HAEMAPHY SALIS HOUYI Nuttall and Warburton, 1915. (Figures 140 to 143) THE WEST AFRICAN GROUND SQUIRREL TICK L NO EQUATORIA PROVINCE RECORDS Euxerus erythropus leucoumbrinus Dec DISTRIBUTION IN THE SUDAN Bahr El Ghazal: All from Galual-Nyang Forest, from five specimens of Euxerus erythropus subspp., in 1953, by H. Hoogstraal: 600, 19, 17 February; 400, 500, 4 nymphs, 19 February; 2007, 16 February. Upper Nile: Bor, ex "Xerus rutilus", 200, 21 May 1909, H. H. King legit (S.G.C.). (This host name is a misidentification for Euxerus erythropus subspp.). - Blue Nile: As o of H. calcarata: Roseires, from ground squirrel (Neumann 1910A); also records two do that are probably H. houyi; Ch. Alluaud legit; cf. Hoogstraal (1955D). Kamisa, Dinder River, lo, lo, W. P. Lowe legit EM (NH)7. DISTRIBUTION H. houyi is a ground squirrel parasite extending in a belt across the widest part of Africa from the Atlantic Ocean through French West Africa, Cameroons, the Sudan, and Uganda to the north western corner of Kenya, west of the Rift Valley. It is closely related to H. calcarata that parasitizes a different genus of ground squirrels in East Africa east of the Rift Valley (Hoogstraal 1955D). See also HOSTS and BIOLOGY below. WEST AFRICA: FRENCH WEST AFRICA (Rousselot 1951,1953B. Hoogstraal 1955D. Villiers 1955). CENTRAL AFRICA: FRENCH EQUATORIAL AFRICA (Bate, "New Cameroons" (Nuttall and Warburton 1915. Hoogstraal 1955D). EAST AFRICA: SUDAN (As of H. calcarata: As H. houyi: Hoogstraal 19548,1955D). UGANDA and KENYA (Hoogstraal 1955D). Neumann 1910A. HOSTS Ground squirrels, Euxerus erythropus subspp. (All authors). King's specimen from "Xerus rutilus" at Bor (SGC) is based on a misidentification of the host. E. erythropus is the common ground squirrel of West Africa, and of Northcentral and East Africa west of the Rift Valley. East of the Rift Valley it is replaced by Xerus rutilus subspp., parasitized by H. calcarata Neumann, 1902*. In Kenya, Xerus is confined to hot lowlands and Euxerus to higher, arable mountains from 2000 feet to 6000 feet elevation, but mostly above 3000 feet. If, as now seems apparent, it is true that these two ticks are so host specific, this would seem to be a bolstering argument against lumping these two squirrel genera in one genus, as some mammalogists advocate (Hoogstraal 1955D). BIOLOGY Aside from the fact that all stages may be found on a single ground squirrel, little is known concerning the biology of H. houyi. This tick and its host inhabit savannah country with few or scattered trees, and upland grasslands. Along the southern border of the squirrel's range it extends into forested districts, but only in tongues of grassland with scattered trees between thicker forest. As already stated under HOSTS, in Kenya, where the two host genera and the two related tick species occur near each other, the host of H. houyi is confined mostly to arable uplands and that of H. calcarata inhabits warmer and more arid lowlands. *The record of H. calcarata from Dahomey (Villiers 1955) undoubtedly is based on misidentification. In the Galual Nyang forest area of Bahr El Ghazal, each of five host specimens examined was infested. In Torit District of Equatoria, a third of the 27 hosts examined yielded specimens of H. houyi. DISEASE RELATIONS Unstudied but potentially important. IDENTIFICATION The following characters easily distinguish males among the Sudan haemaphy salid fauna: strong ventral spur on trochanter I; all coxae with distinct spurs; tarsi short, robust, and abruptly tapered; palpi widely expanded basally, without a developed dorsal spur basally, with basal spur ventrally and spur from segment 3 ventrally; basis capituli strongly diverging anteriorly and with moderate cornua; dentition 4/4; scutum with long, deep lateral grooves enclosing first festoon, and few, scattered, shallow, inconspicuous punctations of mixed sizes; size ranges from an overall length of 1.71 mm. to 2.15 mm. and width of 0.99 mm. to 1.20 mm. Females are also easily recognized by the raised spurlike, non-projecting ventral ridge of trochanter I, coxae and tarsi almost exactly like those of male; palpi essentially like those of male but larger and more elongate, basis capituli short, wide, and with prominent cornua and anteriorly diverging lateral margins; dentition 4/4; scutum only very slightly longer than wide and broadly rounded posteriorly, with few, shallow, scattered punctations of various sizes mostly on anterior half. The size is somewhat greater than that of males. |