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Wild mammals: Insectivores: Hedgehog (Wilson 1950B, Sudan record above). Madagascar tenrec (Hoogstraal 1953E). Carnivores: Jackal (Neumann 1902B, Lewis 1934, Matthysse 1954, Sudan records above). Cheetah (Wilson 1950B). Long-eared fox, Otocyon megalotis (Lewis 1934). Spotted hyena and mongoose (Sudan # 8 OOWe We Lagomorphs: Hares (Wilson 1950B, Matthysse 1954, Sudan record # Rodents: Cane rat (Wilson 1950B, Bahr El Ghazal record above). Ground squirrel (Sudan record above). Antelopes: Hartebeest, Thomson's gazelle, klipspringer (Lewis 1934). #er. defassa waterbuck (Tendeiro 1947). Waterbuck in Uganda and "forest antelope" from Rio Muni (HH collection). Oribi (Hoogstraal 1954C, Sudan record above). Sudan records are from Bright's gazelle, Roosevelt's duikerbok, Smith's long-snouted dikdik, oribi, common eland, Roosevelt's hartebeest, tiang, and buffalo. Nymphs are especially numerous on tiang in Bahr El Ghazal Province during the dry season. In Northern Rhodesia, Matthysse (1954) found all stages on zebras.

Wild birds: Coucals, various (Theiler, unpublished. Hoogstraal 1953E). Ground hornbill, Bucorvus abyssinicus (Warburton 1:# Raven (Hoogstraal 1954C). Spurfowl (Pternistis sp. or Francolinus sp.) (Lewis 1934, various Sudan records above). Long-legged bustard and hooded vulture (Theiler, unpublished). Guinea fowl (Lewis 1934 and Sudan records above). Abdim's stork, lesser bustards, tchagra shrike (Sudan records above). An undetermined passerine bird (arveola) (Tendeiro 1952C). For domestic birds, see Domestic animals above.

Reptiles: Chameleon in Madagascar (Hoogstraal 1953E).

Larval Hosts

Man has been listed as a larval host by Wilson (1950B). Larvae commonly attack man at the beginning of the dry season in Upper Guinea, French West Africa (Joyeux 1915). In Cameroons they are serious pests of man (Rageau 1953B) and attach on the legs and about the belt. Ziemann's (1912B) mention of being badly bitten by tick larvae in the Cameroons may refer to this species. According to De Meza (1918A), in Nyasaland larvae are serious pests of people working about cattle. Larvae just visible to the eye burrow under the skin of human legs and cause severe irritation that may be associated with rash and pus if the ticks are numerous.

Birds: Spurfowl (Pternistis sp. or Francolinus sp.) (Lewis

1932B). Helmeted £ fowl (Lewis 1934). "Rural Tchickens's alinha do mato) (Tendeiro 1952C). Lesser bustard (Sudan record #

Mammals: Hare (Lewis 1934). Reedbuck (Lewis 1931C). Zebra and jackal (Matthysse 1954). Genet, jackal, and mongoose (Sudan records above). Domestic goat (Lewis 1934, Sudan record above) and cattle (Lewis 1931C, Sudan record above). Domestic dog in Madagascar (Hoogstraal 1953E).

Stage not stated but probably immature

Hedgehog (Atelerix spiculus) and gerbil (Taterillus gracilis elus) (Pearse 1929). # (Atelerix albiventris Wagner) # A. adansoni Roch.) and white-tailed mongoose (Ichneumia albicauda) (Rousselot 1951).

BIOLOGY

Life Cycle

This three-host tick is frequently the most common cattle parasite within its range. Hosts of each stage are listed above. Most workers have experienced difficulty in rearing A. variegatum but J. B. Walker states (correspondence) that she finds this species quite easy to rear. With nonfeeding ticks maintained at from 25°C. to 279C., the minimum periods for the life cycle are as follows:

PERIOD DAYS (Minimum)

Walker Lewis Lewis
1932A 1939B

Preoviposition l2 13 (24-27°C)
Oviposition to hatching 53 86 (19-26°C)
Larval prefeeding period 7 7
Larva feeds 5 7 5-3
Premolting period l4 22 (25-279C)
Nymphal prefeeding period 7 7
Nymph feeds 5 7 6-13
Premolting period 19 24 (24-27°C)
Adult prefeeding period 7 7
Adult (Female) feeds l2 10 l4-22
Total l4l 195 -

The prefeeding periods in the above table are arbitrary and in nature may be shorter than the figures indicate. Walker fed larvae and nymphs on a rabbit and adults on a ram. Lewis (1932A) used hares, chickens, and sheep as hosts.

Nuttall (1915) recorded attachment periods twice as long as Lewis' and stated that males may remain on the host for from four to eight months, and may even die there. At 30°C., larvae emerge from eggs after sixteen to 31 days; at 15°C. larvae fail to hatch.

On the other hand, Mettam (1933) reported that in his Uganda laboratory "times occupied during feeding, molting, etc. are much shorter than the one obtained by . . . . . . . Lewis", but these observations apply only so far as the nymphal stage.

Larvae feeding on man drop off the host after twelve hours (Joyeux 1915).

Under laboratory conditions, the longevity of A. varieżatun (? unfed adults - HH) is 732 days (Lewis 1939B).

In those parts of its range with but one rainy season annually, the tropical bont tick has only a single generation a year, as reported for Ilyasaland by Wilson (1950B) and for Northern Rhodesia

by Matthysse (1954). In Kenya and Uganda, with two rainy periods each year, multiplication is faster and two or three generations may breed during a twelve months' period (Wilson #3%

Females engorge and oviposit during the wet months, larvae engorge early in the dry season, and nymphs live through the dry season. The periods of preoviposition and embryonic development in nature should be more carefully investigated. A delay or diapause phenomenon of some three months or more for these combined periods in the rainy season appears likely.

Ecology

The typical seasonal cycle, as explained for Northern Rhodesia by Matthysse (1954), applies to the Sudan and other single rainy season areas of Africa. Details for other areas with two rainy seasons are not certain, and there appears to be more overalpping of different stages in such situations. Adults appear towards the end of the dry season, first males and then females. Populations increase in numbers and remain high through the rainy season and decrease rapidly in the dry season, although a few specimens may be found even then. Larvae and nymphs gradually become more numerous in the dry season, and while some nymphs are found during the rains they are scarce.

Adults and nymphs are most common on the udders, scrotum, flanks, dewlap, and brisket; larvae feed on the ears and head of the host (Wilson 19.33,193). Beakbane and Wilde (1949) also noted adults on the perineum and indicated means of control with respect to the feeding sites of ticks infesting cattle.

In Cameroons, larvae of this tick have been observed in immense numbers on tall herbage along paths, waiting for a suitable host to pass (Rageau 1953B). Similar, vivid remarks by Ziemann (1912B) for Cameroons suggest that his observations may also have referred to A. variegatum.

"The fully fed female of A. variegatum works her way into the soil to lay her eges, and unfed ts are frequently seen, waiting for a passing host on the foliage of bushes three or four feet high" (Lewis 1934).

A. variegatum has been found from sea level to 8500 feet elevation. In the Yemen (Arabia), this species is common on cattle in well vegetated valleys and hillsides between 2500 and 5000 feet elevation, but absent in deserts at lower elevations and rare in more barren higher elevations (Hoogstraal, ms.). Franchini's (1930) record of A. variegatum from Hodeida, on Yemen's coastal plain, is due either to erroneous locality labels or represents specimens from highland cattle arriving for slaughter. This species is common at Asmara, Eritrea, 7500 feet elevation (HH collecting), but Schoenaers (1951B) states that it does not occur over 2000 meters (6500 feet) elevation in Ruanda-Urundi.

In East and Central Africa, Wilson (1953) has nicely defined the presence of two very distinct ecological relationships between ticks and cattle. One of these, the R. appendiculatus-A. variegatum association, occurs in areas with rainfall well above 25 inches per annum (and is of considerable importance in relation to East Coast fever and heartwater transmitted to cattle by the respective ticks). The second, the R. pravus (= R. neavi)-A. gemma association, occurs where rainfall very seldom exceeds twenty or 25 inches per annum (and is of negligible veterinary importance). For a summary of Wilson's second association, see # pravus (page 681).

The distribution of the R. appendiculatus-A. variegatum association corresponds to what veterinarians previously referred to as "dirty areas" (i.e. East Coast fever endemic areas). As stated above, rainfall here is at least 25 inches annually, usually well above this figure, and falls below this level only once in every twenty or 25 years. This association includes the highlands of Kenya and Tanganyika, a 25 to thirty mile belt bordering Lake Victoria in Kenya, Uganda, and Tanganyika, and continues down the Rift Valley in the country adjacent to Lake Tanganyika and Lake Nyasa, and (a short distance) into Mozambique. It also includes the humid seacoast plains, which are only a few miles wide in Kenya but much wider in Tanganyika. Within drier areas (i.e. those of the first association) are isolated islands in the "rain shadow" of hills and mountains where higher precipitation results in more dense vegetation than that of the surrounding plains. In these islands, the R. appendiculatus—A. variegatur association persists. The soil and vegetation on which this association occurs vary tremendously with slope of terrain, altitude, underlying rock formation, and temperature. The single common factor in their

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