge, Bioactivity Evidence,...

Ticks and tick-borne diseases (TBDs) impose a heavy burden on South African livestock systems, particularly in resource-limited communal areas. Conventional acaricides are effective but face rising challenges of resistance, high costs, and concerns for environmental and human health. As a result, there is growing interest in plant-based tick control rooted in ethnoveterinary knowledge. This review examines the landscape of South African ethnoveterinary practices for tick control and assesses the supporting evidence of bioactivity and pathways for translating these remedies into safe, registered products. A narrative review method was applied, drawing on the literature (2000-2025) from databases and local repositories, with emphasis on South African studies documenting plant use against ticks. Communities in Limpopo, Eastern Cape, KwaZulu-Natal, and other provinces utilise a diverse range of botanicals (e.g., Lippia javanica, Tetradenia riparia, Clausena anisata, Tagetes minuta, Melia azedarach, Eucalyptus spp., Cymbopogon spp.) to repel or kill ticks, often through topical applications, fumigation, or livestock housing treatments. Laboratory assays have confirmed acaricidal or repellent activity in many of the cited taxa. For example, Lippia javanica and Tagetes minuta oils demonstrate strong tick repellency, while extracts of Tetradenia riparia and Calpurnia aurea exhibit greater than 70% mortality in vitro. Field studies are fewer but promising: a community-led trial with L. javanica leaf spray achieved substantial tick reduction (albeit slightly less efficacious than synthetic amitraz). Key gaps include standardisation of plant preparations, safety evaluations (toxicity and residue studies), and alignment with regulatory requirements. Recent regulatory updates in South Africa (Act 36 of 1947) underscore the need for quality, safety, and efficacy data but also create avenues for low-risk botanical remedies. Ethnoveterinary plants offer a culturally appropriate and eco-friendly complement to conventional acaricides. Bridging the gap to practical use will require multidisciplinary efforts: validating efficacy in well-designed field trials, ensuring consistency in preparation, assessing safety margins, and navigating registration pathways for plant-based stock remedies. With supportive policy and community engagement, South Africa could pioneer farmer-ready botanical acaricides that mitigate resistance, reduce costs, and advance One Health objectives.