In Wilson's (1950B) list of nine kinds of hosts of this tick in Nyasaland, no antelopes are represented, and none were included among Howard's (1908) eleven kinds of hosts from southern Africa. The Onderstepoort collection contains only seven collections of glossy ticks from various antelopes throughout Africa (Theiler, correspondence). In addition to the kinds mentioned above, these are a topi from Uganda, a gemsbok from Southwest Africa, and an oribi from Southern Rhodesia.

Other hosts: Elephants In Equatoria Province these animals are either normally attacked by A. tholloni or are free of ticks; but in Bahr El Ghazal Province all elephants examined were heavily infected by R. s. simus and none harbored A. tholloni. Numerous specimens of R. s. simus have been examined in various collections from elephants in other parts of Africa. Others have been reported by Mettam (1932)7. Buffalo These animals are usually infested in the Sudan and frequently harbor numerous specimens of R. s. simus. Elsewhere they are also important hosts of this tick. Records have been published by Neumann (1907,1910B,1911,1922), Davey and Newstead (1921), Bequaert (1930A,1931), Lewis (1931B,C, 1932A,1943), Mettam (1932), and Santos Dias (1952D) 7. Rhinoceroses The black, or narrow-lipped rhinoceros is hardly an important host because it is seldom numerous in nature, but where it occurs most individuals appear to be infested by the glossy tick. See Neumann (1922), Lewis (1932A), Zumpt (1943A), J. B. Walker (un published). The excessively rare white, or square-lipped rhinoceros has been reported as a host by Breijer (1915) and Zumpt (1943A); these reports apply, however, only to the southern race7. Hippopotamus Specimens were found on the ears of three specimens examined in the Sudan; three other specimens were free of ticks. No other records are available 7. Pigs The warthog and bushpig are frequently infested in the Sudan and elsewhere. See Neumann (1901,1907,1910B,1911), Howard (1908), Bequaert (1930A,1931), Lewis (1931B,C,1932A), Bedford (1932), Mettam (1932), Weber (1948), Wilson (1950B), and J. B. Walker (unpublished). Zebras Reported by Neumann (19070,1910B,1911), Lewis (19318,1932A), Mettam (1932), and Santos Dias (1952D) 7. Ant bear or aardvark, Orycteropus afer

Neumann (1922), Bedford (1932), Lewis (1932A), Wilson (1946B, 1950B), Matthysse (1954) 7. African porcupines Neumann (19070, 1910B,1911), Lewis (1932A), Matthysse (1954), J. B. Walker (un published). Pangolin Mettam (1932)7.

Giraffe: Inasmuch as adults commonly parasitize so many large game animals, infestation of giraffes is to be anticipated. However, no published records have been found indicating that this is so. In Bahr El Ghazal Province, where this is a common tick and where numerous giraffes were examined, R. s. simus was not found on these animals.7

Exceptional hosts: Hedgehogs (Howard 1908, Van Saceghem 1914, Bedford 1932B). Hares (Loveridge 1923A, Bedford 1932B, Lewis 1932A). In the laboratory, Lewis (1932A) found that adults feed readily on hares (see also immature stages below). Rabbit (Howard 1908). Cane rats (See also next paragraph. also next paragraph. Sudan records include a single collection from Bahr El Ghazal and the Onderste poort collection contains three lots from Southern Rhodesia). Rodents (South African Otomys, Aethomys, and Rhabdomys; four records: Theiler, correspondence).

?Mistaken identity: Specimens from a cane rat (Bedford 1932B) were later found to be R. simpsoni and not R. simus (Bedford 1934). Neumann's (1922), Mettam's (1932) and Loveridge's (1923A) specimens from cane rats should be checked against R. simpsoni. See HOSTS of R. simpsoni, page

"Large gray cattle tick (?Rhipicephalus sinus Koch) (sic) attached to and completely blocking up the ear opening" of a lizard, Mabuia striata (Loveridge 1923D). This sounds like an Aponomma tick.

Note

Adults, found frequently in rodent nests in which the immature stages feed, are always newly molted, unmated, unfed individuals biding their time before venturing forth to find a host more attractive to them than rodents.

Larval and Nymphal Hosts

Rodent hosts: All of the numerous records of adults in the Onderstepoort collection are from larger size animals and most records of immature stages are from small, nest inhabiting mammals (Theiler, correspondence). Our field experience in East Africa

and Arabia follows the same pattern. The details have been best worked out by Roberts (1935) (also noted by Kauntze 1934) who found the immature stages in the Nairobi area in nests of the following rodents: grass rats or kusu, Arvicanthis sp.; groove-toothed rat, Otomys sp.; striped grass mouse, Lemniscomys sp.; four-striped grass mouse, Rhabdomys pumilio; and multimammate rat, Mastomys (= Mus) coucha.

In the Sudan, some larvae and many nymphs were taken on the same types of animals mentioned by Roberts and also on gerbils, Tatera b. benvenuta. Engorging specimens were taken on these animals trapped away from their nest. We also took a single nymph from two different kinds of hares in two localities but it seems that hares should be considered as exceptional hosts for immature stages. In Northern Rhodesia, Matthysse (1954) also reports larvae from hares.

British Museum (Natural History) collections contain a nymph from another probably exceptional host, a ground squirrel Fermosciurus sp., collected by Karl Jordan in Southwest Africa. A break down of collections of immature stages from South Africa in the Onderstepoort collection (Theiler, correspondence) shows that nine are from hares, two are from springhaas, five from hyraxes, one from ground squirrel; 125 from the following genera of murid rodents: Aethomys (56), Rhabdomys (24), Lemniscomys, Mastomys, Thallomys, Arvicanthis, Rattus, and Mus; and forty from the following cricetid rodents: Otomys (33), Myotomys, Parotomys,

Tatera and Gerbillus.

Other reports of immature stage hosts are short-haired rats, Praomys sp. for larvae (Bedford 1932B) and Praomys jacksoni for nymphs during the dry season around Leopoldville (Wanson, Richard, and Toubac 1947), and an elephant shrew for a nymph "probably of this species" in Kenya (Lumsden 1955).

Exceptional hosts of immature stages in the Onderstepoort collection (Theiler, unpublished) are three elephant shrews and one Crocidura shrew (insectivores), one hartebeest, one mongoose, and one mierkat. Also included are three birds from the region of the Sabi Lundi Function, Southern Rhodesia, the puff_back shrike, Dryoscopus cubla, the blue-breasted waxbill, Uraeginthus

angolensis, and the dusky-faced warbler, Tricholais scotops. It Is difficult to determine whether so many kinds of exceptional hosts are the result of wider and more extensive field search or of ecological differences (see BIOLOGY below).

Laboratory hosts: Lewis (1932A) observed that although nymphs and adults fed readily on hares, larvae were more reluctant to do so. From this Lewis concluded that hares are less preferred hosts of larvae than they are of other stages, an inference that probably should be modified by other biological considerations. At Onderstepoort, both larvae and nymphs feed readily on guinea pigs (Theiler, correspondence).

Questionable remarks and conclusions: Lewis (1932A), after examining Roberts' specimens from rodent burrows, concluded that larvae feed less readily on rodents than do nymphs. Supporting data were not provided but, unless we are still unaware of some unique phase in the life cycle of this tick, it appears that in East Africa, at least, larvae and nymphs attack the same host. Data from collections made throughout the entire year will be necessary before other conclusions can be drawn.

Lewis (1932A) noted a number of larger mammals, from the size of porcupines to rhinoceros, as nymphal hosts, and Stella (1939B) indicated guineafowl. Reidentification of pertinent material is indicated. The Onderstepoort collection (Theiler, correspondence) contains a single collection of nymphs from a red hartebeest in Natal.

Lounsbury (1904A) "wholly failed in attempts to rear larvae on dogs, not one of many thousands applied having fed to reple tion", but later (1906C) succeeded in doing so. The ox was considered an unsuitable host for larvae but "nymphs and adults do not appear to dislike cattle".

Around Lourenco Marques, Sant'Anna (1911) noted, larvae of R. s. simus are encountered and so is a human disease, possibly that now called boutonneuse fever, following tick bites. Sub sequent reviewers have elaborated this remark to indicate that larval simus bite man, and the more enthusiastic have quoted this report as stating that the larvae transmit boutonneuse fever.

BIOLOGY

Life Cycle

Laboratory studies indicate that R. s. simus undergoes a threehost type of life cycle.

Under experimental conditions, Theiler (unpublished), Lewis (1932A), and Lounsbury (1905) have found the life cycle periods

Note: Theiler rearings at 24°C. to 26°C. and approximately 80% R.H.

Hares were used as hosts for all stages in Lewis' experiments, though not with great success. The ease with which these observa tions could be repeated using normal hosts and normal conditions of temperature and humidity found in rodent burrows suggests an interesting study for collecting comparative data.

Field observations indicate that both immature stages feed on nest inhabiting rodents. The nymphal adult molt occurs in the same nest, and adults remain in the nest for some time before seeking larger hosts. As discussed below, a considerable amount

*2 months in winter.