Notes on African Haemaphysalis Ticks. X. H. (Kaiseriana) aciculifer Warburton and H. (K.) rugosa Santos Dias, the African Representatives of the Spinigera Subgroup (Ixodoidea: Ixodidae)

Abstract

Haemaphysalis (Kaiseriana) aciculifer Warburton and H. (K.) rugosa Santos Dias have been confused in much literature on African ticks. The adult and immature stages of aciculifer are redescribed. The male of rugosa is described and the female redescribed; rugosa was previously known only from the holotype female. Hosts of adults are chiefly antelopes, occasionally hares, buffalo, and carnivores, and also domestic cattle, sheep, and goats. Immature aciculifer parasitize hedgehogs, rodents, small carnivores, and (single record) birds. Ecological preference appears to be for relatively more humid wooded riparian and valley biotopes of the savanna belt. The distribution of aciculifer is from Cameroun eastward to Ethiopia and southward to Rhodesia (introduced into South Africa); of rugosa from Ghana and Senegal to Uganda and western and southern Sudan. These species, together with H. (K.) parmata Neumann, are the only representatives in the Ethiopian Faunal Region of tlhe subgenus Kaiseriana Santos Dias, 29 other members of which occur in the Oriental, Australian, and northeastern Palearctic Regions. Certain structural modifications representing a unique phylogenetic trend in the H. (K.) cornigera group of Asia and New Guinea are typical in aciculifer but remarkably reversed in rugosa. A key is provided to differentiate between species of the spinigera subgroup (aciculifer, rugosa, spinigera, novaeguineae) of the H. (K.) cornigera group. Recently we showed the close relationship between the Asian Haemaphysalis (Rhipistoma) canestrinii (Supino) and the medically important African H. (R.) leachi Audouin (Hoogstraal, 1971). The present study reveals a comparable relationship between H. (Kaiseriana) aciculifer Warburton (Figs. 1-35) and H. (K.) rugosa Santos Dias (Figs. 36-64) of tropical Africa, the medically important H. (K.) spinigera Neumann of the Indian Subregion, and H. (K.) novaeguineae Hirst of New Guinea. Among the 150 species now known in the genus Haemaphysalis, 20 (some unpublished) occur in the Ethiopian Faunal Region, where the only representatives of the subgenus Kaiseriana Santos Dias are H. (K.) aciculifer, H. (K.) rugosa, and H. (K.) parmata Neumann. The subgenus Kaiseriana contains Received for publication 9 May 1972. * From Research Project MF12.524.009-3010B, Bureau of Medicine and Surgery, Department of the Navy, Washington, D. C. The opinions and assertions contained herein are the private ones of the authors and are not to be construed as official or as reflecting the views of the Department of the Navy or of the naval service at large. This investigation was supported in part by Agreement 03-005-1 between the NIAID (NIH) and NAMRU-3. 29 other described species in the Oriental, Australian, and northeastern Palearctic Regions. Of the 20 Ethiopian Region haemaphysalids, 15 are in the subgenus Rhipistoma Koch, one (H. silacea Robinson) in the subgenus Haemaphysalis, one (H. hoodi Warburton and Nuttall) in an undescribed subgenus, and three in Kaiseriana. This study is part of an effort to contribute to knowledge of the historic and contemporary zoogeographic distribution of Haemaphysalis tick groups in different faunal regions and to an understanding of the influence of these phenomena on the presence and distribution of tickborne pathogens (Hoogstraal, 1966, 1967, 1972; Casals et al., 1970). H. (K.) rugosa, which was previously known only from the holotype specimen (Figs. 5664), is obviously closely related to H. (K.) aciculifer. However, aciculifer is structurally typical of the H. (K.) cornigera group but rugosa exhibits a reversal of the phylogenetic trend within this group toward exceptional broadening of the male palpal segment 3 and reduction of the posterodorsal spur. This broadening results in a great degree of sexual dimorphism in all species of the group except rugosa. Palpal segment 3 of rugosa is unique