Geographic distribution of the hard ticks (Acari: Ixodida: Ixodidae) of the world by countries and territories Author Guglielmone, Alberto A. 0000-0001-5430-2889 guglielmone.alberto@inta.gob.ar Author Nava, Santiago 0000-0001-7791-4239 nava.santiago@inta.gob.ar Author Robbins, Richard G. 0000-0003-2443-5271 robbinsrg@si.edu text Zootaxa 2023 2023-03-07 5251 1 1 274 http://dx.doi.org/10.11646/zootaxa.5251.1.1 journal article 235222 10.11646/zootaxa.5251.1.1 43227427-a867-4744-9e4c-2b2302524890 1175-5326 7704190 3326BF76-A2FB-4244-BA4C-D0AF81F55637 Genus Rhipicephalus Analysis of the geographic distribution of the species of Rhipicephalus is extremely difficult because the diagnoses of several species are, at minimum, controversial, including a number of important species that have not been adequately defined morphologically and molecularly. The seminal study of Walker et al. (2000) , who analyzed the genus Rhipicephalus worldwide, has been of great help in understanding the taxonomy of this genus, but inherent difficulties remain, and these continue to cloud our understanding of particular species’ geographic ranges, many of which are here considered provisional.