Page images
PDF
EPUB

Unknown.

DISEASE RELATIONS

IDENTIFICATION

With so few specimens extant, the variability of R. bequaerti cannot be determined.

Males. This sex is easily recognizable by complete absence of lateral grooves that are replaced by a line of large punctations bounding the raised lateral ridge. Medium size scutal punctations are arranged linearly like those of R. simus but are interspersed with numerous fine interstitial punctations. The posteromedian groove is long and narrow, the paramedian grooves are curved and wider. The cervical pits are short, deep, and punctiform. The adanal shields are L shaped with a heavy, broad base, convex interno anterior margin, and other margins straight with rounded junctures. Coxa I has a small but distinct dorsal projection. The original description states that the spurs of coxa I are "strikingly short but the illustration accompanying the des cription hardly verifies this statement. Color is reddish-brown.

Females. The scutum is approximately as wide as long and its posterior margin is abruptly rounded. Lateral grooves are greatly reduced, being restricted to the anterior half of the scutum; bordering these grooves the lateral ridges rise sharply. Cervical pits are wide and deep; cervical grooves reach almost to the posterior scutal margin. Punctations are large and widely scattered, interstitial punctations are stronger than in the male. The basis capituli is twice as wide as long, with rightangled lat. eral angles and short, rounded cornua; large porose areas are circular or subcircular and spaced apart from each other by less than their own diameter (in R. s. simus, these are small, circular, and spaced far apart).

A small dorsal process of coxa I is present on the Sudan specimen, though this process is stated to be absent on the type fe male. Eyes of the Sudan specimen are situated on the scutal mar gin, dark amber color, elongately oval, very slightly convex, and delimited by a shallow groove along the internal border. The Sudan specimen was identified by Dr. G. Theiler.

[graphic][subsumed][subsumed][subsumed][subsumed][subsumed]

Figures 253 and 254, o, dorsal and ventral views Figures 255 and 256, o, dorsal and ventral views

RIIPICEPHALUS COMPOSITUS
Sudan Specimens

PLATE LXXII

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small]

These specimens, from the east and west banks of Equatoria Province, are the first of R. compositus from known localities in the Sudan. Although the Kheirallah (spelled Hierallah on the label) specimens were collected in 1911 by H. H. King, they had remained unidentified in Sudan Government collections. For further comments on these specimens, see BIOLOGY below.

DISTRIBUTION IN THE SUDAN

The type locality given by Neumann (1897) for R. compositus is Khartoum. It is obviously impossible that this tick has been established in this desert environment in recent times. Un fortunately, the source of specimens provided Neumann was fre quently incorrect and his acceptance of collectors' information has subsequently led to numerous misconceptions before knowledge of the species concerned became detailed enough to recognize these errors. It is hardly likely, in the troubled and harassed times when the type specimens were reputed to have been collected at Khartoum, that cattle were being imported there in any numbers from areas where this tick is likely to occur. It is possible, but not very probable, that the collector merely lumped the vast poorly-explored northeastern African area of his day under the heading Khartoum. The normal occurrence of R. compositus out side of Equatoria Province in the Sudan is hardly to be expected, and even in this Province it is probably restricted to the rather few highland outcrops and their vicinity.

DISTRIBUTION

R. compositus, as shown by Theiler, Walker, and Wiley (1956), is a locally common East African highland parasite with scattered populations in the highlands of Central Africa and of eastern

West Africa. Literature before 1933 refers to it as R. compositus, from 1933 onwards mostly as R. ayeri. See REMARKS below and Theiler, Walker, and Wiley (1956).

WEST AFRICA: NIGERIA (Mettam 1950. Unsworth 1949,1952.

Gambles 1951. Theiler, Walker, and Wiley 1956).

CENTRAL AFRICA: CAMEROONS (Unsworth 1952. Theiler, Walker, and Wiley 1956). BELGIAN CONGO and RUANDA URUNDI (Bequaert 1930A, B,1931. Theiler remarks in Santos Dias 1949D, p. 170. Hoogstraal 1954C. Theiler and Robinson 1954. Van Vaerenbergh 1954. Theiler, Walker, and Wiley 1956. It seems likely that the "R. capensis" of Schoenaers 1951A,B, refers to R. compositus).

EAST AFRICA: SUDAN (Neumann 1897, see DISTRIBUTION IN THE SUDAN above. Hoogstraal 1954B. Theiler, Walker, and Wiley 1956).

KENYA (Lewis 1933,1934. Theiler, Walker, and Wiley 1956). UGANDA (Wilson 1948,1950A,1952,1953. Theiler, Walker, and Wiley 1956). TANGANYIKA (Dönitz 1905. Neumann 1911. Theiler, Walker, and Wiley 1956. J. B. Walker, unpublished; see HOSTS below).

SOUTHERN AFRICA: NORTHERN RHODESIA (Le Roux 1947. Theiler remarks in Santos Dias 1949D, p. 170. Matthysse 1954. Theiler, and Robinson 1954. Theiler, Walker, and Wiley 1956). NYASALAND (Theiler remarks in Santos Dias 19490. Wilson 1950B. Theiler, Walker, and Wiley 1956). MOZAMBIQUE (Santos Dias 1949A,E,F, 1952,1953B,1954A. Theiler, Walker, and Wiley 1956).

HOSTS

The buffalo appears to be the preferred host of R. compositus and other larger game animals to be second choice. In some areas, this tick transfers to cattle but, as shown by Theiler, Walker, and Wiley (1956), it is not known to do so in Kenya. In Northern

Rhodesia, Matthysse (1954), however, recorded this tick only from cattle. A single incidence of parasitism on man has been reported. Hosts of the immature stages in nature are unknown.

Man (Hoogstraal 1954C).

Domestic animals: Cattle (Neumann 1904,1911, Wilson 1948, 1950A,B, Santos Dias 1949A,F,1953B. Matthysse 1954. Van Vaeren bergh 1954, Theiler, Walker, and Wiley 1956). Dog (Dönitz 1905, Theiler, Walker, and Wiley 1956).

Wild animals: Buffalo (Lewis 1933, Wilson 1948,1950B, Santos Dias 1953B, Theiler, Walker, and Wiley 1956). Rhinoceros (Lewis 1933, Theiler, Walker, and Wiley 1956). Roan antelope (Lewis 1934). Eland (Theiler, Walker, and Wiley 1956). Lichtenstein's hartebeest (Santos Dias 1952H,1953B). Sitatunga (J. B. Walker, Tanganyika; unpublished). Lion (Lewis 1933, Wilson 1950B, Theiler, Walker, and Wiley 1956). Cheetah (Wilson 1950B). "Game" (Wilson 1950A). Bushpig (Santos Dias 1953B). Warthog (Bequaert 1930A,1931, Santos Dias 1953B).

BIOLOGY

Life History

Details of the life history under laboratory conditions will be presented by Theiler, Walker, and Wiley (1956). Observations on the seasonal occurrence of various stages are presented below.

Ecology

R. compositus (= R. ayeri) is included in the ecological zone referred to as the R. appendiculatus A. variegatum association (cf. page 274), but restricted to highland forests where it may occur locally together with R. kochi (= R. jeanneli).

It is likely that R. compositus and R. kochi were once more isolated than they presently are and that they now occupy in part

« PreviousContinue »