Rhipicephalus simus Koch, 1844a

Guglielmone, Alberto A., Nava, Santiago & Robbins, Richard G., 2023, Geographic distribution of the hard ticks (Acari: Ixodida: Ixodidae) of the world by countries and territories, Zootaxa 5251 (1), pp. 1-274 : 129

77. Rhipicephalus simus Koch, 1844a .

Afrotropical: 1) Angola, 2) Botswana, 3) Eswatini, 4) Malawi, 5) Mozambique, 6) Namibia, 7) South Africa, 8) Zambia, 9) Zimbabwe ( Norval & Mason 1981, Walker et al. 2000, Kolonin 2009, Horak et al. 2018, Ledger et al. 2021, Sili et al. 2021).

Keirans (1985b) found more than ten species of Rhipicephalus that have been confused with Rhipicephalus simus . Additionally, Rhipicephalus simus had been extensively confused with Rhipicephalus muhsamae and Rhipicephalus praetextatus prior to the study of Pegram et al. (1987a), who provided characters for separating these species. Nevertheless, Walker et al. (2000) stressed the difficulties involved in morphologically separating adults of the above species, and differentiation of their immature stages is even more problematic, an issue underscored by Horak et al. (2018), who added Rhipicephalus follis , Rhipicephalus gertrudae and Rhipicephalus tricuspis to the list of species whose immature stages can be differentiated from those of Rhipicephalus simus only with extreme difficulty. It follows that several supposed records of Rhipicephalus simus should be treated with caution. The problems involved in precisely identifying Rhipicephalus simus led Walker et al. (2000) to regard the northern limit of this tick as uncertain, and our geographic distribution of Rhipicephalus simus should be considered provisional.

Records of this tick in Egypt are based on specimens collected from imported domestic animals ( Okely et al. 2022). Iori et al. (1996) allegedly collected specimens of Rhipicephalus simus in Somalia. Lynen et al. (2007) listed this tick as found in Tanzania, and Lorusso et al. (2013) classified as “ Rhipicephalus simus group” tick specimens collected in Nigeria, while Wahedi et al. (2020) asserted that Rhipicephalus simus definitely occurs in the lastnamed country. Balinandi et al. (2020) recorded Rhipicephalus simus in Uganda. However, the presence of this tick in Nigeria, Somalia, Tanzania, Uganda and Kenya ( Heylen et al. 2021, Peter et al. 2021) requires confirmation, and we provisionally exclude these countries from the range of Rhipicephalus simus . Records of this tick from Pakistan ( Aziz et al. 2018 and others) and India ( Nataraj et al. 2021) also require confirmation.