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R. pravus is known only from Eastern and Torit Districts of Equatoria Province. Although absent or rare west of Torit District, apparent ecological preferences indicate that it may be expected to occur in Upper Nile Province, to the north of eastern Equatoria.

Some of the above-mentioned collections have already been quoted by Theiler and Robinson (1953B) and Walker (1956). Except for a few Kapoeta specimens, none from the Sudan have been found in Sudan Government collections or in British Museum (Natural History).

DISTRIBUTION

The drier areas of East Africa appear to be the center of distribution of R. pravus, which also extends into Central and Southern Africa and may range just inside the borders of West Africa. This species is often common in the localized areas where it occurs.

WEST AFRICA: NIGERIA (As R. neavi punctatus: Gambles 1951. Walker 1956).

CENTRAL AFRICA: CAMEROONS (Unsworth 1952). BELGIAN CONGO and RUANDA URUNDI (Theiler and Robinson 1953B,1954, and Walker 1956 presume that R. pravus is the actual identity of the "R.

bursa" of Newstead, Dutton, and Todd 1907; Schwetz 19270; and Bequaert 1930A,1931; however these authors have not examined the "R. bursa specimens in question. Theiler and Robinson 1953B,1954 give the only available definitely correct locality records for this species here. As R. neavi: Santos Dias 1954D).

EAST AFRICA: SUDAN (Hoogstraal 1953B; ms. quoted by Theiler and Robinson 1953B and Walker 1956).

ETHIOPIA (Zumpt 1942C). ERITREA (Hoogstraal, personal col lecting around Asmara; common). FRENCH SOMALILAND (Hoogstraal 1953D. Theiler and Robinson 1953B). BRITISH SOMALILAND (See record of R. pravus with R. longicoxatus, p.. Walker 1956). ITALIAN SOMALILAND (Numerous specimens in Hoogstraal collection. Walker 1956).

KENYA (As R. neavi and as R. pravus: Neave 1912 and Anderson 1924A,B. As R. neavi: Neave 1912; Warburton 1912; Daubney 1934; Lewis 1934,1939A; Mulligan 1938; Lewis, Piercy, and Wiley 1946; Binns 1952; Wilson 1953. As R. neavi punctatus: Lewis 1931C. As R. pravus: Zumpt 1942B; Hoogstraal 1954C; Walker 1956). UGANDA (AS R. neavi: Neave 1912; Mettam 1932,1935; Wilson 1948, 1950,1953. As R. pravus: Theiler and Robinson 1953B,1956. Common in Karamoja District: Haddow, correspondence). TANGANYIKA (Donitz 1910B. Zumpt 1942B. Theiler and Robinson 1953B. Hoogstraal 1954C. Walker 1956).

SOUTHERN AFRICA: ANGOLA (As R. bursa and R. neavi punctatus: Santos Dias 1950. As R. neavi punctatus: Sousa Dias 1950. As R. pravus: Theiler and Robinson 1953B). MOZAMBIQUE (As R. bursa: Howard 1908. As R. punctatus: Santos Dias 1951B,1953A,B. As R. neavi: Santos Dias 19508,1952D,E,H,1953A,B,C. As R. mossam Bicus: Santos Dias 1950B,1952H. As R. piresi: Santos Dias 1950F,1952D,1953B. Synonymy of Santos Dias names by Walker 1956. As R. pravus: Santos Dias 1952D).

NORTHERN RHODESIA (As R. neavi: Warburton 1912. Neave 1912. Theiler and Robinson 1953B. Matthysse 1954. As R. pravus: Theiler and Robinson 1953B,1954. Matthysse 1954). SOUTHERN RHODESIA (Theiler and Robinson 1953B). NYASALAND (As R. neavi and R. neavi punctatus: Warburton 1912. Neave 1912. Davy and Newstead 1921. Wilson 1950B. As R. pravus: Theiler and Robinson 1953B).

BECHUANALAND and SOUTHWEST AFRICA (Theiler and Robinson 1953B). UNION OF SOUTH AFRICA (As R. bursa: Howard 1908. As R. pravus: many details in Theiler and Robinson 1953B).

Note: This species has undoubtedly been much misidentified, but more records for it will probably appear since Zumpt's, Theiler's, and Walker's recent works have established its identity. Many or most records of R. bursa from tropical and South Africa pertain actually to R. pravus according to Theiler and Robinson (1953B), but Lewis' various references to R. bursa in Kenya refer to R. kochi and to R. hurti Wilson, 1954 (Walker 1956) as well as to R. pravus.

HOST S

R. pravus is rather more indiscriminate in choice of hosts than most other rhipicephalids, being common on domestic cattle, sheep, goats, and dogs, equally common on many antelopes and carnivores, and not at all uncommon on hares. Several incidental hosts, from a bird to an elephant, and including man, are listed below. Immature stages utilize rodents and insectivores as hosts.

Adult Hosts

Domestic animals: Cattle (Wilson 1950B, Unsworth 1952, Theiler and Robinson 1953B; Sudan records above; Hoogstraal Eritrean collections. Matthysse 1954 states that this tick is more common on wild game than it is on domestic cattle in North ern Rhodesia). Sheep (Sousa Dias 1950, Theiler and Robinson 1953, Hoogstraal 1953D, Matthysse 1954, Walker 1956; Sudan records above). Goats (Sousa Dias 1950, Theiler and Robinson 1953B, Walker 1956; Sudan records above). Dogs (Sousa Dias 1950, Theiler and Robinson 1953B; Sudan records above). Donkey (Theiler and Robinson 1953B, Matthysse 1954). Camel (Walker 1956. See also British Somaliland record of this species with R. longicoxatus, p. 661).

Man (Sudan records above. Haddow, correspondence).

Antelopes: Reedbuck (Warburton 1912). Kudu (Warburton 1912, Davey and Newstead 1921, Theiler and Robinson 1953B:

Haddow, correspondence). Impala (Warburton 1912, Davey and Newstead 1921, Santos Dias 1952D). Roosevelt's hartebeest (Sudan records above). Bushbuck (Schwetz 1927, Bequaert 1931, Theiler and Robinson 1953B). Sable antelope (Santos Dias 1953D, Matthysse 1954). Eland (Davey and Newstead 1921, Matthysse 1954; Haddow, correspondence). Oryx (Dönitz 1910B, Zumpt 1942B, Theiler and Robinson 1953B). Grant's gazelle (Dönitz 1910B, Zumpt 1942B Theiler and Robinson 1953B). Thomson's gazelle (Walker 1956). Bright's gazelle (Theiler and Robinson 1953B). Gerenuk or Waller's gazelle (Wiley 195 ). Nyala (Santos Dias 1952D, Theiler and Robinson 1953B). Steinbok (Santos Dias 1952D, Theiler and Robinson 1953B). Klipspringer (Theiler and Robin son 1953B). Various oribis and duikers (Wilson 1950B, Theiler and Robinson 1953B, Walker 1956; Haddow, correspondence; Sudan records above). Various dikdiks (Sudan records above; Haddow, correspondence).

Carnivores: Spotted hyena, leopard, lion and genet (Theiler and Robinson 1953B). Jackal (Sudan records above).

Lagomorphs: Hares (Lepus spp.) (Wilson 1950B, Tendeiro 1951A, Santos Dias 1952D, Theiler and Robinson 1953B; Haddow, corres pondence). "Grass hare" (Poelagus sp.) (Theiler and Robinson 1953B; Sudan record above).

Miscellaneous: Buffalo (Dönitz 1910B, Davey and Newstead 1921, Santos Dias 1952D, Theiler and Robinson 1953B, Matthysse 1954). Warthog (Schwetz 1927C, Theiler and Robinson 1953B; Haddow, correspondence). Wild pig (Sudan records above). Giraffe (Donitz 1910B, Theiler and Robinson 1953B). Elephant (Hoogstraal collection from Italian Somaliland). Hedgehog (Sudan record above). Ground squirrel (As R. piresi: Santos Dias 1950F). Rodent listed as 7jerboa by collector, from Kenya (Hoogstraal 1954C). Elephant shrew (insectivore) (Matthysse 1954).

Bird (shrike) ("Telephonus sp.") from Kenya (Hoogstraal

1954CT.

Immature stage Hosts

Antelope (oribi) (Sudan records above).

Hares (Tendeiro 1951A, Santos Dias 1952D,1954C; Sudan records above).

Rodents (Mastomys coucha, Aethomys namaquensis auricomis, and A. chrysophilis) (Theiler and Robinson 19538).

Insectivores Elephant shrews, Elephantulus rupestris and Nasilio brachyrhynchus (Theiler and Robinson 1953B). Elephantulus fuscipes and E. rufescens hoogstraali (Sudan records above), and, species not indicated, from Tanganyika (Hoogstraal 1954C)7

BIOLOGY

Life Cycle

Wilson (1950B) was unable to rear R. pravus under ordinary atmospheric conditions in the laboratory. Theiler and Robinson (1953B) also found this tick difficult to rear, but consider that it is probably a three host type. Lewis, Piercy, and Wiley (1946) had difficulty in inducing larvae to feed on cattle in the laboratory. They concluded that these animals were not suitable as larval hosts but were able to rear R. pravus on rabbits. The original specimens, stage not stated, were found on grass in tsetse infested areas.

Recently, Walker (1956) has obtained life cycle data of the three host type from engorged females maintained at 25°C. to 27°C. Larvae and nymphs were kept between 16°C. and 23°C. Under these conditions, the life cycle was as follows:

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