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 36. Dermacentor silvarum Olenev, 1931a . Oriental: 1) China (south); Palearctic: 1) China (north), 2) Kazakhstan , 3) Mongolia , 4) North Korea , 5) Russia ( Filippova 1997 , Kolonin 2009 , Chen et al. 2010 , Kiefer et al. 2010 , Černý, J. et al. 2019, Zhang G. 2019, Rubel et al. 2020 , Tsapko 2020 , Guo et al. 2021 ). Dermacentor silvarum is a member of the Dermacentor marginatus species complex and is very similar to another member of the complex, Dermacentor nuttalli , rendering morphological differentiation of these species difficult. Authors such as Khasnatinov et al. (2016) and Bolotova et al. (2017) have referred to this tick as Dermacentor silvarum / Dermacentor nuttalli . Rubel et al. (2020) recognized the presence of Dermacentor silvarum in China (north), Mongolia and Russia , while Perfilyeva et al. (2020) did not list this tick as found in Kazakhstan . Records of Dermacentor silvarum from Kazakhstan and also from North Korea are based on Filippova (1997) and Kolonin (2009) and are treated as provisionally valid here. The presence of this tick in the portion of southern China belonging to the Oriental Zoogeographic Region is based on Chen et al. (2010) , Zhang, G. et al. (2019), Zhang, Y.K. et al (2019), Guo et al. (2021) and Zhao et al. (2021) , who listed Fujian and other southern provinces as being within the range of Dermacentor silvarum . These southernmost records are also considered provisionally valid here. However, additional studies are clearly needed to precisely determine the geographic distribution of Dermacentor silvarum . Hanafi-Bojd et al. (2021) and Ullah et al. (2022) listed Dermacentor silvarum as having been found in Iran and Pakistan (west), respectively, but its presence in those countries needs confirmation.