Carleton M. Clifford

Clarification of the Rhipicephalus sanguineus group (Acari, Ixodoidea, Ixodidae). II. R. sanguineus (Latreille, 1806) and related species

AbstractIn this, our second study on the biosystematics of the Rhipicephalus sanguineus group, we consider an additional five species found in the Afrotropical region, namely R. sanguineus, R. camicasi, R. guilhoni, R. moucheti and R. bergeoni.Cross-breeding experiments have shown that R. sanguineus (Latreille, 1806) sensu stricto is genetically distinct from R. camicasi Morel, Mouchet & Rodhain, 1976. Further cross-breeding trials confirmed that R. camicasi also occurs in Saudi Arabia: a field strain from this country was more productive than a laboratory-reared strain from Egypt. R. sanguineus, which parasitises mainly dogs, probably occurs throughout the Afrotropical region. R. camicasi parasitises both large and small domestic ruminants and is restricted to the arid and semi-arid lowlands of northeastern Africa and the Arabian peninsula. The larva, nymph, male and female of these two last named species are described with the aid of scanning electron micrographs (SEMs).The two western African species, R. guilhoni Morel & Vassiliades, 1963 and R. moucheti Morel, 1964, are accepted as valid members of the R. sanguineus group, but we have little material available for critical study. The male and female of R. guilhoni are briefly redescribed with the aid of SEMs. R. bergeoni Morel & Balis, 1976 occurs predominantly on cattle in the wetter highlands and subhighlands of Ethiopia and Sudan. The male and female are briefly described. Current morphological and ecological data suggest that the inclusion of this species in the R. sanguineus group is questionable.

Clarification of the Rhipicephalus sanguineus group (Acari, Ixodoidea, Ixodidae). I. R. sulcatus Neumann, 1908 and R. turanicus Pomerantsev, 1936

AbstractFor many years the biosystematic status of several species in the Rhipicephalus sanguineus group has been confused, with the result that they have often been misidentified. Over the years some 18 of these species have been synonymised with R. sanguineus (Latreille, 1806) itself. More recently four new species in the group have been described: R. guilhoni Morel & Vassiliades, 1963; R. moucheti Morel, 1964; R. bergeoni Morel & Balis, 1976; and R. camicasi Morel, Mouchet & Rodhain, 1976.The literature on this group is critically reviewed and the main systematic problems analysed. R. sulcatus Neumann, 1908 and R. turanicus Pomerantsev, 1936 are two species that were confused both morphologically and ecologically. This has resulted in erroneous conclusions regarding their host relationships and distributions. Integrated biological, morphological and ecological studies on these two species have been conducted. Cross-breeding experiments have proved that both are distinct taxonomic entities. Interbreedings between African and Cypriot strains of R. turanicus demonstrated marked heterosis.A scanning electron microscope was used to determine the main diagnostic morphological differences between the larvae, nymphae and adults of R. sulcatus and R. turanicus, and the morphological similarities between African and Cypriot strains of R. turanicus. Rhipicephalus sulcatus occurs widely in the Afrotropical region in wetter ecological habitats and most frequently parasitises hares, dogs and jackals. R. turanicus occurs more-or-less throughout the Afrotropical region in a wide range of climatic biotopes, as well as in parts of southern Europe, Arabia and Asia, and is most abundant in the late rainy/early dry seasons. It occurs on a wide range of domesticated and wildlife hosts, including ground-feeding birds.

The Ornithodoros (Alectorobius) capensis group (Acarina: Ixodoidea: Argasidae) of the palearctic and oriental regions. O. (A.) maritimus: identity, marine bird hosts, virus infections, and distribution in western Europe and northwestern Africa.

In 1967, Vermeil and Marguet described Ornithodoros coniceps maritimus from larvae reared from larvae taken from marine birds on Dumet Island (Atlantic Ocean), Basse Bretagne, France. We collected O. (A.) coniceps Canestrini, 1890, from the type locality (Venice, Italy) and determined that the taxons coniceps and maritimus each require full species status. We selected a lectotype and paralectotypes for the taxon maritimus from the original Dumet Island material. The larva of maritimus is redescribed and the nymph, male, and female are described for the first time. Collection data are recorded from Dumet and other islands off France, Aegimures Islands off Tunisia, Puffin Island off northern Wales, and Great Saltee Island off Ireland. This tick infests nesting colonies of the common tern, roseate tern, sandwich tern, herring gull (northern and Mediterranean races), common cormorant, shag, razorbill, common murre, black-legged kittiwake, and probably other marine birds nesting nearby. Adults and nymphs (tentatively identified as maritimus but lacking associated larvae for full confirmation) were taken near nests of the little egret in Lake Tunis, Tunisia. Soldado virus was isolated from Puffin Island tick samples and a Soldado-like virus from Great Saltee Island tick samples. An experimental study of West Nile virus in the Tunisian tick population is reviewed. The birds species associated with maritimus in each collecting locality, and their nesting and resting habits and migration patterns in relation to tick and arbovirus survival and distribution, will be reported in the following paper in this series.

Effects of limb disability on lousiness in mice III. Gross aspects of acquired resistance

Abstract Studies of louse populations on partially disabled mice kept individually to prevent mutual grooming have demonstrated that after initial exposure to the parasite, subsequent populations were limited because of development of acquired resistance by the mice. During these experiments it was established that a long period of intensive exposure is required for full development of the resistant state. Further, based on a limited period of observation, the inhibitory function appears to be limited to the exposed site rather than generalized over the entire body. Although detritus that accumulates in a region heavily infested with lice was not a major factor in the resistance to reinfestation that was noted, it could not be eliminated as a minor one. The successful feeding of larval ixodid ticks on louse-resistant mice in a single experiment indicated that the resistance is probably specific for lice.

Effects of limb disability on lousiness in mice. II. Intersex grooming relationships

Abstract Mice that are handicapped as a result of hindlimb disability or amputation develop very large louse burdens when kept separately, but when kept in groups mutual grooming frees them of lice. The most rapid reduction of established louse populations occurred when male mice were placed with female mice. The most efficient grooming took place when one member of a pair was normal and uninfested. Compatibility influenced the grooming reaction, especially in male twosomes. Litter mates kept together were most uniform in reciprocal grooming reactions. Mutual grooming was a life-saving activity among animals overwhelmed by lice as a result of artificially induced postinfectious paralysis. It is postulated as a factor of importance in the parasite-host relationship in wild rodents.

Observations on the subgenus Argas (Ixodoidea: argasidae: Argas). 17. Argas (A.) polonicus sp. n. parasitizing domestic pigeons in Krakow, Poland.

Argas (A.) polonicus sp. n. is described from males, females, nymphs, and larvae from the steeple tower of St. Marys Church, Karkow, Poland, where it feeds on domestic rock pigeons, Columba livia Gmelin. This species is related to the widely distributed Eurasian A. (A.) vulgaris Filippova and to certain other species of the eastern area of the Palearctic Faunal Region; it differs distinctly from A. (A.) reflexus (Fabricius) of western Europe. Comparative study under the light microscope. and especially under the scanning electron microscope, reveals numerous structural differences in adult and immature stages of these species, chiefly in the Hallers organ roof of each stage, adult body shape and integumental formations, dental formulae, and setal lengths and numbers on the larval dorsum.

Polyplax serrata: Histopathology of the skin of louse-infested mice

The sequence of changes in the inflammatory reaction in the skins of mice infested with the louse, Polyplax serrata (Burmeister) (Anoplura), was examined in detail throughout 12 weeks of infestation. The reaction was manifest in 2 phases. The first phase, lasting for 4 weeks after initial infestation, was characterized by an increase (followed by a decrease) in epidermal thickness, invasive neutrophils, eosinophils, and lymphocytes. After an initial increase in the first week (hyperemia), the numbers of vessels containing blood decreased steadily until the fifth week and remained low until the twelfth week. Arteriolar vasoconstriction was seen regularly after the second week. The second phase, lasting for the next 8 weeks, was characterized by another increase (followed by a decrease) in epidermal thickness, tissue lymphocytes, and monocytes. A sustained increase in mast cell numbers occurred, accompanied by degranulation of these cells. Fibroblast proliferation was also increased. The data indicate that the histopathologic reaction of mice to sucking lice is basically similar to that shown in sheep infested with the sheep ked shown earlier. There is a suggestion that the skin changes represent the basic protective mechanism necessary for acquired host resistance both for the ked-sheep and for systems involving the Anoplura.

Isolation of a Soldado-like virus (Hughes group) fromOrnithodorus maritimus ticks in Ireland

Three isolations of a virus of the Hughes group were obtained from seabird ectoparasites,Ornithodoros (Alectorobius) maritimus, on Great Saltee Island, Ireland. The agent is closely related to Soldado virus, originally obtained from related ticks near Trinidad, West Indies, and represents the second recorded tickborne arbovirus in Ireland.

THE ORNITHODOROS (ALECTOROBIUS) CAPENSIS GROUP (ACARINA: IXODOIDEA: ARGASIDAE) OF THE PALEARCTIC AND ORIENTAL REGIONS. O. (A.) CONICEPS IDENTITY, BIRD AND MAMMAL HOSTS, VIRUS INFECTIONS, AND DISTRIBUTION IN EUROPE, AFRICA, AND ASIA*

Ornithodoros (Alectorobius) coniceps (Canestrini 1890), which was briefly described from adult specimens from St. Marks Cathedral, Venice, Italy, has been a confusing taxon. We redescribe and illustrate the adult and immature stages from St. Marks Cathedral (topotypes) and elsewhere, list criteria to distinguish this species from others in the O. (A.) capensis complex, and provide data for 36 collections, chiefly from nest sites of wild and domestic pigeons in humid, rocky situations, and from a nest of the pallid swift, in Italy, France, Egypt, Kenya, Israel, Jordan, Afghanistan, Ukrainia, and Turkmenia. Other collections of small-sized adults and nymphs, lacking larvae, from pigeon, swallow, and swift nest in Nepal, India, and Sri Lanka, are tentatively assigned to this taxon. This is the only member of the O. (A.) capensis group not associated with marine or wading birds. Humans bitten by O. (A.) coniceps in buildings or caves may suffer from pain, edema, chills, and fever. BAku virus (Reoviridae) has been isolated from this tick in Uzbekistan, but most reports of other viruses and infectious agents are clouded by probable misidentification of O. (A.) maritimus as O. (A. coniceps. Published data on the life cycle and dynamics are reviewed briefly. Previously, this tick has not been reported from the Ethiopian Faunal Region (Kenya).

Clarification of the status of Rhipicephalus tricuspis Dönitz, 1906 and Rhipicephalus lunulatus Neumann, 1907 (Ixodoidea, Ixodidae)

AbstractThe systematic status of Rhipicephalus species whose males have tricuspid adanal plates has been confused for many years. Some authors have regarded Rhipicephalus tricuspis Dönitz, 1906 as the only valid entity with this morphological character and synonymized both Rhipicephalus lunulatus Neumann, 1907 and Rhipicephalus glyphis Dönitz, 1910 with it. Others, however, have always maintained that R. tricuspis and R. lunulatus (syn. R. glyphis) are separate species. Detailed comparative studies, including scanning electron microscopy, of laboratory-reared series as well as numerous field collections of these ticks have now confirmed that the latter view is correct. In addition, a third species, designated here as a ‘Rhipicephalus sp. near tricuspis’, has been identified as a member of this group.All stages of R. tricuspis and R. lunulatus are herein redescribed and illustrated by means of scanning electron micrographs. Their life cycles in the laboratory, hosts, distribution and disease relationships are discussed and their differentiation is described with the aid of line drawings. Rhipicephalus tricuspis has been recorded primarily in southern Africa, but also in Zambia and western Zaire, in various types of dry woodland. Its adults are most commonly parasitic on relatively small mammals such as hares, spring hares, jackals and small antelopes. R. lunulatus is much more widespread in the Afrotropical region, most commonly in different types of woodland but also in a variety of other habitats. Its adults parasitize a very wide range of hosts including domestic animals (especially cattle and dogs), the African buffalo, many different antelopes (especially the larger species) and wild pigs. The Rhipicephalus sp. near tricuspis occurs in eastern and parts of central Africa, where its distribution often overlaps with that of R. lunulatus.