in Egypt), pangolin (Howard 1908), zebra in Somaliland (Stella 1939B), baboon (Sudan records above), bushbaby (Villiers 1955 in French West Africa and Sudan record above), okapi in the Congo (Bequaert 1930A). Tortoise (Dönitz 1910B, Neumann 1911). If these remarks refer to the record of Michael (1899) from Lake Urmi, Iran, they are probably based on misidentification of H. aegyptium. Laboratory Hosts See life cycle below. Commensal Rodent Hosts In our field work in various parts of the tropics and sub tropics of the world few commensal rodents have been found to be attacked by immature stages of the kennel tick. In two areas of Puerto Rico, Fox (1950) reported an infestation rate of only 0.5 and 3.2 percent on 1326 Rattus examined. Wild Small Mammal Hosts Pearse (1929) collected specimens from the following animals in Nigeria: two species of hedgehogs, and four rodents (Lemnis_ comys striatus, Taterillus gracilis angelus, Thryronomys swinderianus, and Praomys tullbergi). The identifier and the stage of the ticks were not stated. These are most interesting data that few others have duplicated. In Tunisia, the gundi (Rodentia: Ctenodactylus gundi) is said to be frequently attacked by larvae and nymphs (Chatton and Blanc 1918). The several unusual small mammal hosts found infested in Equatoria Province (listed above) were all taken in association with native villages. The elephant shrew, Elephantulus rufescens hoogstraali, was caught in an island of dense shrub and tree vegetation, among which shepherds and their animals sought refuge from the glaring sun, in the grasslands near a village. The bushbaby, Galago s. senegalensis, lived in a fig tree under which the village elders and their dogs congregated. The two infested tree squirrels, Heliosciurus gambianus hoogstraali, were feeding in a village tree and above a community watering hole, respect ively. The rock hyrax, Heterohyrax brucei hoogstraali, occupied a ledge a few dozen yards above a group of hillside huts. A significant observation of all stages of the kennel tick feeding on European rabbits, Oryctolagus cuniculus, in a forest near Casablanca has been reported by Blanc and Bruneau (1954). In the Yemen, tremendous infestations, representing varying proportions of all stages, were found on all hares examined (Sanborn and Hoogstraal 1953; Hoogstraal, ms.). In Egypt the same is true of hares, some two hundred of which have been examined. Equatoria Province records show numerous adults on hares and grass rabbits (or grass hares, Poelagus), and in Bahr El Ghazal Province all stages were taken from the several specimens of hares. Indeed, it appears that in both the Ethiopian and Palearctic Faunal Re gions of Africa and Arabia, lagomorphs may be exceedingly im portant as secondary hosts or possibly even as primary hosts of all stages of the kennel tick. Yet, there is no evidence available to indicate that domestic rabbits kept in hutches are seriously infested by this parasite, although as a rule merely housing any animal seems to be an important factor leading to its being attacked by this parasite. European rabbits, an integral part of every Bedouin tenthold in Egypt, are usually infested. These rabbits, which seldom venture far from their owners' tents, are carried from place to place in a bag on the side of a camel when Bedouins move in search of pasturage. Out side of Africa, hares have been found infested by notable numbers of this tick in Anatolia (Hoogstraal, ms.). Without going into detail, a survey of field data indicates that hedgehogs may play a role in supporting this tick second only to that of lagomorphs. These spiny insectivores are com monly though seldom heavily infested. In Egypt, most kinds of desert rodents are occasionally infested by larvae and nymphs, as are also grass rats, Arvi canthis n. niloticus, in cultivated areas. These data are too voluminous and complex to evaluate in the present study. It is, however, apparent that in field situations the life history differs from that of urban populations. Avian Hosts It should be of some interest to present the available African records of avian parasitism by R. s. sanguineus in the hope of in stigating further investigation of this subject. The immediate concern over this problem is the fact that specimens from birds in Equatoria Province have much lighter interstitial punctations than those from mammals in the same Province. Material from birds resembles the majority of specimens from northern Sudan and Egypt and is in closer conformity to the general conception of the appearance of this species. Recorded African avian hosts are the following: Ostrich Struthio camelus massaicus in Kenya (Neumann 1911,1912). S. camelus subsp. in Uganda (Theiler, unpublished). S. camelus australis in Mozambique (Santos Dias 1952D). Bustards Lissotis melanogaster in Mozambique Specimens in BM (NH) and from Sudan (Kordofan Province record above). "Greater bustard" in Kenya (Lewis 1934). "Lesser" and "greater" bustards in Sudan (various Province records above). Neotis cafra denhami in Sudan (Equatoria Province records above). Neotis cafra jacksoni in Uganda (Theiler, unpublished).7 Secretary bird Sagittarius serpentarius in Sudan (Khartoum zoo record above) and in Kenya (Lewis 1934). Hornbill Bycanistes albotibialis from Yaounde, French Cameroons (J. Mouchet legit, HH det.). Storks Sphenorhynchus abdimii in the Sudan (Equatoria Province record above). Leptoptilos crumeniferus in Uganda (Theiler, unpublished). Ibis Hagedashia hagedash subsp. (Neumann 1911) and as "Theristicus leucocephalus in Tanganyika (Neumann 1907,1910B). Hawks, Kites, Buzzards, Eagles, and Owls Kite in the Sudan (King 1926 and Khartoum record above). "Large vulture" in the Sudan (Blue Nile Province record above). Butastur rufipennis in Belgian Congo (Bequaert 1931). Eagle owl, Bubo bubo ascalaphus (= Strix ascalaphus) in Egypt (Neumann 1901, 1911). Pigeon "Ringed pigeon" in South Africa (Howard 1908). There appear to be no African records of this tick from domestic fowls. Specimens parasitizing birds are usually found on the crown of the head, near the eyes, around or in the ears, at the base of the skull, or in folds of skin beside the beak. BIOLOGY Laboratory studies on the general biology of the kennel tick are rather complete. However, field biology and ecology have been much neglected. The biology of this form when confined to houses harboring dogs, although accepted as being well known, has not been adequately studied. Numerous biological and ecological questions concerning the kennel tick remain to be answered. Why is the density and distribution of African populations so uneven? What is the significance of morphological variations such as the lightly punc tate forms from Equatoria Province birds in an area where most of those parasitizing mammals are heavily punctate? What "biological strains" or varieties exist in Africa and do some or all of these react with equal facility to domestication? What is the life cycle under field conditions and what are the host predilections of the immature and adult stages away from human and domestic canine habitations? Why does parasitism of persons and bou tonneuse fever - appear to be so much more common in north western Africa than elsewhere on this continent (and why is boutonneuse fever absent in Egypt)? Just what is there about a habitation shared by man and dogs, whether it be an African hut or a Florida mansion, that is so much more attractive to this tick than a fox den in a rocky hillside? Is the greater incidence of parasitism of all domestic non-canine animals in the Near East, as compared with tropical Africa, merely a matter of host availability? These are but a few of the innumerable inquiries that suggest themselves as a result of our lack of specific information concerning this common tick. Life Cycle The life cycle of R. s. sanguineus has been studied, under laboratory conditions, by Christophers (1907), Hooker, Bishopp, and Wood (1912)*, Patton and Cragg (1913) with techniques illustrated, Nuttall (1915), and Regendanz and Reichenow (1931). In the discussion below, less specialized life cycle reports or studies for special purposes are noted following the sum mary of the above-mentioned papers. All observers agree that this is a three-host tick. Varia tion in reports of length of feeding time of each stage may be due to the kind of host used in laboratory experiments (see below). During nonfeeding phases temperature and humidity exert considerable influence on the length of the life cycle. Nuttall concluded that feeding times are constant, irrespective of temperature variations, and that only the nonfeeding phases are affected by these variables (see also discussion of this aspect under H. dromedarii, p. 428). *The extensive data in this important paper are not reviewed here. |