TAXONOMIC STATUS OF LAELAPS PETRISCHEVAE ZEMSKAYA ET LANGE, 1979 (ACARI: PARASITIFORMES: GAMASINA)

Laelaps petrischevae Zemskaya et Lange, 1979 was described ex Microtus voles from the northern parts of Western and Middle Siberia. However, the species has not been mentioned later in taxonomic and faunistic papers dealing with the ectoparasitic gamasid mites of Siberia. Examination of newly collected laelapid mites from the Yamal Peninsula as well as the comparison with the published data led to conclusion that L. petrischevae Zemskaya et Lange, 1979 (syn. n.) is a junior synonym of L. alaskensis Grant, 1947. Key for identification of females of the Laelaps species inhabiting the northern regions of Western and Middle Siberia is given

An annotated catalogue of the gamasid mites associated with small mammals in Asiatic Russia. The family Laelapidae s. str. (Acari: Mesostigmata: Gamasina)

Vinarski, Maxim V., Korallo-Vinarskaya, Natalia P. (2016): An annotated catalogue of the gamasid mites associated with small mammals in Asiatic Russia. The family Laelapidae s. str. (Acari: Mesostigmata: Gamasina). Zootaxa 4111 (3): 223-245, DOI: http://doi.org/10.11646/zootaxa.4111.3.

An annotated catalogue of the gamasid mites associated with small mammals in Asiatic Russia. The family Hirstionyssidae (Acari: Mesostigmata: Gamasina)

Vinarski, Maxim V., Korallo-Vinarskaya, Natalia P. (2020): An annotated catalogue of the gamasid mites associated with small mammals in Asiatic Russia. The family Hirstionyssidae (Acari: Mesostigmata: Gamasina). Zootaxa 4838 (1): 102-118, DOI: https://doi.org/10.11646/zootaxa.4838.1.

Ixodes apronophorus Schulze (Acari: Ixodida: Ixodidae): Distribution, Abundance, and Diversity of Its Mammal Hosts in West Siberia (Results of a 54-Year Long Surveillance)

Ixodes apronophorus Schulze, 1924, the marsh tick, belongs to a group of so-called “neglected” ixodid ticks, which remain underexplored compared to the most well-studied species of the genus Ixodes (I. ricinus, I. persulcatus). In this communication, we analyze and summarize the quantitative data on the abundance of this parasite, its geographical distribution, and the diversity of its small mammal hosts in the region of West Siberia (Asiatic Russia). The analyzed data represent a continuous series of observations made between 1953 and 2007, which constitutes one of the longest timeseries ever studied by acarologists. It is shown that the marsh tick in West Siberia is most common in the northern forest steppe and southern taiga landscape zones, being distributed south of 60° N. Among 24 species of small mammals registered as hosts for I. apronophorus in the studied region, three play the most important role: the European water vole (Arvicola amphibius), the tundra vole (Microtus oeconomus), and the Northern red-backed vole (Clethrionomys rutilus). The data characterizing parasitism of the marsh tick on these three hosts in various landscape zones and subzones are provided. We can report a weak albeit significant negative relationship between the abundances of I. apronophorus and its small mammal hosts. The possible explanation lies in the mismatch between the cycles of abundance characteristic of the tick and its hosts

Detection and genetic characterization of a putative novel Borrelia genospecies in Ixodes apronophorus / Ixodes persulcatus / Ixodes trianguliceps sympatric areas in Western Siberia

Four genospecies from the Borrelia burgdorferi sensu lato complex were detected in Ixodes persulcatus and Ixodes pavlovskyi ticks from Siberia and genetically characterized. The presence of Borrelia spp. in Ixodes apronophorus and Ixodes trianguliceps ticks found in Asia has never been studied. In this study, genetic diversity of B. burgdorferi s.l. was investigated in three I. persulcatus / I. trianguliceps / I. apronophorus sympatric habitats in Western Siberia. Three groups of samples were examined: (i) ticks that were taken from rodents and molted in a laboratory; (ii) non-molted ticks collected from rodents; (iii) specimens from small mammals. Expectedly, Borrelia afzelii and Borrelia bavariensis were detected in I. persulcatus and in small mammals from the studied locations. Borrelia bavariensis was first found in molted I. apronophorus and I. trianguliceps. Identical genovariants of B. bavariensis were found in I. apronophorus, I. trianguliceps, and I. persulcatus. In addition, a new Borrelia genovariant was discovered in non-molted and molted I. apronophorus and non-molted I. persulcatus and I. trianguliceps, as well as in small mammals. This new genovariant was genetically characterized using MLST and single locus sequence analysis, which indicated that the new Borrelia genovariant significantly differs from all known Borrelia species. We propose the name ''Candidatus Borrelia sibirica'' for this putative new species

Co-occurrence of ectoparasites on rodent hosts: Null model analyses of data from three continents

We studied patterns of species co-occurrence in communities of ectoparasitic arthropods (ixodid ticks, mesostigmate mites and fleas) harboured by rodent hosts from South Africa (Rhabdomys pumilio), South America (Scapteromys aquaticus and Oxymycterus rufus) and west Siberia (Apodemus agrarius, Microtus gregalis, Microtus oeconomus and Myodes rutilus) using null models. We compared frequencies of co-occurrences of parasite species or higher taxa across host individuals with those expected by chance. When non-randomness of parasite co-occurrences was detected, positive but not negative co-occurrences of parasite species or higher taxa prevailed (except for a single sample of mesostigmate mites from O. rufus). Frequency of detection of non-randomness of parasite co-occurrences differed among parasite taxa, being higher in fleas and lower in mites and ticks. This frequency differed also among host species independent of parasite taxon, being highest in Microtus species and lowest in O. rufus and S. aquaticus. We concluded that the pattern of species co-occurrence in ectoparasite communities on rodent hosts is predominantly positive, depends on life history of parasites and may be affected to a great extent by life history of a host.Fil: Krasnov, Boris R.. Ben Gurion University of the Negev; IsraelFil: Matthee, Sonja. Stellenbosch University; SudáfricaFil: Lareschi, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Korallo Vinarskaya, Natalia P.. Omsk Research Institute of Natural Foci Infections; RusiaFil: Vinarski, Maxim V.. Omsk State Pedagogical University; Rusi

Data from: Temporal dynamics of direct reciprocal and indirect effects in a host-parasite network

1. Temporal variation in the direct and indirect influence that hosts and parasites exert on each other is still poorly understood. However, variation in species’ influence due to species and interactions turnover can have important consequences for host community dynamics and/or for parasite transmission dynamics, and eventually for the risk of zoonotic diseases. 2. We used data on a network of small mammals and their ectoparasites surveyed over six years to test hypotheses exploring (1) the temporal variability in direct and indirect influences species exert on each other in a community, and (2) the differences in temporal variability of direct/indirect influences between temporally persistent and temporally intermittent species. 3. We modelled the temporal variation in: (1) direct reciprocal influence between hosts and parasites (hosts providing resources to parasites and parasites exploiting the resources of hosts), using an asymmetry index; and (2) indirect influence among species within a community (e.g. facilitation of parasite infestation by other parasites), using betweenness centrality. We also correlated asymmetry and centrality to examine the relationship between them. 4. Network dynamics was determined by temporally persistent species but even those species had strong among-species heterogeneity in the temporal variation of the direct/indirect effects they exerted. In addition, there was a significant positive linear correlation between asymmetry and centrality. 5. We conclude that the temporal dynamics of host-parasite interactions is driven by temporally persistent hosts. However, even within this group of persistent species, some exhibit large temporal variation, such that the functional roles they play (e.g. in promoting parasite transmission) change over time. In addition, parasites having a large negative impact on hosts are also those facilitating the spread of other parasites through the entire host community. Our results provide new insights into community dynamics and can be applied in the management of antagonistic networks aimed at preventing disease outbreaks

Data from: Temporal dynamics of direct reciprocal and indirect effects in a host-parasite network

1. Temporal variation in the direct and indirect influence that hosts and parasites exert on each other is still poorly understood. However, variation in species’ influence due to species and interactions turnover can have important consequences for host community dynamics and/or for parasite transmission dynamics, and eventually for the risk of zoonotic diseases. 2. We used data on a network of small mammals and their ectoparasites surveyed over six years to test hypotheses exploring (1) the temporal variability in direct and indirect influences species exert on each other in a community, and (2) the differences in temporal variability of direct/indirect influences between temporally persistent and temporally intermittent species. 3. We modelled the temporal variation in: (1) direct reciprocal influence between hosts and parasites (hosts providing resources to parasites and parasites exploiting the resources of hosts), using an asymmetry index; and (2) indirect influence among species within a community (e.g. facilitation of parasite infestation by other parasites), using betweenness centrality. We also correlated asymmetry and centrality to examine the relationship between them. 4. Network dynamics was determined by temporally persistent species but even those species had strong among-species heterogeneity in the temporal variation of the direct/indirect effects they exerted. In addition, there was a significant positive linear correlation between asymmetry and centrality. 5. We conclude that the temporal dynamics of host-parasite interactions is driven by temporally persistent hosts. However, even within this group of persistent species, some exhibit large temporal variation, such that the functional roles they play (e.g. in promoting parasite transmission) change over time. In addition, parasites having a large negative impact on hosts are also those facilitating the spread of other parasites through the entire host community. Our results provide new insights into community dynamics and can be applied in the management of antagonistic networks aimed at preventing disease outbreaks

Co-occurrence and phylogenetic distance in communities of mammalian ectoparasites: limiting similarity versus environmental filtering

International audienceSimilarity between species plays a key role in the processes governing community assembly. The co‐occurrence of highly similar species may be unlikely if their similar needs lead to intense competition (limiting similarity). On the other hand, persistence in a particular habitat may require certain traits, such that communities end up consisting of species sharing the same traits (environmental filtering). Relatively little information exists on the relative importance of these processes in structuring parasite communities. Assuming that phylogenetic relatedness reflects ecological similarity, we tested whether the co‐occurrence of pairs of flea species (Siphonaptera) on the same host individuals was explained by the phylogenetic distance between them, among 40 different samples of mammalian hosts (rodents and shrews) from different species, areas or seasons. Our results indicate that frequency of co‐occurrence between flea species increased with decreasing phylogenetic distance between them in 37 out of 40 community samples, with 14 of these correlations being statistically significant. A meta‐analysis across all samples confirmed the overall trend for closely related species to co‐occur more frequently on the same individual hosts than expected by chance, independently of the identity of the host species or of environmental conditions. These findings suggest that competition between closely related, and therefore presumably ecologically similar, species is not important in shaping flea communities. Instead, if only fleas with certain behavioural, ecological and physiological properties can encounter and exploit a given host, and if phylogenetic relationships determine trait similarity among flea species, then a process akin to environmental filtering, or host filtering, could favour the co‐occurrence of related species on the same host

Male hosts drive infracommunity structure of ectoparasites

We studied the co-occurrence of flea species in infracommunities of 16 rodents from four regions (South Africa, Tanzania, central Europe and western Siberia) using null models, and predicted that flea co-occurrences will be expressed more strongly in male than in female hosts. We examined patterns of co-occurrence (measured as the C score) in infracommunities of fleas that are parasitic on male and female hosts by comparing co-occurrence frequencies with those expected by chance. When a significant degree of nonrandomness in flea co-occurrences was detected, it indicated aggregative infracommunity structure. In Tanzanian rodents, no significant flea co-occurrences were detected in either male or female hosts. In a South African rodent, significant flea co-occurrences were not detected in males, but were found in females in some localities. In Palaearctic rodents, significant nonrandomness was detected either equally for males and females or more frequently in males than in females. Meta-analyses demonstrated that the frequency of the detection of nonrandomness in flea co-occurrences was significantly higher in male than in female hosts. The values of the standardized effect size (SES) for the C score differed significantly among host species, but not between host genders. When the Palaearctic hosts were analyzed separately, the effects of both host gender and species appeared to be significant, with the SES values for the C score in males being smaller than those in females. The strength of the gender difference in the manifestation of flea community structure increased with increasing gender difference in flea species richness, and with decreasing gender difference in flea prevalence for the Palaearctic hosts. We conclude that male hosts are the main drivers of flea infracommunity structure. However, the manifestation of gender bias in flea community structure varies among host species, and is likely determined by the pattern of species-specific spatial behavior. © 2011 Springer-Verlag.Articl