Rhipicephalus

Rhipicephalus is a genus of ticks in the family Ixodidae, the hard ticks, consisting of about 74 or 75 species. Most are native to tropical Africa.

Rhipicephalus ticks are commonly called 'the brown tick' as they are mostly brown in colour. Most adult ticks in this genus do not have colour patterns on their scutum (inornate). This makes the species difficult to distinguish from one another because most are quite similar, but individuals of one particular species can be quite variable. Ticks have traditionally been identified by examination of distinctive morphological features. Most of the characteristics used to identify species pertain to male specimens. The immature and female specimens are sometimes simply impossible to identify due to the lack of differential morphological features.

Many Rhipicephalus spp. are of economic, medical, and veterinary importance because of their blood feeding lifestyle. They are possible vectors of many pathogens in humans and animals. They can transmit pathogens that cause animal and human diseases, such as East Coast fever, anaplasmosis, babesiosis, rickettsiosis, Boutonneuse fever, Lyme disease, Q fever, Rocky Mountain spotted fever, and Crimean–Congo hemorrhagic fever. In addition to the infectious agents spread by ticks, tick bites can lead to allergic and toxic reactions. A toxic reaction occur when they inject a neurotoxin with their bite that leads to tick-caused paralysis.

Boophilus was once considered a separate genus, but studies in the early 2000s resulted in Boophilus being made a subgenus of Rhipicephalus. Although Boophilus has been included in the Rhipicephalus genus, their morphology is different from the typical Rhipicephalus species.

Species familiar in the domestic environment include the brown dog tick (R. sanguineus).

Sex pheromone studies
A number of Rhipicephalus spp. females produce phenol and p-cresol after being fed for six days. These compounds may act as sex pheromones since these compounds were shown to be the sex pheromone of Rhipicephalus appendiculatus.

Etymology
The name Rhipicephalus is derived from the Greek word rhiphis, meaning "fan-like", and κεφαλή, kephalē, meaning "head". The two terms are related to the hexagonal basis capituli of Rhipicephalus.

Epidemiology
Rhipicephalus bursa is a carrier of babesiosis, theileriosis and anaplasmosis in domestic animals, of the Nairobi sheep disease, and an aggressive vector of the agents of the Crimean–Congo hemorrhagic fever and of the Q fever.

Species

 * Rhipicephalus appendiculatus Neumann 1901 – brown ear tick
 * Rhipicephalus aquatilis Walker, Keirans & Pegram, 1993
 * Rhipicephalus armatus Pocock, 1900
 * Rhipicephalus arnoldi Theiler & Zumpt, 1949
 * Rhipicephalus australis Fuller, 1899
 * Rhipicephalus bequaerti Zumpt, 1949
 * Rhipicephalus bergeoni Morel & Balis, 1976
 * Rhipicephalus boueti Morel, 1957
 * Rhipicephalus bursa Canestrini & Fanzago, 1878
 * Rhipicephalus camicasi Morel, Mouchet & Rodhain, 1976
 * Rhipicephalus capensis Koch, 1844
 * Rhipicephalus carnivoralis Walker, 1966
 * Rhipicephalus complanatus Neumann, 1911
 * Rhipicephalus compositus Neumann, 1897
 * Rhipicephalus congolensis Apanaskevich, Horak & Mulumba-Mfumu, 2013
 * Rhipicephalus cuspidatus Neumann, 1906
 * Rhipicephalus decoloratus Koch, 1844
 * Rhipicephalus deltoideus Neumann, 1910
 * Rhipicephalus distinctus Bedford 1932
 * Rhipicephalus duttoni Neumann, 1907
 * Rhipicephalus dux Dönitz, 1910
 * Rhipicephalus evertsi Neumann, 1897
 * Rhipicephalus exophthalmos Keirans & Walker 1993
 * Rhipicephalus follis Dönitz, 1910
 * Rhipicephalus fulvus Neumann, 1913
 * Rhipicephalus gertrudae Feldman-Muhsam, 1960
 * Rhipicephalus glabroscutatum Du Toit, 1941
 * Rhipicephalus guilhoni Morel & Vassiliades, 1963
 * Rhipicephalus haemaphysaloides Supino, 1897
 * Rhipicephalus hoogstraali Kolonin, 2009
 * Rhipicephalus humeralis Rondelli, 1926
 * Rhipicephalus hurti Wilson, 1954
 * Rhipicephalus interventus Walker, Pegram & Keirans, 1995
 * Rhipicephalus jeanneli Neumann 1913
 * Rhipicephalus kochi Dönitz, 1905
 * Rhipicephalus leporis Pomerantsev, 1946
 * Rhipicephalus longiceps Warburton 1912
 * Rhipicephalus longicoxatus Neumann, 1905
 * Rhipicephalus longus Neumann, 1907
 * Rhipicephalus lounsburyi Walker, 1990
 * Rhipicephalus lunulatus Neumann 1907
 * Rhipicephalus maculatus Neumann, 1901
 * Rhipicephalus masseyi Nuttall & Warburton 1908
 * Rhipicephalus microplus Canestrini, 1888
 * Rhipicephalus moucheti Morel, 1965
 * Rhipicephalus muehlensi Zumpt, 1943
 * Rhipicephalus muhsamae Morel & Vassiliades, 1965
 * Rhipicephalus neumanni Walker, 1990
 * Rhipicephalus nitens Neumann, 1904
 * Rhipicephalus oculatus Neumann 1901
 * Rhipicephalus oreotragi Walker & Horak, 2000
 * Rhipicephalus pilans Schulze, 1935
 * Rhipicephalus planus Neumann, 1907
 * Rhipicephalus praetextatus Gerstäcker, 1873
 * Rhipicephalus pravus Dönitz, 1910
 * Rhipicephalus pseudolongus Santos Dias, 1953
 * Rhipicephalus pulchellus Gerstäcker, 1873
 * Rhipicephalus pumilio Schulze, 1935
 * Rhipicephalus punctatus Warburton 1912
 * Rhipicephalus pusillus Gil Collado, 1936
 * Rhipicephalus ramachandrai Dhanda, 1966
 * Rhipicephalus rossicus Yakimov & Kol-Yakimova, 1911
 * Rhipicephalus sanguineus Latreille, 1806 – brown dog tick
 * Rhipicephalus scalpturatus Santos Dias, 1959
 * Rhipicephalus schulzei Olenev 1929
 * Rhipicephalus sculptus Warburton 1912
 * Rhipicephalus senegalensis Koch, 1844
 * Rhipicephalus serranoi Santos Dias 1950
 * Rhipicephalus simpsoni Nuttall 1910
 * Rhipicephalus simus Koch, 1844
 * Rhipicephalus sulcatus Neumann, 1908
 * Rhipicephalus supertritus Neumann, 1907
 * Rhipicephalus tetracornus Kitaoka & Suzuki, 1983
 * Rhipicephalus theileri Bedford & Hewitt, 1925
 * Rhipicephalus tricuspis Dönitz, 1906
 * Rhipicephalus turanicus Pomerantsev 1936
 * Rhipicephalus warburtoni Walker & Horak, 2000
 * Rhipicephalus zambeziensis Walker, Norval & Corwin, 1981
 * Rhipicephalus zumpti Santos Dias, 1950

Subgenus Boophilus

 * Rhipicephalus annulatus Say, 1821
 * Rhipicephalus decoloratus Koch, 1844
 * Rhipicephalus geigyi Aeschlimann & Morel, 1965
 * Rhipicephalus kohlsi Hoogstraal & Kaiser, 1960
 * Rhipicephalus microplus Canestrini, 1888 – southern cattle tick