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A. nuttalli is widely spread throughout the African continent within the Ethiopian Faunal Region.
WEST AFRICA: NIGERIA (Simpson 1912A,B. Robinson 1926). GOLD COAST (Robinson 1926. Stewart 1937). FRENCH WEST AFRICA (Williers 1955). PORTUGESE GUINEA (Tendeiro 1951C,D,1952A,0,D,1953, 1954).
CENTRAL AFRICA CAMEROONS (Dönitz 1909. Rageau 1951,1953A,B). #"T- 1927C. Bequaert 1931. Theiler and Robinson 1954).
EAST AFRICA: SUDAN (King 1926. As A- W* werneri: Schulze 1932A.THoogstraal 1954B).
ITALIAN SOMALILAND (See REMARKS below).
KENYA (Loveridge 1929. Bequaert 1930A). UGANDA (King 1926, see DISTRIBUTION Ili THE SUDAN above. Robinson 1926. Mettam l932. Wilson 1950C). TANGANYIKA (Dönitz 1909. Robinson 1926. Love#x as A. marmoreum is actually A. nuttalli, see Bequaert 1930A).
SOUTHERN AFRICA: SOUTHERN RHODESIA (Dönitz 1909. Jack 1942). MOZAMBIGUE (Santos Dias 1949B,1950A,B,1951A, 1952D,1953B,1955A,B). UNION OF SOUTH AFRICA (Curson 1928. Alexander 1929, 1931. Bedford 1932. Neitz 1948).
All authors list land tortoises (Kinixys spp. or Geochelone dalis) as the chief hosts of adult A. nuttalli. A record of the side-neck turtle, Pelomedusa s. subrufa (= P. galeata), as a host (Santos Dias 1953B) was based on misidentification of Pelusios s. sinuatus, "a species of lesser importance as a host" (Santos Dias T555E).
Infrequent hosts of adults are monitor lizards (Varanus spp.) (Robinson 1926, Tendeiro 1951D, and Sudan record above), Agama lizard (Loveridge 1929, Bequaert 1930A), python (Bedford ), hedgehog (Robinson 1926), man (Schwetz 1927C), and one specimen from a domestic goat (Theiler, unpublished).
Nymphs and Larvae
Immature stages infest tortoises and also Waranus lizards, birds, and hares. Guineapigs may be used for laboratory rearing. Owing to the paucity of field records for immature stages it is impossible to determine their host preference in nature. It is unusual to find a tick that normally feeds on warm blooded animals in the immature stages and on cold blooded animals in the adult stages; the reverse is usually true. Yet Theiler (correspondence) has nymphs from South African hares and from a turkey on a farm where the mountain tortoise is also common. Further field study of this matter is indicated but, as A. nuttalli appears to be curiously localized and seldom abundant, the success of such investigation will depend on local factors. Note that in Equatoria Province, single nymphs were found on each of two species of Varanus lizards, on an oribi (antelope), and on a francolin partridge, but none were taken from the many tortoises examined.
Various literature records for "iguana" lizard, a non-African reptile, should be "leguan" or monitor lizard (Varanus spp.).
Alexander (1931) was unable to induce adults to feed on laboratory animals.
See also BIOLOGY below.
Santos Dias (1950A) reared this species using guineapigs and tortoises as hosts. He subsequently reported (1955B) that the life cycle is a three-host type. A maximum of 22,891 eggs from a single female were noted with the claim that this is the greatest number of eggs yet observed in any of the Ixodoidea. The minimum period for completion of the life cycle is estimated at 134 to 151 days, the maximum period 217 to 296 days. This paper
is illustrated with photographs of both sexes feeding from the interstices of the host's shields. Our Torit adults, however, were taken in the host's axillae (during a native big-game hunt and stored in a hunter's ear, plugged with mud, for three hours until our lost vials could be recovered).
Experimental attempts to transmit heartwater (Rickettsia ruminantium) of cattle by this tick species have failed.
It is claimed that specimens have been found infected with Q fever (Coxiella burnetii) in Portugese Guinea.
As with the Aponomma parasites of lizards and snakes, it is of interest to conjecture that the small reptile-amblyomma may be a vector of the hemogregarines of tortoises.
Misshapen specimens have been reported (Santos Dias 1949B, 1950A, 1955A).
Amblyomma werneri werneri Schulze, 1932(A), described from Kinix's E. belliana (see Werner 1924) from Talodi, Kordofan, Sudan, appears to be a synonym of A. nuttalli. Following Schulze's practice of applying species names to any variant, he distinguished a single specimen as different from A. nuttalli for the following reasons: the dark marking not blackish-brown, but light red brown on a light reddish brown background; darker markings bounded with a coppery color (in A. nuttalli dark yellow brown without copper borders); median stripes more irregular than in A. nuttalli and broadened at the ends; lateral groove sharply defined against the scutum, in A. nuttalli irregular; and ventral median muscleplate smaller.
All characters proposed to separate A. werneri from A. nuttalli
fall well within the normal range of variation due to age, nutrition, or methods of preservation. In long series of any Amblyomma species,
some specimens vary in roundness, flatness, development of the ventral muscleplate, and sharpness of the lateral groove. Comparison of many specimens of this genus preserved in alcohol with those preserved as dry specimens shows that those preserved in alcohol frequently develop a coppery sheen due to chemical change. Theiler has made similar observations in this respect. The obscurity of the color pattern and its overlay with a basic color in some specimens in any extensive collection of amblyommas from even a single host is taken for granted by most students. Using the above mentioned criteria, proposed by Schulze, large collections of A. # and A. lepidum from single herds of cattle have been examined. It £a that each collection contains no less than four "species" and up to seven "species".
Comparison of Sudan specimens with others from various parts of Africa and of the type specimens of A. nuttalli in British Museum (Natural History) reveals no significant differences to obtain between any of them.
It is for these reasons that it has been proposed (Hoogstraal 1954B) to consider A, werneri werneri Schulze, 1932(A), as a synonym of A. nuttalli Tönitz, •
It is also of some interest to consider the status of A.
werneri poematium Schulze, 1932, described on the basis of two
es from a young rhinoceros, at the Amsterdam zoological gardens, from East Africa. This subspecies was distinguished by "a wonderful metallic, copper, partly greenish gloss (with) brown elements of the conscutum bordered in copper", in one of the two specimens, but in the other "the structure producing the metallic coloration was in greatest part destroyed, only in a few places did the greenish coppery sheen show up". The size of these specimens was also larger than that of the subspecies werneri.
I have seen a male specimen taken from a Somali tortoise
(#17691, Rocky Mountain Laboratory, Hamilton, determined as A. werneri by Dr. E. Stella). This tick answers the description of A. W. poematium but has a somewhat rugose scutum suggestive of injury during molting or during an immature stage. The specimen resembles a teneral individual, i.e. one that has been preserved shortly after molting while still bloated and before the colors are fast.
Santos Dias (1954G) opines that (1) A. poematium is a separate species, (2) A. schlottkei Schulze, 1932, might be a synonym, and (3) A. faiai Santos Dias, I951, definitely is a synonym. The specificity of A. poematium is hardly convincing on the basis of descriptions and illustrations, though there is a possibility that comparison of specimens may provide yet unmentioned clues to separate this morphologically from A. nuttalli. Breeding experiments are also indicated.
A. nuttalli is similar to A. marmoreum in characters mentioned under that species, except for the following: Males: Size is smaller, always less than 6.0 mm. long. Pale ornamentation of the scutum is somewhat variable, but all specimens are like the one illustrated in that the dark areas are less extensive and more broadly separated from each other by light areas than they are in A. marmoreum.
Females: This sex is also smaller than that of A. marmoreum (body approximately 7.0 mm. long, 5.5 mm. wide; scutum about 3.2 mm. long, 3.3 mm. wide); the central pale scutal ornamentation tapers to a narrow point posteriorly and is therefore very distinctive.