A century of tick taxonomy in South Africa

HORAK, I.G. 2009. A century of tick taxonomy in South Africa. Onderstepoort Journal of Veterinary Re search, 76:69–74 Eighty ixodid tick species, 25 argasid tick species and Nuttalliella namaqua occur in South Africa. Twenty-one of the 80 ixodid species and two of the argasid species occur only in this country, while N. namaqua is present only in South Africa and Namibia. Forty-six of the 80 ixodid species and 16 of the 25 argasid species as well as N. namaqua have been described as new species since 1908. People working in South Africa have written or contributed to the descriptions of 24 of these 63 new species, while foreign researchers have described the remainder. New species indigenous to South Africa are still being discovered, while the names of some species, well known because of their veterinary importance, have been altered.


CONTEXT
T he most recently compiled world list of valid tick names contains the names of 692 ixodid and 186 argasid tick species as well as that of Nuttalliella namaqua, the only species in this genus (Nava, Guglielmone & Mangold 2008).Of these 879 species, 80 ixodid and 25 argasid species and N. namaqua occur in South Africa.Twenty-one of the 80 ixodid species and two of the argasid species have distributions confined to this country (Theiler 1962;Walker 1991;Walker, Keirans & Horak 2000), and N. namaqua has only been recorded in South Africa and Namibia.Forty-six of the 80 ixodid and 16 of the 25 argasid species and N. namaqua have been described since 1908, and this review is confined to the latter 63 ticks.Twenty-four of these descriptions were written, or contributed to by people in South Africa, and the remainder by researchers in England, France, Germany, Israel, Russia, Mozambique and the USA.
The South African authors and the South African ticks that they have de scribed as being new to science since 1908 are summarized in tabular format.A similar format has been followed for tick species with South African distributions, but described by foreign re searchers during the same period.
The earliest description of a tick that has a strictly South African distribution is that by De Geer in 1778 for Amblyomma sylvaticum, a tick of tortoises and more particularly the angulate tortoise, Chersina angulata (Horak, McKay, Henen, Heyne, Hofmeyr & De Villiers 2006).The most recent description is that of Haemaphysalis colesbergensis, a tick of domestic and wild felids (Apanaskevich & Horak 2008c).
South Africans have in recent times also been involved in some of the more controversial name changes of wellknown ticks of veterinary importance.The name changes of the common blue tick, Boophilus decoloratus and the Asiatic blue tick Boophilus microplus to Rhipicephalus (Boophilus) decoloratus and Rhipicephalus (Boophilus) microplus were first published by Horak, Camicas & Keirans (2002) in their world list of valid tick names.
This was done after molecular and morphological studies by Murrell, Campbell & Barker (2000) and Beati & Keirans (2001) had indicated that the genus Rhipicephalus was paraphyletic in respect of the genus Boophilus.Murrell & Barker (2003) later confirmed these name changes.The yellow dog tick of South Africa, previously lumped with Haemaphysalis leachi of North and East Africa, has been reinstated as Haemaphysalis elliptica, an old taxon originally described from the Cape of Good Hope by Koch in 1844 (Apanaskevich, Horak & Camicas 2007).While the bont-legged ticks, to which sub-specific status within the Hyalomma marginatum species group had previously been assigned, have all been raised to specific status (Apanaskevich & Horak 2008a).Furthermore the tick previously known as Hyalomma marginatum turanicum in South Africa has been reinstated as Hyalomma glabrum, the only Hyalomma with a strictly southern hemisphere, and with that a strictly South African distribution (Apanaskevich & Horak 2006).Three of the abovementioned ticks are of considerable veterinary importance in that R. (B.) decoloratus and R. (B.) microplus are the vectors of Babesia species, the cause of babesiosis or redwater in domestic cattle (De Vos, De Waal & Jackson 2004), while H. elliptica, and not H. leachi, is now the only proven vector of Babesia canis rossi the cause of the virulent form of babesiosis encountered in domestic dogs in South Africa (Lewis, Penzhorn, Lopez-Rebollar & De Waal 1996;Apanaskevich et al. 2007).A fourth member of this group, Hyalomma rufipes, is the principal vector in South Africa of the virus causing Crimean-Congo haemorrhagic fever in humans (Horak, Swanepoel & Gummow 2002).The name changes are thus not only of academic importance, but of scientific concern as they are oft used in the literature concerning the diseases that they transmit and in which the correct use of taxonomic epithets is essential.

TABLE 1
Authors who have worked in South Africa and the South African tick species that they have described as new to science since 1908 *Zumpt was working at the Bernard Nocht-Institut in Hamburg at the time he described this species

TABLE 2
Tick species with South African distributions described as new to science by foreign researchers since 1908 TICK SPECIES AND FOREIGN AUTHORS * Ixodid ticks * Not listed in references SOUTH AFRICAN AUTHOR AND SPECIES Bedford, G.A.H.

TABLE 3 South
African ticks, other than Rhipicephalus species, described by foreign researchers, for which additional descriptions have been produced by researchers in South Africa since 1908 SPECIES AND AUTHORS *

TABLE 4
South African Rhipicephalus species described by foreign researchers, for which additional descriptions have been produced since 1908 by researchers in South Africa