The Influence of Interspecific Competition and Host Preference on the Phylogeography of Two African Ixodid Tick Species

A comparative phylogeographic study on two economically important African tick species, Amblyomma hebraeum and Hyalomma rufipes was performed to test the influence of host specificity and host movement on dispersion. Pairwise AMOVA analyses of 277 mtDNA COI sequences supported significant population differentiation among the majority of sampling sites. The geographic mitochondrial structure was not supported by nuclear ITS-2 sequencing, probably attributed to a recent divergence. The three-host generalist, A. hebraeum, showed less mtDNA geographic structure, and a lower level of genetic diversity, while the more host-specific H. rufipes displayed higher levels of population differentiation and two distinct mtDNA assemblages (one predominantly confined to South Africa/Namibia and the other to Mozambique and East Africa). A zone of overlap is present in southern Mozambique. A mechanistic climate model suggests that climate alone cannot be responsible for the disruption in female gene flow. Our findings furthermore suggest that female gene dispersal of ticks is more dependent on the presence of juvenile hosts in the environment than on the ability of adult hosts to disperse across the landscape. Documented interspecific competition between the juvenile stages of H. rufipes and H. truncatum is implicated as a contributing factor towards disrupting gene flow between the two southern African H. rufipes genetic assemblages

Effects of tectonics and large scale climatic changes on the evolutionary history of Hyalomma ticks

Corrigendum to Effects of tectonics and large scale climatic changes on the evolutionary history of Hyalomma ticks Molecular Phylogenetics and Evolution (2017) 114:153-165. Sands AF, Apanaskevich DA, Matthee S, Horak IG, Harrison A, Karim S, Mohammad MK, Mumcuoglu KY, Rajakaruna RS, Santos-Silva MM, Kamani J, Matthee CA. Mol Phylogenet Evol. 2018 Mar;120:390. doi: 10.1016/j.ympev.2018.01.010. Disponível em: https://www.sciencedirect.com/science/article/pii/S1055790318300307?via%3DihubHyalomma Koch, 1844 are ixodid ticks that infest mammals, birds and reptiles, to which 27 recognized species occur across the Afrotropical, Palearctic and Oriental regions. Despite their medical and veterinary importance, the evolutionary history of the group is enigmatic. To investigate various taxonomic hypotheses based on morphology, and also some of the mechanisms involved in the diversification of the genus, we sequenced and analysed data derived from two mtDNA fragments, three nuclear DNA genes and 47 morphological characters. Bayesian and Parsimony analyses based on the combined data (2242 characters for 84 taxa) provided maximum resolution and strongly supported the monophyly of Hyalomma and the subgenus Euhyalomma Filippova, 1984 (including H. punt Hoogstraal, Kaiser and Pedersen, 1969). A predicted close evolutionary association was found between morphologically similar H. dromedarii Koch, 1844, H. somalicum Tonelli Rondelli, 1935, H. impeltatum Schulze and Schlottke, 1929 and H. punt, and together they form a sister lineage to H. asiaticum Schulze and Schlottke, 1929, H. schulzei Olenev, 1931 and H. scupense Schulze, 1919. Congruent with morphological suggestions, H. anatolicum Koch, 1844, H. excavatum Koch, 1844 and H. lusitanicum Koch, 1844 form a clade and so also H. glabrum Delpy, 1949, H. marginatum Koch, 1844, H. turanicum Pomerantzev, 1946 and H. rufipes Koch, 1844. Wide scale continental sampling revealed cryptic divergences within African H. truncatum Koch, 1844 and H. rufipes and suggested that the taxonomy of these lineages is in need of a revision. The most basal lineages in Hyalomma represent taxa currently confined to Eurasia and molecular clock estimates suggest that members of the genus started to diverge approximately 36.25 million years ago (Mya). The early diversification event coincides well with the collision of the Indian and Eurasian Plates, an event that was also characterized by large scale faunal turnover in the region. Using S-Diva, we also propose that the closure of the Tethyan seaway allowed for the genus to first enter Africa approximately 17.73 Mya. In concert, our data supports the notion that tectonic events and large scale global changes in the environment contributed significantly to produce the rich species diversity currently found in the genus Hyalomma.The National Research Foundation (NRF) is thanked for their financial support of the study and the Faculty of Science (University of Stellenbosch) for a scholarship provided to AFS.info:eu-repo/semantics/publishedVersio

Redescription of <i>Haemaphysalis (Rhipistoma) elliptica</i> (Koch, 1844), an old taxon of the <i>Haemaphysalis (Rhipistoma) leachi</i> group from East and southern Africa, and of <i>Haemaphysalis (Rhipistoma) leachi</i> (Audouin, 1826) (Ixodida, Ixodidae

Koch (1844) originally described only the male of Haemaphysalis (Rhipistoma) elliptica (Koch, 1844), which he named Rhipistoma ellipticum. For the past century, however, this name has been considered a junior synonym of Haemaphysalis (Rhipistoma) leachi (Audouin, 1826), or a nomen nudum. We redescribe here the male and larva of H. (R.) elliptica and describe the female and nymph for the first time. Our redescription is based on the male holotype, plus numerous specimens from southern and East Africa. The adults of this tick parasitize domestic and wild carnivores, and the immature stages infest rodents in these regions. For comparative purposes redescriptions of all parasitic stages of H. (R.) leachi are provided. It parasitizes the same hosts as H. (R.) elliptica in Egypt, and in northeastern, Central, West and East Africa

A new species of Ixodes (Acari: Ixodidae) from South African mammals

A new tick species belonging to the African subgenus Afrixodes Morel, 1966, namely, Ixodes (Afrixodes) fynbosensis n. sp., is described. The female of I. fynbosensis is easily differentiated from the other African Ixodes species by a large, tapering triangular ventrolateral spur on palpal segment I. Nymph and larva of I. fynbosensis can be distinguished from those of other members of Afrixodes by a combination of the following characters: pointed hypostome, long auriculae, long and acute ventrolateral projections of basis capituli of nymph, only 2 pairs of central dorsal setae, and a straight posterior margin of scutum of the larva. Cytochrome oxidase I mtDNA sequence comparisons between I. fynbosensis and 10 other Ixodes Latreille, 1795, species support the recognition of this taxon as genetically distinct (>13% corrected sequence divergences separate it from the remainder of the 10 recognized species used in this study), and preliminary phylogenetic analyses reveal that this taxon is most closely related to the southern African Ixodes pilosus Koch, 1844, and Ixodes rubicundus Neumann, 1904. Ixodes fynbosensis is known only from South Africa, where females have been collected from a domestic dog and a rodent, Rhabdomys pumilio (Sparrman), and nymphs and larvae have been collected from R. pumilio and unidentified shrews belonging to the Soricidae. Sequences generated for both nymphs and adult individuals were identical, confirming the correlation between the described life stages. © American Society of Parasitologists 2011.Articl

Diversity and distribution of tick species (Acari: Ixodidae) associated with human otoacariasis and socio-ecological risk factors of tick infestations in Sri Lanka

Tick infestation in humans is a major public health concern. The diversity and distribution of tick species associated with human otoacariasis was studied in five districts: Anuradhapura, Kandy, Kurunegala, Nuwara Eliya and Ratnapura in the main agro-climatic zones of Sri Lanka. Ticks from patients attending the ear, nose and throat clinics of the General Hospitals were collected during a 3 year period. In total 426 ticks were collected. Most human otoacariasis cases were reported from Kandy (33.8 %) and the fewest from Nuwara Eliya (8.2 %). Of the five tick species identified, nymphs of Dermacentor auratus constituted 90.6 % of the collection. Rhipicephalus sanguineus, Hyalomma isaaci, Haemaphysalis bispinosa and Otobius megnini were found rarely infesting humans possibly as an accidental host; H. bispinosa and O. megnini in the human ear canal were first time records in Sri Lanka. Females and children under 10 years were identified as risk groups of human otoacariasis. Subsequently, a field study was carried out to determine socio-ecological risk factors of human tick infestations in the five districts. Based on hospital data, eight villages with high prevalence of otoacariasis were selected from each district. A total 40 villages were visited and 1674 household members were interviewed. Involvement in outdoor activities, presence of wild animals around the house, location of the house in close proximity to a forest and occupation were identified as major risk factors