Sample records for non-natal host species

  1. Host species exploitation and discrimination by animal parasites (United States)

    Forbes, Mark R.; Morrill, André; Schellinck, Jennifer


    Parasite species often show differential fitness on different host species. We developed an equation-based model to explore conditions favouring host species exploitation and discrimination. In our model, diploid infective stages randomly encountered hosts of two species; the parasite's relative fitness in exploiting each host species, and its ability to discriminate between them, was determined by the parasite's genotype at two independent diallelic loci. Relative host species frequency determined allele frequencies at the exploitation locus, whereas differential fitness and combined host density determined frequency of discrimination alleles. The model predicts instances where populations contain mixes of discriminatory and non-discriminatory infective stages. Also, non-discriminatory parasites should evolve when differential fitness is low to moderate and when combined host densities are low, but not so low as to cause parasite extinction. A corollary is that parasite discrimination (and host-specificity) increases with higher combined host densities. Instances in nature where parasites fail to discriminate when differential fitness is extreme could be explained by one host species evolving resistance, following from earlier selection for parasite non-discrimination. Similar results overall were obtained for haploid extensions of the model. Our model emulates multi-host associations and has implications for understanding broadening of host species ranges by parasites. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289258

  2. Species formation by host shifting in avian malaria parasites. (United States)

    Ricklefs, Robert E; Outlaw, Diana C; Svensson-Coelho, Maria; Medeiros, Matthew C I; Ellis, Vincenzo A; Latta, Steven


    The malaria parasites (Apicomplexa: Haemosporida) of birds are believed to have diversified across the avian host phylogeny well after the origin of most major host lineages. Although many symbionts with direct transmission codiversify with their hosts, mechanisms of species formation in vector-borne parasites, including the role of host shifting, are poorly understood. Here, we examine the hosts of sister lineages in a phylogeny of 181 putative species of malaria parasites of New World terrestrial birds to determine the role of shifts between host taxa in the formation of new parasite species. We find that host shifting, often across host genera and families, is the rule. Sympatric speciation by host shifting would require local reproductive isolation as a prerequisite to divergent selection, but this mechanism is not supported by the generalized host-biting behavior of most vectors of avian malaria parasites. Instead, the geographic distribution of individual parasite lineages in diverse hosts suggests that species formation is predominantly allopatric and involves host expansion followed by local host-pathogen coevolution and secondary sympatry, resulting in local shifting of parasite lineages across hosts.

  3. Mating and host density affect host feeding and parasitism in two species of whitefly parasitoids

    Institute of Scientific and Technical Information of China (English)

    Lian-Sheng Zang; Tong-Xian Liu; Fan Zhang; Shu-Sen Shi; Fang-Hao Wan


    The parasitoids in the genera of Encarsia and Eretmocerus(Hymenoptera:Aphelinidae)are important biological control agents of whiteflies,and some of them not only parasitize hosts but also kill them with strong host-feeding capacity.Two whitefly parasitoid species,Encarsia sophia and Eretmocerus melanoscutus were examined to determine if mating and host density affected their host feeding and parasitism.The whitefly host,Bemisia tabaci,was presented to these two wasp species in densities of 10,20,30,40,50 and 60 third-instar nymphs per clip cage.Mated whitefly parasitoid females fed on more hosts than unmated females under a range of host densities(under all six host densities for En.sophia; under the densities of 40 nymphs or more for Er.melanoscutus).Meanwhile,mated females parasitized more whitefly nymphs than unmated females under all host densities for both species.With increase of host density,mated or unmated Er.melanoscutus females killed more hosts by host feeding and parasitism.Mated En.sophia females killed more hosts by host feeding with increase of host density,whereas unmated females did not parasitze whitefly nymphs at all.Our results suggest that only mated female parasitoids with host-feeding behavior should be released in crop systems to increase their bio-control efficiency.

  4. Patterns of host adaptation in fly infecting Entomophthora species

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Jensen, Annette Bruun; Eilenberg, Jørgen

    .g. Entomophthora, Strongwellsea and Entomophaga). Species diversification of the obligate IPF within Entomophthoromycota thus seems to be primarily driven by co-evolutionary host adaptation to specific insect families, genera or species-complexes, but the underlying genetic factors of host adaptation......Insect pathogenic fungi (IPF) differ widely in their capability to infect different hosts. Some are generalists and will, given a sufficient number of infectious spores are present, infect almost any species of insect (e.g. Hypocrealean Metarhizium and Beauveria). Members of a different main IPF...... phylum Entomophthoromycota generally have more narrow host-ranges where some species for example only infect aphids or only locusts. Certain species (or strains) are even more host specific and are only known to infect a single or very few taxonomically related insect species under natural conditions (e...

  5. Fish, fans and hydroids: host species of pygmy seahorses (United States)

    Reijnen, Bastian T.; van der Meij, Sancia E.T.; van Ofwegen, Leen P.


    Abstract An overview of the octocoral and hydrozoan host species of pygmy seahorses is provided based on literature records and recently collected field data for Hippocampus bargibanti, Hippocampus denise and Hippocampus pontohi. Seven new associations are recognized and an overview of the so far documented host species is given. A detailed re-examination of octocoral type material and a review of the taxonomic history of the alcyonacean genera Annella (Subergorgiidae) and Muricella (Acanthogorgiidae) are included as baseline for future revisions. The host specificity and colour morphs of pygmy seahorses are discussed, as well as the reliability of (previous) identifications and conservation issues. PMID:21747677

  6. Does multiple hosts mean multiple parasites? Population genetic structure of Schistosoma japonicum between definitive host species. (United States)

    Wang, T P; Shrivastava, J; Johansen, M V; Zhang, S Q; Wang, F F; Webster, J P


    Multi-host parasites, those capable of infecting more than one species of host, are responsible for the majority of all zoonotic, emerging or persistent human and animal diseases and are considered one of the major challenges for the biomedical sciences in the 21st century. We characterized the population structure of the multi-host parasite Schistosoma japonicum in relation to its definitive host species by genotyping miracidia collected from humans and domestic animals across five villages around the Yangtze River in Anhui Province, mainland China, using microsatellite markers. High levels of polymorphisms were observed and two main genetic clusters were identified which separated water buffalo, cattle and humans from goats, pigs, dogs and cats. We thereby believe that we present the first evidence of definitive host-based genetic variation in Schistosoma japonicum which has important epidemiological, evolutionary, medical and veterinary implications.

  7. Host insect species of Ophiocordyceps sinensis: a review

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    Xiao-Liang Wang


    Full Text Available Ophiocordyceps sinensis (≡ Cordyceps sinensis is one of the most valued medicinal fungi in China, used for its invigorating effects in strengthening the body and restoring energy. The fungus parasitizes larvae of moths and converts them into sclerotia from which the fungus fruiting body grows. Since the late 1950s, considerable effort has been devoted to the study of host insects related to the fungus. In the present paper, the research history of insect species associated with O. sinensis is briefly reviewed and an extensive literature survey is presented. Ninety-one insect names, spanning 13 genera, related to host insects of O. sinensis are investigated. The relationships between the reported insect species and O. sinensis are analyzed. Fifty-seven of these are considered as recognizable potential host species of the fungus distributed throughout the Tibetan Plateau, whilst eight are considered as indeterminate hosts and 26 as non-hosts. Among the names of recognizable potential host insects, three are invalid (nomen nudum and require further study. This work provides basic information for management of the insect resources and for the conservation and sustainable use of O. sinensis.

  8. Biodiversity of Asterina species on Neotropical host plants: new species and records from Panama. (United States)

    Hofmann, T A; Piepenbring, M


    Two new species of the genus Asterina are described from living leaves collected in provinces Chiriquí and Bocas del Toro in western Panama. Asterina alloplecti on Alloplectus ichtyoderma (Gesneriaceae) differs from other Asterina on Gesneriaceae by its stalked appressoria and host relationship. Asterina compsoneurae on Compsoneura sprucei (Myristicaceae) can be distinguished from other members of Asterina on Myristicaceae by its larger ascomata, larger, prominently spinose ascospores and host relationship. New records for Panama are Asterina corallopoda from a new host plant species (Solanum trizygum, Solanaceae), A. diplopoda, A. ekmanii from a new host plant species (Gonzalagunia rudis, Rubiaceae), A. siphocampyli from a new host plant genus and species (Burmeistera vulgaris, Campanulaceae) and A. styracina from a new host-plant species (Styrax argenteus, Styracaceae). This study increases the number of species of Asterina known for Panama from 12 to 19 and the number of Asterinaceae from 14 to 21. Asterina corallopoda, A. diplopoda, A. ekmanii, A. siphocampyli and A. styracina are illustrated for the first time. A phylogeny inferred from the analysis of LSU rDNA sequences of species of Asterina is presented. The diversity and host-plant patterns of known Neotropical species of Asterina are discussed.

  9. Bartonella species and their ectoparasites: selective host adaptation or strain selection between the vector and the mammalian host? (United States)

    Tsai, Yi-Lun; Chang, Chao-Chin; Chuang, Shih-Te; Chomel, Bruno B


    A wide range of blood-sucking arthropods have either been confirmed or are suspected as important vectors in Bartonella transmission to mammals, including humans. Overall, it appears that the diversity of Bartonella species DNA identified in ectoparasites is much broader than the species detected in their mammalian hosts, suggesting a mechanism of adaptation of Bartonella species to their host-vector ecosystem. However, these mechanisms leading to the fitness between the vectors and their hosts still need to be investigated.

  10. Host range, host ecology, and distribution of more than 11800 fish parasite species (United States)

    Strona, Giovanni; Palomares, Maria Lourdes D.; Bailly, Nicholas; Galli, Paolo; Lafferty, Kevin D.


    Our data set includes 38 008 fish parasite records (for Acanthocephala, Cestoda, Monogenea, Nematoda, Trematoda) compiled from the scientific literature, Internet databases, and museum collections paired to the corresponding host ecological, biogeographical, and phylogenetic traits (maximum length, growth rate, life span, age at maturity, trophic level, habitat preference, geographical range size, taxonomy). The data focus on host features, because specific parasite traits are not consistently available across records. For this reason, the data set is intended as a flexible resource able to extend the principles of ecological niche modeling to the host–parasite system, providing researchers with the data to model parasite niches based on their distribution in host species and the associated host features. In this sense, the database offers a framework for testing general ecological, biogeographical, and phylogenetic hypotheses based on the identification of hosts as parasite habitat. Potential applications of the data set are, for example, the investigation of species–area relationships or the taxonomic distribution of host-specificity. The provided host–parasite list is that currently used by Fish Parasite Ecology Software Tool (FishPEST,, which is a website that allows researchers to model several aspects of the relationships between fish parasites and their hosts. The database is intended for researchers who wish to have more freedom to analyze the database than currently possible with FishPEST. However, for readers who have not seen FishPEST, we recommend using this as a starting point for interacting with the database.

  11. Panamanian frog species host unique skin bacterial communities

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    Lisa K. Belden


    Full Text Available Vertebrates, including amphibians, host diverse symbiotic microbes that contribute to host disease resistance. Globally, and especially in montane tropical systems, many amphibian species are threatened by a chytrid fungus, Batrachochytrium dendrobatidis (Bd, that causes a lethal skin disease. Bd therefore may be a strong selective agent on the diversity and function of the microbial communities inhabiting amphibian skin. In Panamá, amphibian population declines and the spread of Bd have been tracked. In 2012, we completed a field survey in Panamá to examine frog skin microbiota in the context of Bd infection. We focused on three frog species and collected two skin swabs per frog from a total of 136 frogs across four sites that varied from west to east in the time since Bd arrival. One swab was used to assess bacterial community structure using 16S rRNA amplicon sequencing and to determine Bd infection status, and one was used to assess metabolite diversity, as the bacterial production of anti-fungal metabolites is an important disease resistance function. The skin microbiota of the three Panamanian frog species differed in OTU (operational taxonomic unit, ~bacterial species community composition and metabolite profiles, although the pattern was less strong for the metabolites. Comparisons between frog skin bacterial communities from Panamá and the US suggest broad similarities at the phylum level, but key differences at lower taxonomic levels. In our field survey in Panamá, across all four sites, only 35 individuals (~26% were Bd infected. There was no clustering of OTUs or metabolite profiles based on Bd infection status and no clear pattern of west-east changes in OTUs or metabolite profiles across the four sites. Overall, our field survey data suggest that different bacterial communities might be producing broadly similar sets of metabolites across frog hosts and sites. Community structure and function may not be as tightly coupled in

  12. Trophic relationships between the parasitic plant species Phelipanche ramosa (L. and different hosts depending on host phenological stage and host growth rate

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    Delphine Moreau


    Full Text Available Phelipanche ramosa (L. Pomel (branched broomrape is a holoparasitic plant that reproduces on crops and also on weeds, which contributes to increase the parasite seed bank in fields. This parasite extracts all its nutrients at the host's expense so that host-parasite trophic relationships are crucial to determine host and parasite growth. This study quantified the intensity with which P. ramosa draws assimilates from its host and analyzed whether it varied with host species, host phenological stage and host growth rate. A greenhouse experiment was conducted on three host species: the crop species Brassica napus (L. (oilseed rape and two weed species, Capsella bursa-pastoris (L. Medik. and Geranium dissectum (L.. Plants were grown with or without P. ramosa and under three light levels to modulate host growth rate. The proportion of host biomass loss due to parasitism by P. ramosa differed between host species (at host fructification, biomass loss ranged from 34% to 84%. Brassica napus and C. bursa-pastoris displayed a similar response to P. ramosa, probably because they belong to the same botanical family. The sensitivity to P. ramosa in each host species could be related to the precocity of P. ramosa development on them. Host compartments could be ranked as a function of their sensitivity to parasitism, with the reproductive compartment being the most severely affected, followed by stems and roots. The proportion of biomass allocated to leaves was not reduced by parasitism. The proportion of pathosystem biomass allocated to the parasite depended on host species. It generally increased with host stage progression but was constant across light induced-host growth rate, showing that P. ramosa adapts its growth to host biomass production. The rank order of host species in terms of sink strength differed from that in terms of host sensitivity. Finally, for B. napus, the biomass of individual parasite shoots decreased with increasing their number per

  13. Effects of rearing host species on the host-feeding capacity and parasitism of the whitefly parasitoid Encarsia formosa. (United States)

    Dai, Peng; Ruan, Changchun; Zang, Liansheng; Wan, Fanghao; Liu, Linzhou


    Parasitoids of the Encarsia genus (Hymenoptera: Aphelinidae) are important biological control agents against whiteflies. Some of the species in this genus not only parasitize their hosts, but also kill them through host feeding. The whitefly parasitoid, Encarsia formosa Gahan, was examined to determine whether the rearing host species affects its subsequent host-feeding capacity and parasitism. E. formosa wasps were reared on Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) and Bemisia tabaci (Gennadius) 'Q', and their subsequent host-feeding capacity and parasitism of T. vaporariorum and B. tabaci were examined. E. formosa reared on T. vaporariorum were significantly larger in body size than those reared on B. tabaci, but these wasps killed a similar number of whitefly nymphs by host feeding when they attacked the same host species on which they were reared. Regardless of the species on which it was reared, E. formosa fed significantly more on the B. tabaci nymphs than on the T. vaporariorum nymphs. The number of whitefly nymphs parasitized by E. formosa differed between the wasps reared on T. vaporariorum and those reared on B. tabaci depending on which whitefly species was offered as a host. In addition, the wasps reared on T. vaporariorum parasitized significantly more on T. vaporariorum than those reared on B. tabaci. The wasps reared on B. tabaci, however, parasitized similar numbers of whiteflies of both host species. The results indicated that the host-feeding capacity of E. formosa was affected more by the host species attacked than by the rearing host species, but the parasitism was affected by the host species attacked and the rearing host species. Generally, E. formosa reared on T. vaporariorum killed more T. vaporariorum nymphs by parasitism and host feeding than those reared on B. tabaci. Additionally, a similar number of B. tabaci nymphs were killed by parasitism and host feeding regardless of the rearing host species. Currently

  14. Molecular systematics of pinniped hookworms (Nematoda: Uncinaria): species delimitation, host associations and host-induced morphometric variation. (United States)

    Nadler, Steven A; Lyons, Eugene T; Pagan, Christopher; Hyman, Derek; Lewis, Edwin E; Beckmen, Kimberlee; Bell, Cameron M; Castinel, Aurelie; Delong, Robert L; Duignan, Padraig J; Farinpour, Cher; Huntington, Kathy Burek; Kuiken, Thijs; Morgades, Diana; Naem, Soraya; Norman, Richard; Parker, Corwin; Ramos, Paul; Spraker, Terry R; Berón-Vera, Bárbara


    Hookworms of the genus Uncinaria have been widely reported from juvenile pinnipeds, however investigations of their systematics has been limited, with only two species described, Uncinaria lucasi from northern fur seals (Callorhinus ursinus) and Uncinaria hamiltoni from South American sea lions (Otaria flavescens). Hookworms were sampled from these hosts and seven additional species including Steller sea lions (Eumetopias jubatus), California sea lions (Zalophus californianus), South American fur seals (Arctocephalus australis), Australian fur seals (Arctocephalus pusillus), New Zealand sea lions (Phocarctos hookeri), southern elephant seals (Mirounga leonina), and the Mediterranean monk seal (Monachus monachus). One hundred and thirteen individual hookworms, including an outgroup species, were sequenced for four genes representing two loci (nuclear ribosomal DNA and mitochondrial DNA). Phylogenetic analyses of these sequences recovered seven independent evolutionary lineages or species, including the described species and five undescribed species. The molecular evidence shows that U. lucasi parasitises both C. ursinus and E. jubatus, whereas U. hamiltoni parasitises O. flavescens and A. australis. The five undescribed hookworm species were each associated with single host species (Z. californianus, A. pusillus, P. hookeri, M. leonina and M. monachus). For parasites of otarids, patterns of Uncinaria host-sharing and phylogenetic relationships had a strong biogeographic component with separate clades of parasites from northern versus southern hemisphere hosts. Comparison of phylogenies for these hookworms and their hosts suggests that the association of U. lucasi with northern fur seals results from a host-switch from Steller sea lions. Morphometric data for U. lucasi shows marked host-associated size differences for both sexes, with U. lucasi individuals from E. jubatus significantly larger. This result suggests that adult growth of U. lucasi is reduced within the

  15. Ectomycorrhizal fungal richness declines towards the host species' range edge. (United States)

    Lankau, Richard A; Keymer, Daniel P


    Plant range boundaries are generally considered to reflect abiotic conditions; however, a rise in negative or decline in positive species interactions at range margins may contribute to these stable boundaries. While evidence suggests that pollinator mutualisms may decline near range boundaries, little is known about other important plant mutualisms, including microbial root symbionts. Here, we used molecular methods to characterize root-associated fungal communities in populations of two related temperate tree species from across the species' range in the eastern United States. We found that ectomycorrhizal fungal richness on plant roots declined with distance from the centre of the host species range. These patterns were not evident in nonmycorrhizal fungal communities on roots nor in fungal communities in bulk soil. Climatic and soil chemical variables could not explain these biogeographic patterns, although these abiotic gradients affected other components of the bulk soil and rhizosphere fungal community. Depauperate ectomycorrhizal fungal communities may represent an underappreciated challenge to marginal tree populations, especially as rapid climate change pushes these populations outside their current climate niche.

  16. Do parasitic trematode cercariae demonstrate a preference for susceptible host species?

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    Brittany F Sears

    Full Text Available Many parasites are motile and exhibit behavioural preferences for certain host species. Because hosts can vary in their susceptibility to infections, parasites might benefit from preferentially detecting and infecting the most susceptible host, but this mechanistic hypothesis for host-choice has rarely been tested. We evaluated whether cercariae (larval trematode parasites prefer the most susceptible host species by simultaneously presenting cercariae with four species of tadpole hosts. Cercariae consistently preferred hosts in the following order: Anaxyrus ( = Bufo terrestris (southern toad, Hyla squirella (squirrel tree frog, Lithobates ( = Rana sphenocephala (southern leopard frog, and Osteopilus septentrionalis (Cuban tree frog. These host species varied in susceptibility to cercariae in an order similar to their attractiveness with a correlation that approached significance. Host attractiveness to parasites also varied consistently and significantly among individuals within a host species. If heritable, this individual-level host variation would represent the raw material upon which selection could act, which could promote a Red Queen "arms race" between host cues and parasite detection of those cues. If, in general, motile parasites prefer to infect the most susceptible host species, this phenomenon could explain aggregated distributions of parasites among hosts and contribute to parasite transmission rates and the evolution of virulence. Parasite preferences for hosts belie the common assumption of disease models that parasites seek and infect hosts at random.

  17. The integrative taxonomic approach reveals host specific species in an encyrtid parasitoid species complex.

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    Douglas Chesters

    Full Text Available Integrated taxonomy uses evidence from a number of different character types to delimit species and other natural groupings. While this approach has been advocated recently, and should be of particular utility in the case of diminutive insect parasitoids, there are relatively few examples of its application in these taxa. Here, we use an integrated framework to delimit independent lineages in Encyrtus sasakii (Hymenoptera: Chalcidoidea: Encyrtidae, a parasitoid morphospecies previously considered a host generalist. Sequence variation at the DNA barcode (cytochrome c oxidase I, COI and nuclear 28S rDNA loci were compared to morphometric recordings and mating compatibility tests, among samples of this species complex collected from its four scale insect hosts, covering a broad geographic range of northern and central China. Our results reveal that Encyrtus sasakii comprises three lineages that, while sharing a similar morphology, are highly divergent at the molecular level. At the barcode locus, the median K2P molecular distance between individuals from three primary populations was found to be 11.3%, well outside the divergence usually observed between Chalcidoidea conspecifics (0.5%. Corroborative evidence that the genetic lineages represent independent species was found from mating tests, where compatibility was observed only within populations, and morphometric analysis, which found that despite apparent morphological homogeneity, populations clustered according to forewing shape. The independent lineages defined by the integrated analysis correspond to the three scale insect hosts, suggesting the presence of host specific cryptic species. The finding of hidden host specificity in this species complex demonstrates the critical role that DNA barcoding will increasingly play in revealing hidden biodiversity in taxa that present difficulties for traditional taxonomic approaches.

  18. Spodoptera frugiperda (Lepidoptera: Noctuidae) host-plant variants: two host strains or two distinct species? (United States)

    Dumas, Pascaline; Legeai, Fabrice; Lemaitre, Claire; Scaon, Erwan; Orsucci, Marion; Labadie, Karine; Gimenez, Sylvie; Clamens, Anne-Laure; Henri, Hélène; Vavre, Fabrice; Aury, Jean-Marc; Fournier, Philippe; Kergoat, Gael J; d'Alençon, Emmanuelle


    The moth Spodoptera frugiperda is a well-known pest of crops throughout the Americas, which consists of two strains adapted to different host-plants: the first feeds preferentially on corn, cotton and sorghum whereas the second is more associated with rice and several pasture grasses. Though morphologically indistinguishable, they exhibit differences in their mating behavior, pheromone compositions, and show development variability according to the host-plant. Though the latter suggest that both strains are different species, this issue is still highly controversial because hybrids naturally occur in the wild, not to mention the discrepancies among published results concerning mating success between the two strains. In order to clarify the status of the two host-plant strains of S. frugiperda, we analyze features that possibly reflect the level of post-zygotic isolation: (1) first generation (F1) hybrid lethality and sterility; (2) patterns of meiotic segregation of hybrids in reciprocal second generation (F2), as compared to the meiosis of the two parental strains. We found a significant reduction of mating success in F1 in one direction of the cross and a high level of microsatellite markers showing transmission ratio distortion in the F2 progeny. Our results support the existence of post-zygotic reproductive isolation between the two laboratory strains and are in accordance with the marked level of genetic differentiation that was recovered between individuals of the two strains collected from the field. Altogether these results provide additional evidence in favor of a sibling species status for the two strains.

  19. Lichenicolous fungi show population subdivision by host species but do not share population history with their hosts. (United States)

    Werth, Silke; Millanes, Ana María; Wedin, Mats; Scheidegger, Christoph


    Lichenicolous fungi are a species-rich biological group growing on lichen thalli. Here, we analyze the genetic structure of the lichenicolous basidiomycete Tremella lobariacearum and three host species (Lobaria pulmonaria, Lobaria macaronesica, and Lobaria immixta) in Macaronesia. We used ordination and analysis of molecular variance to investigate the structuring of genetic variation, and a simulation test to investigate whether rDNA haplotypes of T. lobariacearum were significantly associated with host species. To investigate the evolutionary and demographic history of the lichenicolous fungus and its hosts, we used coalescent samplers to generate trees, and Bayesian skyline plots. We found that the hosts were most important in structuring populations of the lichenicolous species. Despite their wide geographic distribution, the same haplotypes of T. lobariacearum consistently associated with a given host species. Our results suggest that the Lobaria hosts create a selective environment for the lichenicolous fungus. Both the pathogen and the host populations exhibited substantial genetic structure. However, evolutionary and demographic histories differed between the parasite and its hosts, as evidenced by different divergence times and tree topologies.

  20. Are all species of Pseudorhabdosynochus strictly host specific? - a molecular study


    Schoelinck, Charlotte; Cruaud, Corinne; Justine, Jean-Lou


    International audience; Species of the diplectanid monogenean genus Pseudorhabdosynochus are strictly host-specific (specialist), with the exception of P. cyanopodus, which was reported in New Caledonia, South Pacific, from two host species, Epinephelus cyanopodus and E. chlorostigma. We sequenced the COI gene of both host fish species and of their monogeneans. Morphological identification and pairwise distances showed that the two fish species were distinct (difference 6.1-6.6%), but that th...

  1. Novel application of species richness estimators to predict the host range of parasites. (United States)

    Watson, David M; Milner, Kirsty V; Leigh, Andrea


    Host range is a critical life history trait of parasites, influencing prevalence, virulence and ultimately determining their distributional extent. Current approaches to measure host range are sensitive to sampling effort, the number of known hosts increasing with more records. Here, we develop a novel application of results-based stopping rules to determine how many hosts should be sampled to yield stable estimates of the number of primary hosts within regions, then use species richness estimation to predict host ranges of parasites across their distributional ranges. We selected three mistletoe species (hemiparasitic plants in the Loranthaceae) to evaluate our approach: a strict host specialist (Amyema lucasii, dependent on a single host species), an intermediate species (Amyema quandang, dependent on hosts in one genus) and a generalist (Lysiana exocarpi, dependent on many genera across multiple families), comparing results from geographically-stratified surveys against known host lists derived from herbarium specimens. The results-based stopping rule (stop sampling bioregion once observed host richness exceeds 80% of the host richness predicted using the Abundance-based Coverage Estimator) worked well for most bioregions studied, being satisfied after three to six sampling plots (each representing 25 host trees) but was unreliable in those bioregions with high host richness or high proportions of rare hosts. Although generating stable predictions of host range with minimal variation among six estimators trialled, distribution-wide estimates fell well short of the number of hosts known from herbarium records. This mismatch, coupled with the discovery of nine previously unrecorded mistletoe-host combinations, further demonstrates the limited ecological relevance of simple host-parasite lists. By collecting estimates of host range of constrained completeness, our approach maximises sampling efficiency while generating comparable estimates of the number of primary

  2. Microsatellite analysis reveals strong but differential impact of a social parasite on its two host species. (United States)

    Fischer-Blass, Birgit; Heinze, Jürgen; Foitzik, Susanne


    The speed and the dynamics of the co-evolutionary process strongly depend on the relative strengths of reciprocal selection pressures exerted by the interacting species. Here, we investigate the influence of an obligate social parasite, the slave-making ant Harpagoxenus sublaevis, on populations of the two main host species Leptothorax acervorum and Leptothorax muscorum from a German ant community. A combination of genetic and demographic data allowed us to analyse the consequences of raiding pressure on the hosts' life history and possible host preferences of the parasite. We can demonstrate that slave raids during which the social parasite pillages brood from neighbouring host colonies are both frequent and extremely destructive for both host species. Microsatellite analysis showed that, on average, a single slave-maker colony conducts more than three raids per year and that host colonies mostly perish in the aftermath of these parasite attacks. Only in few cases, surviving nests of previously raided host colonies were found in the surroundings of slave-maker colonies. As a consequence of the high prevalence of parasites and their recurrent and devastating slave raids on host colonies, the life expectancy of host colonies was severely reduced. Combining our results on host-specific parasitic colony founding and raiding frequencies with the post-raid survival rate, we can demonstrate an overall higher mortality rate for the smaller host species L. muscorum. This might be caused by a preference of H. sublaevis for this secondary host species as demographic data on host species usage indicate.

  3. Plasmodium prevalence across avian host species is positively associated with exposure to mosquito vectors. (United States)

    Medeiros, Matthew C I; Ricklefs, Robert E; Brawn, Jeffrey D; Hamer, Gabriel L


    The prevalence of vector-borne parasites varies greatly across host species, and this heterogeneity has been used to relate infectious disease susceptibility to host species traits. However, a few empirical studies have directly associated vector-borne parasite prevalence with exposure to vectors across hosts. Here, we use DNA sequencing of blood meals to estimate utilization of different avian host species by Culex mosquitoes, and relate utilization by these malaria vectors to avian Plasmodium prevalence. We found that avian host species that are highly utilized as hosts by avian malaria vectors are significantly more likely to have Plasmodium infections. However, the effect was not consistent among individual Plasmodium taxa. Exposure to vector bites may therefore influence the relative number of all avian Plasmodium infections among host species, while other processes, such as parasite competition and host-parasite coevolution, delimit the host distributions of individual Plasmodium species. We demonstrate that links between avian malaria susceptibility and host traits can be conditioned by patterns of exposure to vectors. Linking vector utilization rates to host traits may be a key area of future research to understand mechanisms that produce variation in the prevalence of vector-borne pathogens among host species.

  4. Inferring phylogeny and speciation of Gymnosporangium species, and their coevolution with host plants (United States)

    Zhao, Peng; Liu, Fang; Li, Ying-Ming; Cai, Lei


    Gymnosporangium species (Pucciniaceae, Pucciniales) cause serious diseases and significant economic losses to apple cultivars. Most of the reported species are heteroecious and complete their life cycles on two different plant hosts belonging to two unrelated genera, i.e. Juniperus and Malus. However, the phylogenetic relationships among Gymnosporangium species and the evolutionary history of Gymnosporangium on its aecial and telial hosts were still undetermined. In this study, we recognized species based on rDNA sequence data by using coalescent method of generalized mixed Yule-coalescent (GMYC) and Poisson Tree Processes (PTP) models. The evolutionary relationships of Gymnosporangium species and their hosts were investigated by comparing the cophylogenetic analyses of Gymnosporangium species with Malus species and Juniperus species, respectively. The concordant results of GMYC and PTP analyses recognized 14 species including 12 known species and two undescribed species. In addition, host alternations of 10 Gymnosporangium species were uncovered by linking the derived sequences between their aecial and telial stages. This study revealed the evolutionary process of Gymnosporangium species, and clarified that the aecial hosts played more important roles than telial hosts in the speciation of Gymnosporangium species. Host switch, losses, duplication and failure to divergence all contributed to the speciation of Gymnosporangium species. PMID:27385413

  5. Olfactory cues from different plant species in host selection by female pea moths. (United States)

    Thöming, Gunda; Norli, Hans Ragnar


    In herbivorous insects specialized on few plant species, attraction to host odor may be mediated by volatiles common to all host species, by specific compounds, or combinations of both. The pea moth Cydia nigricana is an important pest of the pea. Volatile signatures of four host plant species were studied to identify compounds involved in pea moth host selection and to improve previously reported attractive volatile blends. P. sativum and alternative Fabaceae host species were compared regarding female attraction, oviposition, and larval performance. Pea moth females were strongly attracted to the sweet pea Lathyrus odoratus, but larval performance on that species was moderate. Chemical analyses of sweet pea odor and electrophysiological responses of moth antennae led to identification of seven sweet-pea-specific compounds and ten compounds common to all tested host species. Blends of these specific and common cues were highly attractive to mated pea moth females in wind tunnel and field experiments.

  6. Cross-species infection trials reveal cryptic parasite varieties and a putative polymorphism shared among host species. (United States)

    Luijckx, Pepijn; Duneau, David; Andras, Jason P; Ebert, Dieter


    A parasite's host range can have important consequences for ecological and evolutionary processes but can be difficult to infer. Successful infection depends on the outcome of multiple steps and only some steps of the infection process may be critical in determining a parasites host range. To test this hypothesis, we investigated the host range of the bacterium Pasteuria ramosa, a Daphnia parasite, and determined the parasites success in different stages of the infection process. Multiple genotypes of Daphnia pulex, Daphnia longispina and Daphnia magna were tested with four Pasteuria genotypes using infection trials and an assay that determines the ability of the parasite to attach to the hosts esophagus. We find that attachment is not specific to host species but is specific to host genotype. This may suggest that alleles on the locus controlling attachment are shared among different host species that diverged 100 million year. However, in our trials, Pasteuria was never able to reproduce in nonnative host species, suggesting that Pasteuria infecting different host species are different varieties, each with a narrow host range. Our approach highlights the explanatory power of dissecting the steps of the infection process and resolves potentially conflicting reports on parasite host ranges.

  7. Dinucleotide composition in animal RNA viruses is shaped more by virus family than host species. (United States)

    Di Giallonardo, Francesca; Schlub, Timothy E; Shi, Mang; Holmes, Edward C


    Viruses use the cellular machinery of their hosts for replication. It has therefore been proposed that the nucleotide and dinucleotide composition of viruses should match that of their host species. If upheld, it may then be possible to use dinucleotide composition to predict the true host species of viruses sampled in metagenomic surveys. However, it is also clear that different taxonomic groups of viruses tend to have distinctive patterns of dinucleotide composition that may be independent of host species. To determine the relative strength of the effect of host versus virus family in shaping dinucleotide composition we performed a comparative analysis of 20 RNA virus families from 15 host groupings, spanning two animal phyla and more than 900 virus species. In particular, we determined the odds ratios for the 16 possible dinucleotides and performed a discriminant analysis to evaluate the capability of virus dinucleotide composition to predict the correct virus family or host taxon from which it was isolated. Notably, while 81% of the data analyzed here were predicted to the correct virus family, only 62% of these data were predicted to their correct subphylum/class host, and a mere 32% to their correct mammalian order. Similarly, dinucleotide composition has a weak predictive power for different hosts within individual virus families. We therefore conclude that dinucleotide composition is generally uniform within a virus family but less well reflects that of its host species. This has obvious implications for attempts to accurately predict host species from virus genome sequences alone.

  8. Considering extinction of dependent species during translocation, ex situ conservation, and assisted migration of threatened hosts. (United States)

    Moir, Melinda L; Vesk, Peter A; Brennan, Karl E C; Poulin, Robert; Hughes, Lesley; Keith, David A; McCarthy, Michael A; Coates, David J


    Translocation, introduction, reintroduction, and assisted migrations are species conservation strategies that are attracting increasing attention, especially in the face of climate change. However, preventing the extinction of the suite of dependent species whose host species are threatened is seldom considered, and the effects on dependent species of moving threatened hosts are unclear. There is no published guidance on how to decide whether to move species, given this uncertainty. We examined the dependent-host system of 4 disparate taxonomic groups: insects on the feather-leaf banksia (Banksia brownii), montane banksia (B. montana), and Stirling Range beard heath (Leucopogon gnaphalioides); parasites of wild cats; mites and ticks on Duvaucel's gecko (Hoplodactylus duvaucelii) and tuatara (Sphenodon punctatus); and internal coccidian parasites of Cirl Bunting (Emberiza cirlus) and Hihi (Notiomystis cincta). We used these case studies to demonstrate a simple process for use in species- and community-level assessments of efforts to conserve dependents with their hosts. The insects dependent on Stirling Range beard heath and parasites on tigers (Panthera tigris) appeared to represent assemblages that would not be conserved by ex situ host conservation. In contrast, for the cases of dependent species we examined involving a single dependent species (internal parasites of birds and the mite Geckobia naultina on Duvaucel's gecko), ex situ conservation of the host species would also conserve the dependent species. However, moving dependent species with their hosts may be insufficient to maintain viable populations of the dependent species, and additional conservation strategies such as supplementing populations may be needed.

  9. Codivergence and multiple host species use by fig wasp populations of the Ficus pollination mutualism

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    McLeish Michael J


    Full Text Available Abstract Background The interaction between insects and plants takes myriad forms in the generation of spectacular diversity. In this association a species host range is fundamental and often measured using an estimate of phylogenetic concordance between species. Pollinating fig wasps display extreme host species specificity, but the intraspecific variation in empirical accounts of host affiliation has previously been underestimated. In this investigation, lineage delimitation and codiversification tests are used to generate and discuss hypotheses elucidating on pollinating fig wasp associations with Ficus. Results Statistical parsimony and AMOVA revealed deep divergences at the COI locus within several pollinating fig wasp species that persist on the same host Ficus species. Changes in branching patterns estimated using the generalized mixed Yule coalescent test indicated lineage duplication on the same Ficus species. Conversely, Elisabethiella and Alfonsiella fig wasp species are able to reproduce on multiple, but closely related host fig species. Tree reconciliation tests indicate significant codiversification as well as significant incongruence between fig wasp and Ficus phylogenies. Conclusions The findings demonstrate more relaxed pollinating fig wasp host specificity than previously appreciated. Evolutionarily conservative host associations have been tempered by horizontal transfer and lineage duplication among closely related Ficus species. Independent and asynchronistic diversification of pollinating fig wasps is best explained by a combination of both sympatric and allopatric models of speciation. Pollinator host preference constraints permit reproduction on closely related Ficus species, but uncertainty of the frequency and duration of these associations requires better resolution.

  10. Is parasitoid acceptance of different host species dynamic? (United States)

    Choice of host individuals by parasitoids is dynamic, varying with physiological state and experience. In particular, female parasitoids with high egg loads and low life expectancy are more willing to accept low quality hosts than females with low egg loads and high life expectancy. However, studi...

  11. Are all species of Pseudorhabdosynochus strictly host specific? A molecular study. (United States)

    Schoelinck, Charlotte; Cruaud, Corinne; Justine, Jean-Lou


    Species of the diplectanid monogenean genus Pseudorhabdosynochus are strictly host-specific (specialist), with the exception of P. cyanopodus, which was reported in New Caledonia, South Pacific, from two host species, Epinephelus cyanopodus and E. chlorostigma. We sequenced the COI gene of both host fish species and of their monogeneans. Morphological identification and pairwise distances showed that the two fish species were distinct (difference 6.1-6.6%), but that their monogeneans were not (difference 0-1.5%). A morphological study of sclerotised parts showed that specimens of P. cyanopodus are similar in both fish. Most species of groupers and their associated Pseudorhabdosynochus species are from warm surface waters, but the two groupers E. cyanopodus and E. chlorostigma are usually caught in deep-sea on the outer slope of the coral reef. This suggests that acquisition of a less strict host specificity is an adaptation of P. cyanopodus to deep-sea hosts.

  12. Host-parasite interactions: Marine bivalve molluscs and protozoan parasites, Perkinsus species. (United States)

    Soudant, Philippe; E Chu, Fu-Lin; Volety, Aswani


    This review assesses and examines the work conducted to date concerning host and parasite interactions between marine bivalve molluscs and protozoan parasites, belonging to Perkinsus species. The review focuses on two well-studied host-parasite interaction models: the two clam species, Ruditapes philippinarum and R. decussatus, and the parasite Perkinsus olseni, and the eastern oyster, Crassostrea virginica, and the parasite Perkinsus marinus. Cellular and humoral defense responses of the host in combating parasitic infection, the mechanisms (e.g., antioxidant enzymes, extracellular products) employed by the parasite in evading host defenses as well as the role of environmental factors in modulating the host-parasite interactions are described.

  13. Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) use of Opuntia host species in Argentina (United States)

    A central aspect in biology and ecology is to determine the combination of factors that influence the distribution of species. In the case of herbivorous insects, the distribution of herbivorous species is necessarily associated with their host plants, a pattern often referred to as “host use”. Nove...

  14. Gene expression plasticity across hosts of an invasive scale insect species

    DEFF Research Database (Denmark)

    Christodoulides, Nicholas; Van Dam, Alex; Peterson, Daniel A.


    For plant-eating insects, we still have only a nascent understanding of the genetic basis of host-use promiscuity. Here, to improve that situation, we investigated host-induced gene expression plasticity in the invasive lobate lac scale insect, Paratachardina pseudolobata (Hemiptera: Keriidae). We...... of several recently published studies of other plant-eating insect species. Thus, across plant-eating insect species, there may be a common set of gene expression changes that enable host-use promiscuity....

  15. Dynamics of host plant use and species diversity in Polygonia butterflies (Nymphalidae). (United States)

    Weingartner, E; Wahlberg, N; Nylin, S


    The ability of insects to utilize different host plants has been suggested to be a dynamic and transient phase. During or after this phase, species can shift to novel host plants or respecialize on ancestral ones. Expanding the range of host plants might also be a factor leading to higher levels of net speciation rates. In this paper, we have studied the possible importance of host plant range for diversification in the genus Polygonia (Nymphalidae, Nymphalini). We have compared species richness between sistergroups in order to find out if there are any differences in number of species between clades including species that utilize only the ancestral host plants ('urticalean rosids') and their sisterclades with a broader (or in some cases potentially broader) host plant repertoire. Four comparisons could be made, and although these are not all phylogenetically or statistically independent, all showed clades including butterfly species using other or additional host plants than the urticalean rosids to be more species-rich than their sisterclade restricted to the ancestral host plants. These results are consistent with the theory that expansions in host plant range are involved in the process of diversification in butterflies and other phytophagous insects, in line with the general theory that plasticity may drive speciation.

  16. Plasmodium species: master renovators of their host cells. (United States)

    de Koning-Ward, Tania F; Dixon, Matthew W A; Tilley, Leann; Gilson, Paul R


    Plasmodium parasites, the causative agents of malaria, have developed elaborate strategies that they use to survive and thrive within different intracellular environments. During the blood stage of infection, the parasite is a master renovator of its erythrocyte host cell, and the changes in cell morphology and function that are induced by the parasite promote survival and contribute to the pathogenesis of severe malaria. In this Review, we discuss how Plasmodium parasites use the protein trafficking motif Plasmodium export element (PEXEL), protease-mediated polypeptide processing, a novel translocon termed the Plasmodium translocon of exported proteins (PTEX) and exomembranous structures to export hundreds of proteins to discrete subcellular locations in the host erythrocytes, which enables the parasite to gain access to vital nutrients and to evade the immune defence mechanisms of the host.

  17. Infection of non-host model plant species with the narrow-host-range Cacao swollen shoot virus. (United States)

    Friscina, Arianna; Chiappetta, Laura; Jacquemond, Mireille; Tepfer, Mark


    Cacao swollen shoot virus (CSSV) is a major pathogen of cacao (Theobroma cacao) in Africa, and long-standing efforts to limit its spread by the culling of infected trees have had very limited success. CSSV is a particularly difficult virus to study, as it has a very narrow host range, limited to several tropical tree species. Furthermore, the virus is not mechanically transmissible, and its insect vector can only be used with difficulty. Thus, the only efficient means to infect cacao plants that have been experimentally described so far are by particle bombardment or the agroinoculation of cacao plants with an infectious clone. We have genetically transformed three non-host species with an infectious form of the CSSV genome: two experimental hosts widely used in plant virology (Nicotiana tabacum and N. benthamiana) and the model species Arabidopsis thaliana. In transformed plants of all three species, the CSSV genome was able to replicate, and, in tobacco, CSSV particles could be observed by immunosorbent electron microscopy, demonstrating that the complete virus cycle could be completed in a non-host plant. These results will greatly facilitate the preliminary testing of CSSV control strategies using plants that are easy to raise and to transform genetically. © 2016 BSPP AND JOHN WILEY & SONS LTD.

  18. Host plant use among closely related Anaea butterfly species (Lepidoptera, Nymphalidae, Charaxinae

    Directory of Open Access Journals (Sweden)


    Full Text Available There is a great number of Charaxinae (Lepidoptera: Nymphalidae species in the tropics whose larvae feed on several plant families. However the genus Anaea is almost always associated with Croton species (Euphorbiaceae. This work describes patterns of host plant use by immature and adult abundance on different vertical strata of sympatric Anaea species in a forest of Southeastern Brazil. Quantitative samples of leaves were taken in April/1999 and May/2000 to collect eggs and larvae of four Anaea species on C.alchorneicarpus, C. floribundus and C. salutaris in a semideciduous forest. Sampled leaves were divided into three classes of plant phenological stage: saplings, shrubs and trees. The results showed that the butterfly species are segregating in host plant use on two scales: host plant species and plant phenological stages. C. alchorneicarpus was used by only one Anaea species, whereas C. floribundus was used by three species and C. salutaris by four Anaea species. There was one Anaea species concentrated on sapling, another on sapling/shrub and two others on shrub/tree leaves. Adults of Anaea were more frequent at canopy traps but there were no differences among species caught in traps at different vertical positions. This work supplements early studies on host plant use among Charaxinae species and it describes how a guild of closely related butterfly species may be organized in a complex tropical habitat.

  19. Host plant use among closely related Anaea butterfly species (Lepidoptera, Nymphalidae, Charaxinae

    Directory of Open Access Journals (Sweden)



    Full Text Available There is a great number of Charaxinae (Lepidoptera: Nymphalidae species in the tropics whose larvae feed on several plant families. However the genus Anaea is almost always associated with Croton species (Euphorbiaceae. This work describes patterns of host plant use by immature and adult abundance on different vertical strata of sympatric Anaea species in a forest of Southeastern Brazil. Quantitative samples of leaves were taken in April/1999 and May/2000 to collect eggs and larvae of four Anaea species on C.alchorneicarpus, C. floribundus and C. salutaris in a semideciduous forest. Sampled leaves were divided into three classes of plant phenological stage: saplings, shrubs and trees. The results showed that the butterfly species are segregating in host plant use on two scales: host plant species and plant phenological stages. C. alchorneicarpus was used by only one Anaea species, whereas C. floribundus was used by three species and C. salutaris by four Anaea species. There was one Anaea species concentrated on sapling, another on sapling/shrub and two others on shrub/tree leaves. Adults of Anaea were more frequent at canopy traps but there were no differences among species caught in traps at different vertical positions. This work supplements early studies on host plant use among Charaxinae species and it describes how a guild of closely related butterfly species may be organized in a complex tropical habitat.

  20. Molecular phylogenetic assessment of host range in five Dermanyssus species

    NARCIS (Netherlands)

    Roy, L.; Dowling, A.P.G.; Chauve, C.M.; Lesna, I.; Sabelis, M.W.; Buronfosse, T.


    Given that 14 out of the 25 currently described species of Dermanyssus Dugès, 1834, are morphologically very close to each another, misidentifications may occur and are suspected in at least some records. One of these 14 species is the red fowl mite, D. gallinae (De Geer, 1778), a blood parasite of

  1. Patterns of host adaptation in fly infecting Entomophthora species

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Jensen, Annette Bruun; Eilenberg, Jørgen

    effect? Here we examine closely related species within the Entomophthora muscae species complex: E. muscae s. str. infecting the common housefly Musca domestica and E. muscae s.l. strains infecting the cabbage fly Delia radicum. We use RNA-seq based comparative transcriptomics to unravel genetic...

  2. [Possibilities for identification of cryptic species of Chiroptera using host-specific ectoparasites]. (United States)

    Orlova, M V; Orlov, O L; Kruskop, S V; Bernikov, K A


    The possibility of identification of the sibling species of Chiroptera by the example of Myotis daubentonii Kuhl, 1817 and Myotis petax Hollister, 1912 by their host-specific ectoparasitic fauna is discussed. Their habitat limits are defined.

  3. Hybridization between two cestode species and its consequences for intermediate host range

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    Henrich Tina


    Full Text Available Abstract Background Many parasites show an extraordinary degree of host specificity, even though a narrow range of host species reduces the likelihood of successful transmission. In this study, we evaluate the genetic basis of host specificity and transmission success of experimental F1 hybrids from two closely related tapeworm species (Schistocephalus solidus and S. pungitii, both highly specific to their respective vertebrate second intermediate hosts (three- and nine-spined sticklebacks, respectively. Methods We used an in vitro breeding system to hybridize Schistocephalus solidus and S. pungitii; hybridization rate was quantified using microsatellite markers. We measured several fitness relevant traits in pure lines of the parental parasite species as well as in their hybrids: hatching rates, infection rates in the copepod first host, and infection rates and growth in the two species of stickleback second hosts. Results We show that the parasites can hybridize in the in vitro system, although the proportion of self-fertilized offspring was higher in the heterospecific breeding pairs than in the control pure parental species. Hybrids have a lower hatching rate, but do not show any disadvantages in infection of copepods. In fish, hybrids were able to infect both stickleback species with equal frequency, whereas the pure lines were only able to infect their normal host species. Conclusions Although not yet documented in nature, our study shows that hybridization in Schistocephalus spp. is in principle possible and that, in respect to their expanded host range, the hybrids are fitter. Further studies are needed to find the reason for the maintenance of the species boundaries in wild populations.

  4. Gryporhynchidae (Cestoda: Cyclophyllidea) in Mexico: species list, hosts, distribution and new records. (United States)

    Ortega-Olivares, Mirza P; García-Prieto, Luis; García-Varela, Martín


    As a result of this study, 8 new host (Botaurus lentiginosus for Glossocercus caribaensis and Valipora mutabilis; Egretta caerulea for Valipora minuta; Egretta thula for Glossocercus cyprinodontis; Egretta tricolor and Nycticorax nycticorax for Glossocercus caribaensis; Pelecanus occidentalis and Platalea ajaja for Paradilepis caballeroi) and 31 new locality records for gryporhynchid cestode species in Mexico are presented. With these data, the total number of species of this group of helminths in Mexico becomes 25 (19 named species and 6 unidentified taxa), which have been registered as parasites of fishes (47 host species) and (or) birds (20 host species). This information comes from 102 localities, pertaining to 20 of 32 Mexican states. Five of the 25 taxa have been exclusivelly collected in fishes, 7 in fish-eating birds, and 13 in both groups of hosts. The most frequent metacestodes found in Mexican fishes are the merocercoids of Cyclustera ralli, Valipora mutabilis, Parvitaenia cochlearii and Valipora campylancristrota; in adult stage, Glossocercus caribaensis was the species with the largest host spectrum, while Paradilepis caballeroi has the widest distribution range. The work includes parasite/host lists, as well as habitat, distribution, references and information on specimens' deposition.

  5. Host and habitat index for Phytophthora species in Oregon (United States)

    Everett Hansen; Paul Reeser; Wendy Sutton; Laura. Sims


    In this contribution we compile existing records from available sources of reliably identified Phytophthora species from forests and forest trees in Oregon, USA. A searchable version of this information may be found in the Forest Phytophthoras of the World Disease Finder (select USA-Oregon). We have included isolations from soil and streams in...

  6. No Effect of Host Species on Phenoloxidase Activity in a Mycophagous Beetle.

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    Vincent Formica

    Full Text Available Ecological immunology is an interdisciplinary field that helps elucidate interactions between the environment and immune response. The host species individuals experience have profound effects on immune response in many species of insects. However, this conclusion comes from studies of herbivorous insects even though species of mycophagous insects also inhabit many different host species. The goal of this study was to determine if fungal host species as well as individual, sex, body size, and host patch predict one aspect of immune function, phenoloxidase activity (PO. We sampled a metapopulation of Bolitotherus cornutus, a mycophagous beetle in southwestern Virginia. B. cornutus live on three species of fungus that differ in nutritional quality, social environment, and density. A filter paper phenoloxidase assay was used to quantify phenoloxidase activity. Overall, PO activity was significantly repeatable among individuals (0.57 in adult B. cornutus. While there was significant variance among individuals in PO activity, there were surprisingly no significant differences in PO activity among subpopulations, beetles living on different host species, or between the sexes; there was also no effect of body size. Our results suggest that other factors such as age, genotype, disease prevalence, or natal environment may be generating variance among individuals in PO activity.

  7. Do host species evolve a specific response to slave-making ants?

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    Delattre Olivier


    Full Text Available Abstract Background Social parasitism is an important selective pressure for social insect species. It is particularly the case for the hosts of dulotic (so called slave-making ants, which pillage the brood of host colonies to increase the worker force of their own colony. Such raids can have an important impact on the fitness of the host nest. An arms race which can lead to geographic variation in host defenses is thus expected between hosts and parasites. In this study we tested whether the presence of a social parasite (the dulotic ant Myrmoxenus ravouxi within an ant community correlated with a specific behavioral defense strategy of local host or non-host populations of Temnothorax ants. Social recognition often leads to more or less pronounced agonistic interactions between non-nestmates ants. Here, we monitored agonistic behaviors to assess whether ants discriminate social parasites from other ants. It is now well-known that ants essentially rely on cuticular hydrocarbons to discriminate nestmates from aliens. If host species have evolved a specific recognition mechanism for their parasite, we hypothesize that the differences in behavioral responses would not be fully explained simply by quantitative dissimilarity in cuticular hydrocarbon profiles, but should also involve a qualitative response due to the detection of particular compounds. We scaled the behavioral results according to the quantitative chemical distance between host and parasite colonies to test this hypothesis. Results Cuticular hydrocarbon profiles were distinct between species, but host species did not show a clearly higher aggression rate towards the parasite than toward non-parasite intruders, unless the degree of response was scaled by the chemical distance between intruders and recipient colonies. By doing so, we show that workers of the host and of a non-host species in the parasitized site displayed more agonistic behaviors (bites and ejections towards parasite

  8. Phylogenetic and chemotypic diversity of Periglandula species in eight new morning glory hosts (Convolvulaceae). (United States)

    Beaulieu, Wesley T; Panaccione, Daniel G; Ryan, Katy L; Kaonongbua, Wittaya; Clay, Keith


    Periglandula ipomoeae and P. turbinae (Ascomycota, Clavicipitaceae) are recently described fungi that form symbiotic associations with the morning glories (Convolvulaceae) Ipomoea asarifolia and Turbina corymbosa, respectively. These Periglandula species are vertically transmitted and produce bioactive ergot alkaloids in seeds of infected plants and ephemeral mycelia on the adaxial surface of young leaves. Whether other morning glories that contain ergot alkaloids also are infected by Periglandula fungi is a central question. Here we report on a survey of eight species of Convolvulaceae (Argyreia nervosa, I. amnicola, I. argillicola, I. gracilis, I. hildebrandtii, I. leptophylla, I. muelleri, I. pes-caprae) for ergot alkaloids in seeds and associated clavicipitaceous fungi potentially responsible for their production. All host species contained ergot alkaloids in four distinct chemotypes with concentrations of 15.8-3223.0 μg/g. Each chemotype was a combination of four or five ergot alkaloids out of seven alkaloids detected across all hosts. In addition, each host species exhibited characteristic epiphytic mycelia on adaxial surfaces of young leaves with considerable interspecific differences in mycelial density. We sequenced three loci from fungi infecting each host: the nuclear rDNA internal transcribed spacer region (ITS), introns of the translation factor 1-α gene (tefA) and the dimethylallyl-tryptophan synthase gene (dmaW), which codes for the enzyme that catalyzes the first step in ergot alkaloid biosynthesis. Phylogenetic analyses confirmed that these fungi are in the family Clavicipitaceae and form a monophyletic group with the two described Periglandula species. This study is the first to report Periglandula spp. from Asian, Australian, African and North American species of Convolvulaceae, including host species with a shrub growth form and host species occurring outside of the tropics. This study demonstrates that ergot alkaloids in morning glories

  9. Food plant and herbivore host species affect the outcome of intrinsic competition among parasitoid larvae

    NARCIS (Netherlands)

    Poelman, Erik H.; Gols, Rieta; Gumovsky, Alex V.; Cortesero, Anne-Marie; Dicke, Marcel; Harvey, Jeffrey A.


    1. In nature, several parasitoid species often exploit the same stages of a common herbivore host species and are able to coexist despite competitive interactions amongst them. Less is known about the direct effects of resource quality on intrinsic interactions between immature parasitoid stages. Th

  10. Molecular approaches identify known species, reveal cryptic species and verify host specificity of Chinese Philotrypesis (Hymenoptera: Pteromalidae). (United States)

    Zhou, Mei-Jiao; Xiao, Jin-Hua; Bian, Sheng-Nan; Li, Yan-Wei; Niu, Li-Ming; Hu, Hao-Yuan; Wu, Wen-Shan; Murphy, Robert W; Huang, Da-Wei


    Philotrypesis, a major component of the fig wasp community (Hymenoptera: Pteromalidae), is a model taxon for studying male fighting and mating behaviour. Its extreme sexual dimorphism and male polymorphism render species identification uncertain and in-depth research on its ecology, behaviour and other evolutionary topics challenging. The fig wasps' enclosed habitat within the syconia makes their mating behaviour inaccessible, to the extent of matching conspecific females and males. In this study, we combine morphological and molecular analyses to identify species of Philotrypesis sampled from south China and to associate their extraordinarily dimorphic genders and labile male morphologies. Morphological evaluations of females identify 22 species and 28 male morphs. The mitochondrial cytochrome c oxidase I and nuclear internal transcribed spacer 2 data detect 21 species using females, and 15 species among the males. Most of the males match the species as delimited by females. Both markers reveal cryptic species in P. quadrisetosa on Ficus vasculosa. Most species of wasps live on one species of fig but three species co-occur in two hosts (F. microcarpa and F. benjamina), which indicates host switching.

  11. Adaptive radiation of gall-inducing insects within a single host-plant species. (United States)

    Joy, Jeffrey B; Crespi, Bernard J


    Speciation of plant-feeding insects is typically associated with host-plant shifts, with subsequent divergent selection and adaptation to the ecological conditions associated with the new plant. However, a few insect groups have apparently undergone speciation while remaining on the same host-plant species, and such radiations may provide novel insights into the causes of adaptive radiation. We used mitochondrial and nuclear DNA to infer a phylogeny for 14 species of gall-inducing Asphondylia flies (Diptera: Cecidomyiidae) found on Larrea tridentata (creosote bush), which have been considered to be monophyletic based on morphological evidence. Our phylogenetic analyses provide strong support for extensive within-host plant speciation in this group, and it demonstrates that diversification has involved numerous shifts between different plant organs (leaves, buds, flowers, and stems) of the same host-plant species. Within-plant speciation of Asphondylia is thus apparently facilitated by the opportunity to partition the plant ecologically. One clade exhibits temporal isolation among species, which may have facilitated divergence via allochronic shifts. Using a novel method based on Bayesian reconstruction, we show that the rate of change in an ecomorphological trait, ovipositor length, was significantly higher along branches with inferred shifts between host-plant organs than along branches without such shifts. This finding suggests that Larrea gall midges exhibit close morphological adaptation to specific host-plant parts, which may mediate ecological transitions via disruptive selection.

  12. Climate driven range divergence among host species affects range-wide patterns of parasitism

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    Richard E. Feldman


    Full Text Available Species interactions like parasitism influence the outcome of climate-driven shifts in species ranges. For some host species, parasitism can only occur in that part of its range that overlaps with a second host species. Thus, predicting future parasitism may depend on how the ranges of the two hosts change in relation to each other. In this study, we tested whether the climate driven species range shift of Odocoileus virginianus (white-tailed deer accounts for predicted changes in parasitism of two other species from the family Cervidae, Alces alces (moose and Rangifer tarandus (caribou, in North America. We used MaxEnt models to predict the recent (2000 and future (2050 ranges (probabilities of occurrence of the cervids and a parasite Parelaphostrongylus tenuis (brainworm taking into account range shifts of the parasite’s intermediate gastropod hosts. Our models predicted that range overlap between A. alces/R. tarandus and P. tenuis will decrease between 2000 and 2050, an outcome that reflects decreased overlap between A. alces/R. tarandus and O. virginianus and not the parasites, themselves. Geographically, our models predicted increasing potential occurrence of P. tenuis where A. alces/R. tarandus are likely to decline, but minimal spatial overlap where A. alces/R. tarandus are likely to increase. Thus, parasitism may exacerbate climate-mediated southern contraction of A. alces and R. tarandus ranges but will have limited influence on northward range expansion. Our results suggest that the spatial dynamics of one host species may be the driving force behind future rates of parasitism for another host species.

  13. Differential Host Plant-Associated Genetic Variation Between Sympatric Mite Species of the Genus Oligonychus (Acari: Tetranychidae). (United States)

    Guzman-Valencia, Stephanie; Santillán-Galicia, Ma Teresa; Guzmán-Franco, Ariel W; Vega-Muñoz, Ricardo


    Adaptation to different host plants can lead to host-associated differentiation (HAD). The mites Oligonychus perseae and Oligonychus punicae have a broad range of host plants, but, to date, records of them coexisting sympatrically had only been reported on avocado. However, our field observations showed both species coexisting on host plants other than avocado. The lack of previous records of these mites on the host plants studied here suggests only recent divergence to new host plant species. Previous studies showed that O. punicae had a limited migration capacity compared with O. perseae, suggesting that O. punicae is more likely to develop a close host plant relationship leading to HAD. Adults of both species were collected from trees hosting both mite species. Three genera of host plants considered were Persea, Salix, and Alnus; two species within one genus were Alnus jorullensis and Alnus acuminata; and three varieties within one species were Persea americana var. Fuerte, var. Hass, and var. Criollo, a noncommercial variety. Using sequence data from a segment of the mitochondrial cytochrome oxidase subunit I, the phylogenetic relationships and genetic population structure of both mite species in relation to the host plant were determined. Oligonychus perseae populations showed a significant population structure in relation to host plant at the species and genus level, but there was no effect of variety. In contrast, host plant explained none of the genetic variation among O. punicae populations. The potential role of coexistence mechanisms in the contrasting genetic population structure of both mite species is discussed.

  14. Effects of Host Plant Factors on the Bacterial Communities Associated with Two Whitefly Sibling Species. (United States)

    Su, Ming-Ming; Guo, Lei; Tao, Yun-Li; Zhang, You-Jun; Wan, Fang-Hao; Chu, Dong


    Although discrepancy in the specific traits and ecological characteristics of Bemisia tabaci between species are partially attributed to the B. tabaci-associated bacteria, the factors that affect the diversity of B. tabaci-associated bacteria are not well-understood. We used the metagenomic approach to characterize the B. tabaci-associated bacterial community because the approach is an effective tool to identify the bacteria. To investigate the effects of the host plant and a virus, tomato yellow leaf curl virus (TYLCV), on the bacterial communities of B. tabaci sibling species B and Q, we analyzed the bacterial communities associated with whitefly B and Q collected from healthy cotton, healthy tomato, and TYLCV-infected tomato. The analysis used miseq-based sequencing of a variable region of the bacterial 16S rDNA gene. For the bacteria associated with B. tabaci, we found that the influence of the host plant species was greater than that of the whitefly cryptic species. With further analysis of host plants infected with the TYLCV, the virus had no significant effects on the B. tabaci-associated bacterial community. The effects of different plant hosts and TYLCV-infection on the diversity of B. tabaci-associated bacterial communities were successfully analyzed in this study. To explain why B. tabaci sibling species with different host ranges differ in performance, the analysis of the bacterial community may be essential to the explanation.

  15. Toxocara cati (Schrank, 1788 (Nematoda, Ascarididae in different wild feline species in Brazil: new host records

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    Moisés Gallas


    Full Text Available This is the first detailed description of Toxocara cati parasitizing felines in South America. Seventeen run over wild felines (Leopardus colocolo, Leopardus geoffroyi, Leopardus tigrinus, and Puma yagouaroundi were collected from different towns in the State of Rio Grande do Sul, Brazil. The morphometry of males and females allowed the identification of specimens as being T. cati. The helminths were found in the stomach and intestine of hosts with prevalences of 66.6% in L. colocolo, L. geoffroyi, and L. tigrinus; and 60% in P. yagouaroundi. The ecological parameters were calculated for each host and L. colocolo had the highest infection intensity (22.5 helminths/host. This is the first report of T. cati parasitizing four wild felines species in southern Brazil, besides a new record of this parasite for two host species.

  16. Evaluation of 31 potential biofumigant brassicaceous plants as hosts for three meloiodogyne species. (United States)

    Edwards, Scott; Ploeg, Antoon


    Brassicaceous cover crops can be used for biofumigation after soil incorporation of the mowed crop. This strategy can be used to manage root-knot nematodes (Meloidogyne spp.), but the fact that many of these crops are host to root-knot nematodes can result in an undesired nematode population increase during the cultivation of the cover crop. To avoid this, cover crop cultivars that are poor or nonhosts should be selected. In this study, the host status of 31 plants in the family Brassicaceae for the three root-knot nematode species M. incognita, M. javanica, and M. hapla were evaluated, and compared with a susceptible tomato host in repeated greenhouse pot trials. The results showed that M. incognita and M. javanica responded in a similar fashion to the different cover cultivars. Indian mustard (Brassica juncea) and turnip (B. rapa) were generally good hosts, whereas most oil radish cultivars (Raphanus. sativus ssp. oleiferus) were poor hosts. However, some oil radish cultivars were among the best hosts for M. hapla. The arugula (Eruca sativa) cultivar Nemat was a poor host for all three nematode species tested. This study provides important information for chosing a cover crop with the purpose of managing root-knot nematodes.

  17. Alternative mechanisms of increased eggshell hardness of avian brood parasites relative to host species (United States)

    Igic, Branislav; Braganza, Kim; Hyland, Margaret M.; Silyn-Roberts, Heather; Cassey, Phillip; Grim, Tomas; Rutila, Jarkko; Moskát, Csaba; Hauber, Mark E.


    Obligate brood parasitic birds lay their eggs in nests of other species and parasite eggs typically have evolved greater structural strength relative to host eggs. Increased mechanical strength of the parasite eggshell is an adaptation that can interfere with puncture ejection behaviours of discriminating hosts. We investigated whether hardness of eggshells is related to differences between physical and chemical traits from three different races of the parasitic common cuckoo Cuculus canorus, and their respective hosts. Using tools developed for materials science, we discovered a novel correlate of increased strength of parasite eggs: the common cuckoo's egg exhibits a greater microhardness, especially in the inner region of the shell matrix, relative to its host and sympatric non-host species. We then tested predictions of four potential mechanisms of shell strength: (i) increased relative thickness overall, (ii) greater proportion of the structurally harder shell layers, (iii) higher concentration of inorganic components in the shell matrix, and (iv) elevated deposition of a high density compound, MgCO3, in the shell matrix. We confirmed support only for hypothesis (i). Eggshell characteristics did not differ between parasite eggs sampled from different host nests in distant geographical sites, suggesting an evolutionarily shared microstructural mechanism of stronger parasite eggshells across diverse host-races of brood parasitic cuckoos. PMID:21561966

  18. Evaluation of 31 Potential Biofumigant Brassicaceous Plants as Hosts for Three Meloiodogyne Species (United States)

    Edwards, Scott; Ploeg, Antoon


    Brassicaceous cover crops can be used for biofumigation after soil incorporation of the mowed crop. This strategy can be used to manage root-knot nematodes (Meloidogyne spp.), but the fact that many of these crops are host to root-knot nematodes can result in an undesired nematode population increase during the cultivation of the cover crop. To avoid this, cover crop cultivars that are poor or nonhosts should be selected. In this study, the host status of 31 plants in the family Brassicaceae for the three root-knot nematode species M. incognita, M. javanica, and M. hapla were evaluated, and compared with a susceptible tomato host in repeated greenhouse pot trials. The results showed that M. incognita and M. javanica responded in a similar fashion to the different cover cultivars. Indian mustard (Brassica juncea) and turnip (B. rapa) were generally good hosts, whereas most oil radish cultivars (Raphanus. sativus ssp. oleiferus) were poor hosts. However, some oil radish cultivars were among the best hosts for M. hapla. The arugula (Eruca sativa) cultivar Nemat was a poor host for all three nematode species tested. This study provides important information for chosing a cover crop with the purpose of managing root-knot nematodes. PMID:25276003

  19. Species and sexual differences in behavioural responses of a specialist and generalist parasitoid species to host-related volatiles. (United States)

    Ngumbi, E; Fadamiro, H


    The relationship between the degree of specialization of parasitoids and their responses to host-related volatiles is an important and current evolutionary question. Specialist parasitoids which have evolved to attack fewer host species are predicted to be more responsive to host-related volatiles than generalists. We tested the above prediction by comparing behavioural responses of both sexes of two parasitoids (Hymenoptera: Braconidae) with different degrees of host specificity, Microplitis croceipes (Cresson) (specialist) and Cotesia marginiventris (generalist), to different suites of synthetic host-related volatile compounds. The compounds tested at two doses (1 and 100 μg) include two green leaf volatiles (GLVs: hexanal and (Z)-3-hexen-1-ol) and four herbivore-induced plant volatiles (HIPVs: (Z)-3-hexenyl acetate, linalool, (Z)-3-hexenyl butyrate and (E,E)-α-farnesene). Two hypotheses were tested: (i) M. croceipes (specialist) would show relatively greater behavioural responses to the HIPVs, whereas C. marginiventris (generalist) would show greater behavioural responses to the GLVs, and (ii) females of both species would show greater responses than conspecific males to the host-related volatiles. At the low dose (1 μg), females of the specialist showed significantly greater responses than females of the generalist to three of the tested HIPVs, (Z)-3-hexenyl acetate, linalool and (Z)-3-hexenyl butyrate. In contrast, females of the generalist showed relatively greater responses to the GLVs. The same trends were recorded at the high dose but fewer significant differences were detected. In general, similar results were recorded for males, with the exception of linalool (an HIPV) which elicited significantly greater response in the generalist than the specialist. Comparing the sexes, females of both species showed greater responses than conspecific males to most of the tested volatiles. The ecological significance of these findings is discussed.

  20. Cross-Species Virus-Host Protein-Protein Interactions Inhibiting Innate Immunity (United States)


    diseases are a regular occurrence globally (Figure 1). The Zika virus is the latest example gaining widespread attention. Many of the (re-)emerging...8725 John J. Kingman Road, MS 6201 Fort Belvoir, VA 22060-6201 T E C H N IC A L R E P O R T DTRA-TR-16-79 Cross-species virus -host...Cross-species virus -host protein-protein interactions inhibiting innate immunity What are the major goals of the project? List the major goals of

  1. Stress responses in Streptococcus species and their effects on the host. (United States)

    Nguyen, Cuong Thach; Park, Sang-Sang; Rhee, Dong-Kwon


    Streptococci cause a variety of diseases, such as dental caries, pharyngitis, meningitis, pneumonia, bacteremia, endocarditis, erysipelas, and necrotizing fasciitis. The natural niche of this genus of bacteria ranges from the mouth and nasopharynx to the skin, indicating that the bacteria will inevitably be subjected to environmental changes during invasion into the host, where it is exposed to the host immune system. Thus, the Streptococcus-host interaction determines whether bacteria are cleared by the host's defenses or whether they survive after invasion to cause serious diseases. If this interaction was to be deciphered, it could aid in the development of novel preventive and therapeutic agents. Streptococcus species possess many virulent factors, such as peroxidases and heat-shock proteins (HSPs), which play key roles in protecting the bacteria from hostile host environments. This review will discuss insights into the mechanism(s) by which streptococci adapt to host environments. Additionally, we will address how streptococcal infections trigger host stress responses; however, the mechanism by which bacterial components modulate host stress responses remains largely unknown.

  2. Variations in Host Preference among and within Populations of Heterodera trifolii and Related Species. (United States)

    Wang, S; Riggs, R D


    Seven populations of Heterodera trifolii from Arkansas, Kentucky, Pennsylvania, and Australia plus 3 or 4 single-cyst isolates (SCI) from each population were tested for reproduction on seven species of plants to compare the host preferences among and within populations. Common lespedeza, Kummerowia striata cv. Kobe, was a good host for all populations and isolates. Therefore, a plant was considered to be a host if the number of females produced on it was 10% or more of the number on Kobe. All seven populations reproduced on Trifolium repens and T. pratense. None reproduced on Beta vulgaris or Glycine max. One single-cyst isolate from the Australian population produced a few females on T. pratense. The Australian population maintained on carnation, Dianthus caryophyllus, produced females on carnation but not on curly dock, Rumex crispus. However, its subpopulation maintained on T. repens produced females on R. crispus but not on carnation. Four of the other six populations produced females on R. crispus, and four produced females on carnation. Differences in host range were observed among seven of the mother populations and their SCI, and among isolates within each population. Five host range patterns were found in populations and SCI of H. trifolii. Significant quantitative differences occurred among populations in the numbers of females on most hosts, between isolates and their original populations, and among isolates from the same population. SCI selected from white clover produced fewer females on a series of test hosts and had host ranges the same as or narrower than those of the original populations. However, SCI selected from Kobe lespedeza had more females on some hosts and had host ranges the same as or wider than those of the original populations. The host ranges of all populations and SCI of H. trifolii were different from those of populations and SCI of race 3 of H. glycines and H. lespedezae.

  3. Frequent cross-species transmission of parvoviruses among diverse carnivore hosts (United States)

    Allison, Andrew B.; Kohler, Dennis J.; Fox, Karen A.; Brown, Justin D.; Gerhold, Richard W.; Shearn-Bochsler, Valerie I.; Dubovi, Edward J.; Parrish, Colin R.; Holmes, Edward C.


    Although parvoviruses are commonly described in domestic carnivores, little is known about their biodiversity in nondomestic species. A phylogenetic analysis of VP2 gene sequences from puma, coyote, gray wolf, bobcat, raccoon, and striped skunk revealed two major groups related to either feline panleukopenia virus (“FPV-like”) or canine parvovirus (“CPV-like”). Cross-species transmission was commonplace, with multiple introductions into each host species but, with the exception of raccoons, relatively little evidence for onward transmission in nondomestic species.

  4. Discrimination of the Social Parasite Ectatomma parasiticum by Its Host Sibling Species (E. tuberculatum

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    Renée Fénéron


    Full Text Available Among social parasites, workerless inquilines entirely depend on their host for survival and reproduction. They are usually close phylogenetic relatives of their host, which raises important questions about their evolutionary history and mechanisms of speciation at play. Here we present new findings on Ectatomma parasiticum, the only inquiline ant described in the Ectatomminae subfamily. Field data confirmed its rarity and local distribution in a facultative polygynous population of E. tuberculatum in Mexico. Genetic analyses demonstrated that the parasite is a sibling species of its host, from which it may have diverged recently. Polygyny is suggested to have favored the evolution of social parasite by sympatric speciation. Nevertheless, host workers from this population were able to discriminate parasites from their conspecifics. They treated the parasitic queens either as individuals of interest or as intruders, depending on their colonial origin, probably because of the peculiar chemical profile of the parasites and/or their reproductive status. We suggest that E. parasiticum could have conserved from its host sibling species the queen-specific substances that produce attracting and settling effect on workers, which, in return, would increase the probability to be detected. This hypothesis could explain the imperfect social integration of the parasite into host colonies.

  5. Association of host and microbial species diversity across spatial scales in desert rodent communities.

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    Yoni Gavish

    Full Text Available Relationships between host and microbial diversity have important ecological and applied implications. Theory predicts that these relationships will depend on the spatio-temporal scale of the analysis and the niche breadth of the organisms in question, but representative data on host-microbial community assemblage in nature is lacking. We employed a natural gradient of rodent species richness and quantified bacterial communities in rodent blood at several hierarchical spatial scales to test the hypothesis that associations between host and microbial species diversity will be positive in communities dominated by organisms with broad niches sampled at large scales. Following pyrosequencing of rodent blood samples, bacterial communities were found to be comprised primarily of broad niche lineages. These communities exhibited positive correlations between host diversity, microbial diversity and the likelihood for rare pathogens at the regional scale but not at finer scales. These findings demonstrate how microbial diversity is affected by host diversity at different spatial scales and suggest that the relationships between host diversity and overall disease risk are not always negative, as the dilution hypothesis predicts.

  6. Marine protected areas facilitate parasite populations among four fished host species of central Chile. (United States)

    Wood, Chelsea L; Micheli, Fiorenza; Fernández, Miriam; Gelcich, Stefan; Castilla, Juan Carlos; Carvajal, Juan


    1. Parasites comprise a substantial proportion of global biodiversity and exert important ecological influences on hosts, communities and ecosystems, but our knowledge of how parasite populations respond to human impacts is in its infancy. 2. Here, we present the results of a natural experiment in which we used a system of highly successful marine protected areas and matched open-access areas in central Chile to assess the influence of fishing-driven biodiversity loss on parasites of exploited fish and invertebrate hosts. We measured the burden of gill parasites for two reef fishes (Cheilodactylus variegatus and Aplodactylus punctatus), trematode parasites for a keyhole limpet (Fissurella latimarginata), and pinnotherid pea crab parasites for a sea urchin (Loxechinus albus). We also measured host density for all four hosts. 3. We found that nearly all parasite species exhibited substantially greater density (# parasites m(-2)) in protected than in open-access areas, but only one parasite species (a gill monogenean of C. variegatus) was more abundant within hosts collected from protected relative to open-access areas. 4. These data indicate that fishing can drive declines in parasite abundance at the parasite population level by reducing the availability of habitat and resources for parasites, but less commonly affects the abundance of parasites at the infrapopulation level (within individual hosts). 5. Considering the substantial ecological role that many parasites play in marine communities, fishing and other human impacts could exert cryptic but important effects on marine community structure and ecosystem functioning via reductions in parasite abundance.

  7. Life history of Paracoccus marginatus (Hemiptera: Pseudococcidae) on four host plant species under laboratory conditions. (United States)

    Amarasekare, Kaushalya G; Mannion, Catharine M; Osborne, Lance S; Epsky, Nancy D


    Life history of the mealybug, Paracoccus marginatus Williams and Granara de Willink, on three ornamental plants [Hibiscus rosa-sinensis L., Acalypha wilkesiana (Muell.-Arg.), and Plumeria rubra L.] and one weed species (Parthenium hysterophorus L.) was studied under laboratory conditions. Mealybugs were able to develop, survive, and reproduce on all four hosts; however, there were differences in the life history parameters. Adult females that developed on acalypha and parthenium emerged approximately 1 d earlier than those that developed on hibiscus and plumeria. Adult males had a longer developmental time on plumeria than on the other hosts. Survival of first- and second-instar nymphs and cumulative adult survival were lowest on plumeria. Longevity was not affected by hosts for males and females and averaged 2.3 +/- 0.1 and 21.2 +/- 0.1 d, respectively. On plumeria, 58.9 +/- 1.7% of the adults were females, which was a higher female percentage than on the other hosts. No egg production occurred in virgin females. Prereproductive and reproductive periods of the females were not affected by hosts and averaged 6.3 +/- 0.1 and 11.2 +/- 0.1 d, respectively. Mean fecundity of 186.3 +/- 1.8 eggs on plumeria was lower than on the other three plant species. Life history parameters of P. marginatus on hibiscus, acalypha, plumeria, and parthenium show its ability to develop, survive, and reproduce on a wide variety of plant species.

  8. Host-parasite interaction between crustaceans of six fish species from the Brazilian Amazon

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    Huann Carllo Gentil Vasconcelos


    Full Text Available Host-parasite interactions between crustaceans and six fish species (Psectrogaster falcata, Ageneiosus ucayalensis, Acestrorhynchus falcirostris, Hemiodus unimaculatus, Serrasalmus gibbus and Geophagus proximus from a reservoir in eastern Amazon, northern Brazil, were investigated. Eight hundred and seventy-eight parasites belonging to three crustacean species, Excorallana berbicensis, Argulus chicomendesi and Ergasilus turucuyus, which parasitized the hosts’ mouth, gills and tegument, were collected from 295 fish and examined. High infestation levels were caused by E. berbicensis on the body surface of the hosts. Excorallana berbicensis showed aggregate dispersion, except in S. gibbus, while E. turucuyus showed random dispersion in A. falcirostris. The host’s sex did not influence infestation by E. berbicensis, and high parasitism failed to affect the body conditions of the fish. In the case of some hosts, rainfall rates, temperature, dissolved oxygen levels and water pH affected the prevalence and abundance of E. berbicensis, the dominant parasite species. Results revealed that the environment and life-style of the hosts were determining factors in infestations by parasites. Current assay is the first report on E. berbicensis for the six hosts, as well as on A. chicomendesi for G. proximus and P. falcata.

  9. Cellulase in Anoplophora glabripennis adults emerging from different host tree species

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    LI Xiao-juan; YAN Xiong-fei; LUO You-qing; TIAN Gui-fang; SUN Hong


    In order to investigate different kinds of cellulase in insect pests, we selected male and female adults of Anoplophora glabripennis (Motschulsky) emerging from four different host species (Populus alba vat. pyramidalis, P. nigra vat. thevestina (Dode)Bean., P. simonii × P. pyramidliscr cv. Opera 8277 Hsu. and Salix matsudana f. lobato-glandulosa) as our research material. The enzyme activitives of three kinds of cellulase in the intestines of the adult insects were measured. The Cx-cellulase isozymes were detected with a CMC-incorporated polyacrylamide gel. The results show that: there are no statistically significant differences between the enzyme activities of males and females emerging from the different host species. The order of magnitude in activity is:Cx-cellulase >β-glycosidase > C1-cellulase. When the adults emerge from the same host species, there are no statistically significant differences between male and female enzyme activities ofβ-glycosidase and C1-cellulase, but the enzyme activity of Cx-cellulase of males is clearly higher than that of females. The patterns and migration of Cx-cellulase isozymes of males and females emerging from different hosts trees are clearly not different, and neither are they different when emerging from the same hosts.

  10. (macro- Evolutionary ecology of parasite diversity: From determinants of parasite species richness to host diversification

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    Serge Morand


    Full Text Available The present review summarized the factors or determinants that may explain parasite diversity among host species and the consequences of this parasite diversity on the evolution of host-life history traits. As host–parasite interactions are asymmetrical exploited–exploiter relationships, ecological and epidemiological theories produce hypotheses to find the potential determinants of parasite species richness, while life-history theory helps for testing potential consequences on parasite diversity on the evolution of hosts. This review referred only to studies that have specifically controlled or took into account phylogenetic information illustrated with parasites of mammals. Several points needing more investigation were identified with a special emphasis to develop the metabolic theory of epidemiology.

  11. Species of Mycosphaerellaceae and Teratosphaeriaceae on native Myrtaceae in Uruguay: evidence of fungal host jumps. (United States)

    Pérez, C A; Wingfield, M J; Altier, N; Blanchette, R A


    Mycosphaerella species are well-known causal agents of leaf diseases on many economically and ecologically important plant species. In Uruguay, a relatively large number of Mycosphaerellaceae and Teratosphaeriaceae are found on Eucalyptus, but nothing is known of these fungi on native Myrtaceae. The aim of this study was to identify Mycosphaerellaceae and Teratosphaeriaceae species associated with leaf diseases on native Myrtaceae in Uruguay and to consider whether host jumps by the pathogen from introduced Eucalyptus to native Myrtaceae have occurred. Several native forests throughout the country were surveyed with special attention given to those located close to Eucalyptus plantations. Five species belonging to the Mycosphaerellaceae and Teratosphaeriaceae clades were found on native Myrtaceous trees and three of these had previously been reported on Eucalyptus in Uruguay. Those occurring both on Eucalyptus and native Myrtaceae included Pallidocercospora heimii, Pseudocercospora norchiensis, and Teratosphaeria aurantia. In addition, Mycosphaerella yunnanensis, a species known to occur on Eucalyptus but not previously recorded in Uruguay, was found on leaves of two native Myrtaceous hosts. Because most of these species occur on Eucalyptus in countries other than Uruguay, it appears that they were introduced in this country and have adapted to be able to infect native Myrtaceae. These apparent host jumps have the potential to result in serious disease problems and they should be carefully monitored.

  12. [Quality of different aphids species as hosts for the parasitoid Aphidius ervi Haliday (Hymenoptera: Braconidae: Aphidiinae)]. (United States)

    Sidney, Lívia A; Bueno, Vanda H P; Lins, Juracy C; Silva, Diego B; Sampaio, Marcus V


    The suitability of Macrosiphum euphorbiae (Thomas), Aulacorthum solani (Kaltenbach) and Acyrthosiphon kondoi Shinji (Hemiptera: Aphididae) as hosts for the aphid parasitoid Aphidius ervi Haliday was evaluated by assessing host size, host preference, and host quality. Tests were carried out in an environmental chamber at 22±1ºC, 70±10% RH and 12h photophase. Replicates (11) consisted of one 24h-old mated female of A. ervi without a previous oviposition experience. Female was released into a Petri dish (5 cm) with 20 2nd and 3rd instars of one of each aphid species tested on a leaf disc of the host plant onto a 1% water-agar layer. Parasitoid emergency was lower in A. kondoi (78.7%) compared to M. euphorbiae (92.2%) and A. solani (91.7%). Acyrthosiphon kondoi (0.36 mm) was the smallest host. The parasitoid showed preference (74.0% parasitism) for M. euphorbiae, the largest host (hind tibia length=0.73 mm), which in turn yielded larger A. ervi females (0.75 mm).

  13. Multi locus sequence typing of Chlamydia reveals an association between Chlamydia psittaci genotypes and host species.

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    Yvonne Pannekoek

    Full Text Available Chlamydia comprises a group of obligate intracellular bacterial parasites responsible for a variety of diseases in humans and animals, including several zoonoses. Chlamydia trachomatis causes diseases such as trachoma, urogenital infection and lymphogranuloma venereum with severe morbidity. Chlamydia pneumoniae is a common cause of community-acquired respiratory tract infections. Chlamydia psittaci, causing zoonotic pneumonia in humans, is usually hosted by birds, while Chlamydia abortus, causing abortion and fetal death in mammals, including humans, is mainly hosted by goats and sheep. We used multi-locus sequence typing to asses the population structure of Chlamydia. In total, 132 Chlamydia isolates were analyzed, including 60 C. trachomatis, 18 C. pneumoniae, 16 C. abortus, 34 C. psittaci and one of each of C. pecorum, C. caviae, C. muridarum and C. felis. Cluster analyses utilizing the Neighbour-Joining algorithm with the maximum composite likelihood model of concatenated sequences of 7 housekeeping fragments showed that C. psittaci 84/2334 isolated from a parrot grouped together with the C. abortus isolates from goats and sheep. Cluster analyses of the individual alleles showed that in all instances C. psittaci 84/2334 formed one group with C. abortus. Moving 84/2334 from the C. psittaci group to the C. abortus group resulted in a significant increase in the number of fixed differences and elimination of the number of shared mutations between C. psittaci and C. abortus. C. psittaci M56 from a muskrat branched separately from the main group of C. psittaci isolates. C. psittaci genotypes appeared to be associated with host species. The phylogenetic tree of C. psittaci did not follow that of its host bird species, suggesting host species jumps. In conclusion, we report for the first time an association between C. psittaci genotypes with host species.

  14. Morphological and molecular analyses support the existence of host-specific Peronospora species infecting Chenopodium. (United States)

    Choi, Young-Joon; Denchev, Cvetomir M; Shin, Hyeon-Dong


    About 20 species of Peronospora have been reported to cause downy mildew on Chenopodium, but, particularly in plant pathology literature, only one species, P. farinosa, is considered to be involved. We performed sequence analysis of the ITS rDNA to reveal the phylogenetic relationships of Peronospora specimens from five species of Chenopodium, viz. C. album, C. ambrosioides, C. bonus-henricus, C. hybridum, and C. polyspermum. The five clades corresponded to particular Chenopodium species, and showed a high level of sequence divergence. Differences in the morphology of the conidia and ultimate branchlets also supported the separation of the five groups at the host species level. These results suggest that the names P. variabilis, P. boni-henrici, P. chenopodii, and P. chenopodii-polyspermi should be used for the four downy mildew pathogens specific to C. album, C. bonus-henricus, C. hybridum, and C. polyspermum, respectively. The Peronospora on C. ambrosioides was found to be an independent species.

  15. Host life history strategy, species diversity, and habitat influence Trypanosoma cruzi vector infection in Changing landscapes.

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    Nicole L Gottdenker

    Full Text Available BACKGROUND: Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama. METHODOLOGY/PRINCIPAL FINDINGS: R. pallescens vectors (N = 643 were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3% vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3% dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as r(max, the maximum intrinsic rate of population increase, and habitat type (forest fragments and peridomiciliary sites were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of r(max were positively associated with higher vector infection rate at a site. CONCLUSIONS/SIGNIFICANCE: In this study, anthropogenic landscape disturbance increased vector infection with T

  16. Ultrastructural characteristics of nurse cell-larva complex of four species of Trichinella in several hosts

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    Sacchi L.


    Full Text Available The nurse cell-larva complex of nematodes of the genus Trichinella plays an Important role in the survival of the larva in decaying muscles, frequently favouring the transmission of the parasite in extreme environmental conditions. The ultrastructure of the nurse cell-larva complex in muscles from different hosts infected with T. nativa (a walrus and a polar bear, T. spiralis (horses and humans, T. pseudospiralis (a laboratory mouse and T. papuae (a laboratory mouse were examined. Analysis with transmission electron microscope showed that the typical nurse cell structure was present in all examined samples, irrespective of the species of larva, of the presence of a collagen capsule, of the age of infection and of the host species, suggesting that there exists a molecular mechanism that in the first stage of larva invasion is similar for encapsulated and non-encapsulated species.

  17. Ecological and genetic differences between Cacopsylla melanoneura (Hemiptera, Psyllidae populations reveal species host plant preference.

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    Valeria Malagnini

    Full Text Available The psyllid Cacopsylla melanoneura is considered one of the vectors of 'Candidatus Phytoplasma mali', the causal agent of apple proliferation disease. In Northern Italy, overwintered C. melanoneura adults reach apple and hawthorn around the end of January. Nymph development takes place between March and the end of April. The new generation adults migrate onto conifers around mid-June and come back to the host plant species after overwintering. In this study we investigated behavioural differences, genetic differentiation and gene flow between samples of C. melanoneura collected from the two different host plants. Further analyses were performed on some samples collected from conifers. To assess the ecological differences, host-switching experiments were conducted on C. melanoneura samples collected from apple and hawthorn. Furthermore, the genetic structure of the samples was studied by genotyping microsatellite markers. The examined C. melanoneura samples performed better on their native host plant species. This was verified in terms of oviposition and development of the offspring. Data resulting from microsatellite analysis indicated a low, but statistically significant difference between collected-from-apple and hawthorn samples. In conclusion, both ecological and genetic results indicate a differentiation between C. melanoneura samples associated with the two host plants.

  18. Within-host dynamics of multi-species infections: facilitation, competition and virulence.

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    Sandeepa M Eswarappa

    Full Text Available Host individuals are often infected with more than one parasite species (parasites defined broadly, to include viruses and bacteria. Yet, research in infection biology is dominated by studies on single-parasite infections. A focus on single-parasite infections is justified if the interactions among parasites are additive, however increasing evidence points to non-additive interactions being the norm. Here we review this evidence and theoretically explore the implications of non-additive interactions between co-infecting parasites. We use classic Lotka-Volterra two-species competition equations to investigate the within-host dynamical consequences of various mixes of competition and facilitation between a pair of co-infecting species. We then consider the implications of these dynamics for the virulence (damage to host of co-infections and consequent evolution of parasite strategies of exploitation. We find that whereas one-way facilitation poses some increased virulence risk, reciprocal facilitation presents a qualitatively distinct destabilization of within-host dynamics and the greatest risk of severe disease.

  19. A novel nematode effector suppresses plant immunity by activating host reactive oxygen species-scavenging system. (United States)

    Lin, Borong; Zhuo, Kan; Chen, Shiyan; Hu, Lili; Sun, Longhua; Wang, Xiaohong; Zhang, Lian-Hui; Liao, Jinling


    Evidence is emerging that plant-parasitic nematodes can secrete effectors to interfere with the host immune response, but it remains unknown how these effectors can conquer host immune responses. Here, we depict a novel effector, MjTTL5, that could suppress plant immune response. Immunolocalization and transcriptional analyses showed that MjTTL5 is expressed specifically within the subventral gland of Meloidogyne javanica and up-regulated in the early parasitic stage of the nematode. Transgenic Arabidopsis lines expressing MjTTL5 were significantly more susceptible to M. javanica infection than wild-type plants, and vice versa, in planta silencing of MjTTL5 substantially increased plant resistance to M. javanica. Yeast two-hybrid, coimmunoprecipitation and bimolecular fluorescent complementation assays showed that MjTTL5 interacts specifically with Arabidopsis ferredoxin : thioredoxin reductase catalytic subunit (AtFTRc), a key component of host antioxidant system. The expression of AtFTRc is induced by the infection of M. javanica. Interaction between AtFTRc and MjTTL could drastically increase host reactive oxygen species-scavenging activity, and result in suppression of plant basal defenses and attenuation of host resistance to the nematode infection. Our results demonstrate that the host ferredoxin : thioredoxin system can be exploited cunningly by M. javanica, revealing a novel mechanism utilized by plant-parasitic nematodes to subjugate plant innate immunity and thereby promoting parasitism. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  20. Variation in Frankia populations of the Elaeagnus host infection group in nodules of six host plant species after inoculation with soil. (United States)

    Mirza, Babur S; Welsh, Allana; Rasul, Ghulam; Rieder, Julie P; Paschke, Mark W; Hahn, Dittmar


    The potential role of host plant species in the selection of symbiotic, nitrogen-fixing Frankia strains belonging to the Elaeagnus host infection group was assessed in bioassays with two Morella, three Elaeagnus, and one Shepherdia species as capture plants, inoculated with soil slurries made with soil collected from a mixed pine/grassland area in central Wisconsin, USA. Comparative sequence analysis of nifH gene fragments amplified from homogenates of at least 20 individual lobes of root nodules harvested from capture plants of each species confirmed the more promiscuous character of Morella cerifera and Morella pensylvanica that formed nodules with frankiae of the Alnus and the Elaeagnus host infection groups, while frankiae in nodules formed on Elaeagnus umbellata, Elaeagnus angustifolia, Elaeagnus commutata, and Shepherdia argentea generally belonged to the Elaeagnus host infection group. Diversity of frankiae of the Elaeagnus host infection groups was larger in nodules on both Morella species than in nodules formed on the other plant species. None of the plants, however, captured the entire diversity of nodule-forming frankiae. The distribution of clusters of Frankia populations and their abundance in nodules was unique for each of the plant species, with only one cluster being ubiquitous and most abundant while the remaining clusters were only present in nodules of one (six clusters) or two (two clusters) host plant species. These results demonstrate large effects of the host plant species in the selection of Frankia strains from soil for potential nodule formation and thus the significant effect of the choice of capture plant species in bioassays on diversity estimates in soil.

  1. Environment and host species shape the skin microbiome of captive neotropical bats

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    Virginie Lemieux-Labonté


    Full Text Available Background A wide range of microorganisms inhabit animal skin. This microbial community (microbiome plays an important role in host defense against pathogens and disease. Bats (Chiroptera: Mammalia are an ecologically and evolutionarily diversified group with a relatively unexplored skin microbiome. The bat skin microbiome could play a role in disease resistance, for example, to white nose syndrome (WNS, an infection which has been devastating North American bat populations. However, fundamental knowledge of the bat skin microbiome is needed before understanding its role in health and disease resistance. Captive neotropical frugivorous bats Artibeus jamaicensis and Carollia perspicillataprovide a simple controlled system in which to characterize the factors shaping the bat microbiome. Here, we aimed to determine the relative importance of habitat and host species on the bat skin microbiome. Methods We performed high-throughput 16S rRNA gene sequencing of the skin microbiome of two different bat species living in captivity in two different habitats. In the first habitat, A. jamaicensis and C. perspicillata lived together, while the second habitat contained only A. jamaicensis. Results We found that both habitat and host species shape the composition and diversity of the skin microbiome, with habitat having the strongest influence. Cohabitating A. jamaicensis and C. perspicillata shared more similar skin microbiomes than members of the same species (A. jamaicensis across two habitats. Discussion These results suggest that in captivity, the skin microbial community is homogenised by the shared environments and individual proximities of bats living together in the same habitat, at the expense of the innate host species factors. The predominant influence of habitat suggests that environmental microorganisms or pathogens might colonize bat skin. We also propose that bat populations could differ in pathogen susceptibility depending on their immediate

  2. Environment and host species shape the skin microbiome of captive neotropical bats (United States)

    Tromas, Nicolas; Shapiro, B. Jesse; Lapointe, François-Joseph


    Background A wide range of microorganisms inhabit animal skin. This microbial community (microbiome) plays an important role in host defense against pathogens and disease. Bats (Chiroptera: Mammalia) are an ecologically and evolutionarily diversified group with a relatively unexplored skin microbiome. The bat skin microbiome could play a role in disease resistance, for example, to white nose syndrome (WNS), an infection which has been devastating North American bat populations. However, fundamental knowledge of the bat skin microbiome is needed before understanding its role in health and disease resistance. Captive neotropical frugivorous bats Artibeus jamaicensis and Carollia perspicillataprovide a simple controlled system in which to characterize the factors shaping the bat microbiome. Here, we aimed to determine the relative importance of habitat and host species on the bat skin microbiome. Methods We performed high-throughput 16S rRNA gene sequencing of the skin microbiome of two different bat species living in captivity in two different habitats. In the first habitat, A. jamaicensis and C. perspicillata lived together, while the second habitat contained only A. jamaicensis. Results We found that both habitat and host species shape the composition and diversity of the skin microbiome, with habitat having the strongest influence. Cohabitating A. jamaicensis and C. perspicillata shared more similar skin microbiomes than members of the same species (A. jamaicensis) across two habitats. Discussion These results suggest that in captivity, the skin microbial community is homogenised by the shared environments and individual proximities of bats living together in the same habitat, at the expense of the innate host species factors. The predominant influence of habitat suggests that environmental microorganisms or pathogens might colonize bat skin. We also propose that bat populations could differ in pathogen susceptibility depending on their immediate environment and

  3. Structure of capsule around acanthocephalan Corynosoma strumosum from uncommon paratenic hosts-lizards of two species. (United States)

    Skorobrechova, Ekaterina M; Nikishin, Vladimir P; Lisitsyna, Olga I


    Micromorphology and ultrastructure of capsule forming around acanthocephalan Corynosoma strumosum in uncommon paratenic hosts-lizards Lacerta agilis and Lacerta viridis-have been studied. Experimental infestation of the lizards by acanthocephalans obtained from naturally infested sea fishes showed that only small amount of parasites occurred in the intestine of the host was able to migrate into body cavity and to be encapsulated. Micromorphology of capsules of different ages from different species of lizards and micromorphology and ultrastructure of capsules at the age of 1.5 and 10 days appeared to be similar. In the capsule's structure cells of inflammatory rank were prevailing: mononuclear and multinuclear macrophages, eosinophils, and basophils. Fibroblasts were not numerous and were located only in the outer part of a capsule; exocellular collagen fibers were absent. Inflammatory character of capsule confirms the idea that lizards are unsuitable paratenic hosts for corynosomes.

  4. Remote sensing of the distribution and abundance of host species for spruce budworm in Northern Minnesota and Ontario (United States)

    Peter T. Wolter; Philip A. Townsend; Brian R. Sturtevant; Clayton C. Kingdon


    Insects and disease affect large areas of forest in the U.S. and Canada. Understanding ecosystem impacts of such disturbances requires knowledge of host species distribution patterns on the landscape. In this study, we mapped the distribution and abundance of host species for the spruce budworm (Choristoneura fumiferana) to facilitate landscape scale...

  5. Survey and competition assay data suggest species-specific difference in host/niche adaptation influence the distribution of Fusarium graminearum species complex pathogens in Brazil (United States)

    The Fusarium graminearum species complex (FGSC) comprises at least 16 toxigenic species of economic concern to cereal crops. In Brazil, six species of the FGSC have been identified, but their frequencies vary according to the host species. Although F. graminearum (Fgra) is dominant in wheat (>90%) a...


    Leebens-Mack, Jim; Pellmyr, Olle; Brock, Marcus


    Host specialization is an important mechanism of diversification among phytophagous insects, especially when they are tightly associated with their hosts. The well-known obligate pollination mutualism between yucca moths and yuccas represent such an association, but the degree of host specificity and modes of specialization in moth evolution is unclear. Here we use molecular tools to test the morphology-based hypothesis that the moths pollinating two yuccas, Yucca baccata and Y. schidigera, are distinct species. Host specificity was assessed in a zone of sympatry where the hosts are known to hybridize. Because the moths are the only pollinators, the plant hybrids are evidence that the moths occasionally perform heterospecific pollination. Nucleotide variation was assessed in a portion of the mitochondrial gene COI, and in an intron within a nuclear lysozyme gene. Moths pollinating Y. baccata and Y. schidigera were inferred to be genetically isolated because there was no overlap in alleles at either locus, and all but one of the moths was found on their native host in the hybrid zone. Moreover, genetic structure was very weak across the range of each moth species: estimates of FST for the lysozyme intron were 0.043 (SE = ± 0.004) and 0.021 (SE = ± 0.006) for the baccata and schidigera pollinators, respectively; estimated FST for COI in the baccata moths was 0.228 (± 0.012), whereas schidigera pollinators were fixed for a single allele. These results reveal a high level of migration among widely separated moth populations. We predict that pollen-mediated gene flow among conspecific yuccas is considerable and hypothesize that geographic separation is a limited barrier both for yuccas and for yucca moths. © 1998 The Society for the Study of Evolution.

  7. Effect of Host Species on Topography of the Fitness Landscape for a Plant RNA Virus (United States)

    Cervera, Héctor; Lalić, Jasna


    ABSTRACT Adaptive fitness landscapes are a fundamental concept in evolutionary biology that relate the genotypes of individuals to their fitness. In the end, the evolutionary fate of evolving populations depends on the topography of the landscape, that is, the numbers of accessible mutational pathways and possible fitness peaks (i.e., adaptive solutions). For a long time, fitness landscapes were only theoretical constructions due to a lack of precise information on the mapping between genotypes and phenotypes. In recent years, however, efforts have been devoted to characterizing the properties of empirical fitness landscapes for individual proteins or for microbes adapting to artificial environments. In a previous study, we characterized the properties of the empirical fitness landscape defined by the first five mutations fixed during adaptation of tobacco etch potyvirus (TEV) to a new experimental host, Arabidopsis thaliana. Here we evaluate the topography of this landscape in the ancestral host Nicotiana tabacum. By comparing the topographies of the landscapes for the two hosts, we found that some features remained similar, such as the existence of fitness holes and the prevalence of epistasis, including cases of sign and reciprocal sign epistasis that created rugged, uncorrelated, and highly random topographies. However, we also observed significant differences in the fine-grained details between the two landscapes due to changes in the fitness and epistatic interactions of some genotypes. Our results support the idea that not only fitness tradeoffs between hosts but also topographical incongruences among fitness landscapes in alternative hosts may contribute to virus specialization. IMPORTANCE Despite its importance for understanding virus evolutionary dynamics, very little is known about the topography of virus adaptive fitness landscapes, and even less is known about the effects that different host species and environmental conditions may have on this

  8. COI and ITS2 sequences delimit species, reveal cryptic taxa and host specificity of fig-associated Sycophila (Hymenoptera, Eurytomidae). (United States)

    Li, Yanwei; Zhou, Xin; Feng, Gui; Hu, Haoyuan; Niu, Liming; Hebert, Paul D N; Huang, Dawei


    Although the genus Sycophila has broad host preferences, some species are specifically associated with figs as nonpollinator wasps. Because of their sexual dimorphism, morphological plasticity, cryptic mating behaviour and poorly known biology, species identifications are often uncertain. It is particularly difficult to match conspecific females and males. In this study, we employed two molecular markers, mitochondrial COI and nuclear ITS2, to identify Sycophila from six Chinese fig species. Morphological studies revealed 25 female and male morphs, while sequence results for both genes were consistent in supporting the presence of 15 species, of which 13 were host specialists and two used dual hosts. A single species of Sycophila was respectively found on four fig species, but six species were isolated from Ficus benjamina and a same number was reared from Ficus microcarpa. Sequence results revealed three male morphs in one species and detected two species that were overlooked by morphological analysis.

  9. New African species of Echinobothrium (Cestoda: Diphyllidea) and implications for the identities of their skate hosts. (United States)

    Caira, J N; Rodriguez, N; Pickering, M


    Two new species of diphyllidean cestodes of the genus Echinobothrium, each hosted by a different skate species in the Raja miraletus complex, are described. Echinobothrium mercedesae n. sp. is described from R. cf. miraletus 2 off Senegal. Echinobothrium yiae n. sp. is described from R. cf. miraletus 1 off South Africa. Both species are small worms that differ from their 29 described congeners in the combination of number of cephalic peduncle spines per column, hook formula, number and arrangement of testes, and arrangement of vitelline follicles. They are easily distinguished from one another in that whereas the vitelline follicles of E. yiae n. sp. are circumcortical, they are lateral in E. mercedesae n. sp., and also in number of cephalic peduncle spines per column (14-17 vs. 10-12). Echinobothrium yiae n. sp. is also unusual in that the cephalic peduncle spines stop short of the anterior margin of the peduncle. In addition, although the paucity of available material precluded their formal description, evidence of 2 additional new species parasitizing R. miraletus also from Senegal is presented. In combination these worms provide support for the interpretation that what is currently recognized as Raja miraletus actually consists of a complex of geographically restricted species, rather than a polymorphic species of multiple parapatric or allopatrically distributed populations. This interpretation is not only supported by previously published molecular data, but also by newly collected morphological data involving differences in the color patterns of disc ocelli among host specimens of the 3 forms available as a result of digital efforts to ensure the accuracy of host identifications, which are also presented here.

  10. Optimum and maximum host size at parasitism for the endoparasitoid Hyposoter didymator (Hymenoptera: Ichneumonidae) differ greatly between two host species

    NARCIS (Netherlands)

    Reudler Talsma, J.H.; Elzinga, J.A.; Harvey, J.A.; Biere, A.


    Host size is considered a reliable indicator of host quality and an important determinant of parasitoid fitness. Koinobiont parasitoids attack hosts that continue feeding and growing during parasitism. In contrast with hemolymph-feeding koinobionts, tissue-feeding koinobionts face not only a minimum

  11. Effects of host species and environment on the skin microbiome of Plethodontid salamanders. (United States)

    Muletz Wolz, Carly R; Yarwood, Stephanie A; Campbell Grant, Evan H; Fleischer, Robert C; Lips, Karen R


    The amphibian skin microbiome is recognized for its role in defence against pathogens, including the deadly fungal pathogen Batrachochytrium dendrobatidis (Bd). Yet, we have little understanding of evolutionary and ecological processes that structure these communities, especially for salamanders and closely related species. We investigated patterns in the distribution of bacterial communities on Plethodon salamander skin across host species and environments. Quantifying salamander skin microbiome structure contributes to our understanding of how host-associated bacteria are distributed across the landscape, among host species, and their putative relationship with disease. We characterized skin microbiome structure (alpha-diversity, beta-diversity and bacterial operational taxonomic unit [OTU] abundances) using 16S rRNA gene sequencing for co-occurring Plethodon salamander species (35 Plethodon cinereus, 17 Plethodon glutinosus, 10 Plethodon cylindraceus) at three localities to differentiate the effects of host species from environmental factors on the microbiome. We sampled the microbiome of P. cinereus along an elevational gradient (n = 50, 700-1,000 m a.s.l.) at one locality to determine whether elevation predicts microbiome structure. Finally, we quantified prevalence and abundance of putatively anti-Bd bacteria to determine if Bd-inhibitory bacteria are dominant microbiome members. Co-occurring salamanders had similar microbiome structure, but among sites salamanders had dissimilar microbiome structure for beta-diversity and abundance of 28 bacterial OTUs. We found that alpha-diversity increased with elevation, beta-diversity and the abundance of 17 bacterial OTUs changed with elevation (16 OTUs decreasing, 1 OTU increasing). We detected 11 putatively anti-Bd bacterial OTUs that were present on 90% of salamanders and made up an average relative abundance of 83% (SD ± 8.5) per salamander. All salamanders tested negative for Bd. We conclude that

  12. Endophytic Epichloë species and their grass hosts: from evolution to applications. (United States)

    Saikkonen, Kari; Young, Carolyn A; Helander, Marjo; Schardl, Christopher L


    The closely linked fitness of the Epichloë symbiont and the host grass is presumed to align the coevolution of the species towards specialization and mutually beneficial cooperation. Ecological observations demonstrating that Epichloë-grass symbioses can modulate grassland ecosystems via both above- and belowground ecosystem processes support this. In many cases the detected ecological importance of Epichloë species is directly or indirectly linked to defensive mutualism attributable to alkaloids of fungal-origin. Now, modern genetic and molecular techniques enable the precise studies on evolutionary origin of endophytic Epichloë species, their coevolution with host grasses and identification the genetic variation that explains phenotypic diversity in ecologically relevant characteristics of Epichloë-grass associations. Here we briefly review the most recent findings in these areas of research using the present knowledge of the genetic variation that explains the biosynthetic pathways driving the diversity of alkaloids produced by the endophyte. These findings underscore the importance of genetic interplay between the fungus and the host in shaping their coevolution and ecological role in both natural grass ecosystems, and in the agricultural arena.

  13. Song learning in brood-parasitic indigobirds Vidua chalybeata: song mimicry of the host species. (United States)

    Payne; Payne; Woods


    Brood-parasitic village indigobirds, Vidua chalybeata, were bred in captivity and foster-reared by their normal host, red-billed firefinch, Lagonosticta senegala, or by an experimental foster species, Bengalese finch, Lonchura striata. Male indigobirds reared by Bengalese finches developed the songs of Bengalese finches, and males reared by firefinches developed songs of firefinches. Males copied their foster father only when they had lived with him long after independence (45 days post-fledging), while males separated normally at independence (22-24 days post-fledging) copied songs of other individuals and not songs of their foster father. Males reared by Bengalese finches showed no preference to learn firefinch song over songs of the experimental foster species or other control finch species even when they had lived with firefinches as companions from the time of fledging to independence. Males copied several song themes, acquired the same number of mimicry songs, and acquired their songs at the same age, whether reared by Bengalese finches or by firefinches. When they lived with other indigobirds, the male indigobirds copied mimicry songs of male indigobirds that mimicked the same foster species. We predicted mimicry-song specificity and repertoire size in experimental indigobirds from a hypothesis of an early developmental period when young indigobirds focus their attention on their foster parents, and a later period when they direct their attention to other birds with similar songs. The predictions, based on field observations of wild birds, were that (1) males reared by a novel foster species other than the normal host would learn the song of that foster species, and (2) males that left their foster parents at the normal time of independence would copy the songs of other individuals, including other adult indigobirds that mimicked the same foster species. Begging calls of young indigobirds did not mimic the calls of young firefinches. Indigobirds reared alone

  14. Small Ruminant Lentiviruses (SRLVs Break the Species Barrier to Acquire New Host Range

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    Juliano Cezar Minardi da Cruz


    Full Text Available Zoonotic events of simian immunodeficiency virus (SIV from non-human primates to humans have generated the acquired immunodeficiency syndrome (AIDS, one of the most devastating infectious disease of the last century with more than 30 million people dead and about 40.3 million people currently infected worldwide. Human immunodeficiency virus (HIV-1 and HIV-2, the two major viruses that cause AIDS in humans are retroviruses of the lentivirus genus. The genus includes arthritis-encephalitis virus (CAEV and Maedi-Visna virus (MVV, and a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs, affecting goat and sheep. Lentivirus genome integrates into the host DNA, causing persistent infection associated with a remarkable diversity during viral replication. Direct evidence of mixed infections with these two closely related SRLVs was found in both sheep and goats. The evidence of a genetic continuum with caprine and ovine field isolates demonstrates the absence of an efficient species barrier preventing cross-species transmission. In dual-infected animals, persistent infections with both CAEV and MVV have been described, and viral chimeras have been detected. This not only complicates animal trade between countries but favors the risk that highly pathogenic variants may emerge as has already been observed in the past in Iceland and, more recently, in outbreaks with virulent strains in Spain. SRLVs affecting wildlife have already been identified, demonstrating the existence of emergent viruses adapted to new hosts. Viruses adapted to wildlife ruminants may acquire novel biopathological properties which may endanger not only the new host species but also domestic ruminants and humans. SRLVs infecting sheep and goats follow a genomic evolution similar to that observed in HIV or in other lentiviruses. Lentivirus genetic diversity and host factors leading to the establishment of naturally occurring virulent versus avirulent infections

  15. The Effect of Host-Plant Phylogenetic Isolation on Species Richness, Composition and Specialization of Insect Herbivores: A Comparison between Native and Exotic Hosts.

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    Julio Miguel Grandez-Rios

    Full Text Available Understanding the drivers of plant-insect interactions is still a key issue in terrestrial ecology. Here, we used 30 well-defined plant-herbivore assemblages to assess the effects of host plant phylogenetic isolation and origin (native vs. exotic on the species richness, composition and specialization of the insect herbivore fauna on co-occurring plant species. We also tested for differences in such effects between assemblages composed exclusively of exophagous and endophagous herbivores. We found a consistent negative effect of the phylogenetic isolation of host plants on the richness, similarity and specialization of their insect herbivore faunas. Notably, except for Jaccard dissimilarity, the effect of phylogenetic isolation on the insect herbivore faunas did not vary between native and exotic plants. Our findings show that the phylogenetic isolation of host plants is a key factor that influences the richness, composition and specialization of their local herbivore faunas, regardless of the host plant origin.

  16. Host selection of symbiotic cyanobacteria in 31 species of the Australian cycad genus: Macrozamia (Zamiaceae). (United States)

    Gehringer, Michelle M; Pengelly, Jasper J L; Cuddy, William S; Fieker, Claus; Forster, Paul I; Neilan, Brett A


    The nitrogen-fixing cyanobacterium Nostoc is a commonly occurring terrestrial and aquatic cyanobacterium often found in symbiosis with a wide range of plant, algal, and fungal species. We investigated the diversity of cyanobacterial species occurring within the coralloid roots of different Macrozamia cycad species at diverse locations throughout Australia. In all, 74 coralloid root samples were processed and 56 endosymbiotic cyanobacteria were cultured. DNA was isolated from unialgal cultures and a segment of the 16S rRNA gene was amplified and sequenced. Microscopic analysis was performed on representative isolates. Twenty-two cyanobacterial species were identified, comprising mostly Nostoc spp. and a Calothrix sp. No correlation was observed between a cycad species and its resident cyanobiont species. The predominant cyanobacterium isolated from 18 root samples occurred over a diverse range of environmental conditions and within 14 different Macrozamia spp. Phylogenetic analysis indicated that endosymbionts were not restricted to previously described terrestrial species. An isolate clustering with Nostoc PCC7120, an aquatic strain, was identified. This is the first comprehensive study to identify the endosymbionts within a cycad genus using samples obtained from their natural habitats. These results indicate that there is negligible host specialization of cyanobacterial endosymbionts within the cycad genus Macrozamia in the wild.

  17. Population dynamics of Scirtothrips dorsalis (Thysanoptera: Thripidae) and other thrips species on two ornamental host plant species in Southern Florida. (United States)

    Mannion, Catharine M; Derksen, Andrew I; Seal, Dakshina R; Osborne, Lance S; Martin, Cliff G


    Since its 2005 introduction into the United States, chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), has become a problematic pest of agronomic, vegetable, fruit, and ornamental plants. Knowledge of its population dynamics may help managers better monitor and control S. dorsalis. Population estimates were recorded for S. dorsalis and other thrips species on Knock-Out rose (Rosa 'Radrazz') and green buttonwood (Conocarpus erectus L.) from July 2007 to September 2008 in two field plots (one per plant species) in Homestead, FL. Yellow sticky card traps and samples of terminals, flowers, buds, and leaves were collected. S. dorsalis accounted for 95% of all thrips individuals collected from plants and 84% from traps with the remainder including at least 18 other thrips species. More thrips were caught on or flying near rose plants (47,438) than on or near buttonwoods (5,898), and on-plant densities of S. dorsalis appeared higher for rose than for buttonwood. Compared with rose leaves, rose buds, terminals, and flowers each had higher numbers of S. dorsalis, and buds and terminals had higher densities. On each host plant species, S. dorsalis density fluctuated over time with peaks in the late spring, summer, and fall, but populations were consistently low in the late winter and early spring. On roses, increased plant damage ratings correlated with reduced numbers of flowers and buds, reduced mean flower areas, and increased on-plant number and density of S. dorsalis. There were positive correlations over time between S. dorsalis density and plant damage rating for rose flowers (R = 0.78; P = 0.0003) and for buttonwood terminals (R = 0.90; P = 0.0001). Yellow sticky card traps were effective for monitoring S. dorsalis and may be especially useful and economically justified for the most susceptible hosts, but they also work well for less susceptible hosts. A good S. dorsalis scouting program should hence consider trap catches and symptoms such as leaf

  18. Comparing feeding and reproductive parameters of Amblyomma parvum tick populations (Acari: Ixodidae) from Brazil and Argentina on various host species. (United States)

    Gerardi, Monize; Martins, Maria Marlene; Nava, Santiago; Szabó, Matias Pablo Juan


    Amblyomma parvum is a Neotropical tick that is widely spread and a potential vector of pathogens, including Rickettsiae. Genetic differences are remarkable between A. parvum populations from Brazil and Argentina. In this work, feeding and reproduction parameters of A. parvum ticks from these two populations were compared on some key host species to evaluate possible differences in host suitability between them. On the whole parameters of these tick populations were similar when fed on the same host and varied similarly on different host species. Still, bovines were more suitable host for Argentinian larvae than for Brazilian cohorts. It was observed that guinea pigs were the best host A. parvum immatures from both origins, as depicted from higher recovery rate of larvae and heavier engorged nymph weights. Canids and bovids were host species most suitable to adults of both tick populations as shown by the highest number of larvae produced by adult females that engorged on these hosts. Taken together, results showed that in spite of the genetic divergence, A. parvum from Argentina and Brazil have similar biological performance on various host species.

  19. Host selection and species preference of the Red-Billed Oxpecker Buphagus Erythrorhynchus in the Kruger National Park

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    J. H Grobler


    Full Text Available The host selection and species preference of the Red- billed Oxpecker was investigated during January and February 1979, in the southern portion of the Kruger National Park, Republic of South Africa. A total of 19 species of larger mammals were looked at and of these 11 were utilised as hosts. Giraffe Giraffa camelopardalis, were found to be the most import- ant host and ranked well above the others as a preferred species. Published data on oxpeckers were reviewed with the view to possible translocation of the birds as a measure to increase their now limited distribution.

  20. Host preferences of arbuscular mycorrhizal fungi colonizing annual herbaceous plant species in semiarid Mediterranean prairies. (United States)

    Torrecillas, E; Alguacil, M M; Roldán, A


    In this study, we have analyzed and compared the diversities of the arbuscular mycorrhizal fungi (AMF) colonizing the roots of five annual herbaceous species (Hieracium vulgare, Stipa capensis, Anagallis arvensis, Carduus tenuiflorus, and Avena barbata) and a perennial herbaceous species (Brachypodium retusum). Our goal was to determine the differences in the communities of the AMF among these six plant species belonging to different families, using B. retusum as a reference. The AMF small-subunit rRNA genes (SSU) were subjected to nested PCR, cloning, sequencing, and phylogenetic analysis. Thirty-six AMF phylotypes, belonging to Glomus group A, Glomus group B, Diversispora, Paraglomus, and Ambispora, were identified. Five sequence groups identified in this study clustered to known glomalean species or isolates: group Glomus G27 to Glomus intraradices, group Glomus G19 to Glomus iranicum, group Glomus G10 to Glomus mosseae, group Glomus G1 to Glomus lamellosum/etunicatum/luteum, and group Ambispora 1 to Ambispora fennica. The six plant species studied hosted different AMF communities. A certain trend of AMF specificity was observed when grouping plant species by taxonomic families, highlighting the importance of protecting and even promoting the native annual vegetation in order to maintain the biodiversity and productivity of these extreme ecosystems.

  1. Population dynamics of two diplectanid species (Monogenea) parasitising sparid hosts (Sparidae). (United States)

    Emre, Yilmaz; Emre, Nesrin; Aydogdu, Ali; Bušelić, Ivana; Smales, Lesley R; Mladineo, Ivona


    Economically important sparid fish species, gilthead (Sparus aurata) and white seabream (Diplodus sargus) (Sparidae) are frequently parasitised by diplectanid monogeneans, known to induce severe losses in farming conditions. We have analysed population dynamic of two diplectanid species, Lamellodiscus echeneis and Lamellodiscus ignoratus (Monogenea: Diplectanidae) collected from two bream species in the Beymelek Lagoon (southwest coast of Turkey), comparing it between different host variables (fish size, age and sex) in order to have insight in parasites' ecology, important for managing parasitosis in the intensive aquaculture system. In seabream (N = 127), L. echeneis prevalence was 46.5 % (exact 95 % confidence limits 38.90-54.14), mean abundance 5.64 (bootstrap 95 % confidence limits 4.20-7.65) and mean intensity 12.14 (bootstrap 95 % confidence limits 9.49-15.59). In white seabream (N = 102), L. ignoratus prevalence was 24.5 % (exact 95 % confidence limits 16.53-34.03), mean abundance 1.73 (bootstrap 95 % confidence limits 0.98-3.21) and mean intensity 7.04 (bootstrap 95 % confidence limits 4.60-11.40). Parasites' parameters differed only between seasons in both hosts and between age categories in gilthead, but not in white seabream.

  2. Wildly Growing Asparagus (Asparagus officinalis L.) Hosts Pathogenic Fusarium Species and Accumulates Their Mycotoxins. (United States)

    Stępień, Łukasz; Waśkiewicz, Agnieszka; Urbaniak, Monika


    Asparagus officinalis L. is an important crop in many European countries, likely infected by a number of Fusarium species. Most of them produce mycotoxins in plant tissues, thus affecting the physiology of the host plant. However, there is lack of information on Fusarium communities in wild asparagus, where they would definitely have considerable environmental significance. Therefore, the main scientific aim of this study was to identify the Fusarium species and quantify their typical mycotoxins present in wild asparagus plants collected at four time points of the season. Forty-four Fusarium strains of eight species--Fusarium acuminatum, Fusarium avenaceum, Fusarium culmorum, Fusarium equiseti, Fusarium oxysporum, Fusarium proliferatum, Fusarium sporotrichioides, and Fusarium tricinctum--were isolated from nine wild asparagus plants in 2013 season. It is the first report of F. sporotrichioides isolated from this particular host. Fumonisin B1 was the most abundant mycotoxin, and the highest concentrations of fumonisins B1-B3 and beauvericin were found in the spears collected in May. Moniliformin and enniatins were quantified at lower concentrations. Mycotoxins synthesized by individual strains obtained from infected asparagus tissues were assessed using in vitro cultures on sterile rice grain. Most of the F. sporotrichioides strains synthesized HT-2 toxin and F. equiseti strains were found to be effective zearalenone producers.

  3. Diversity and Distribution of Host Animal Species of Hantavirus and Risk to Human Health in Jiuhua Mountain Area, China

    Institute of Scientific and Technical Information of China (English)

    HU Xing Qiang; LI Shi Guang; LIU Hong; WANG Jun; HUA Ri Mao


    Objective To investigate the diversity and the distribution of host animal species of hantavirus and the effect on human health in Jiuhua Mountain area, China. Methods The host animal species of hantavirus was surveyed by using the trap method and the species diversity was evaluated by using the Simpson, Shannon-Weaner, and Pielou indices. Hantavirus antigens or antibodies in lung and blood samples of all the captured host animals were detected by direct or indirect immunofluorescence. Results Nine animal species of hantavirus were distributed in the forest ecosystem of Jiuhua Mountain. Of these, Niviventer confucianus and Apodemus agrarius were predominant, and N. confucianus, Rattus norvegicus, and Mus musculus had relatively large niche breadth index values. The host animals in the eastern and western mountain regions shared similar biodiversity index characteristics, predominant species, and species structures. Hantavirus was detected in 5 host animal species in Jiuhua Mountain area, the carriage rate of hantavirus was 6.03%. The average density of host animals in forest areas of the mountainous area was only 2.20%, and the virus infection rate in the healthy population was 2.33%. Conclusion The circulation of hantavirus was low in the forest areas of Jiuhua Mountain and did not pose a threat to human health.

  4. Validation of a Model for Prediction of Host Damage by Two Nematode Species


    Duncan, Larry W.; Ferris, Howard


    Plant roots were mechanically injured or subjected to nematode parasitism to test the model of host damage by two nematode species: y = m' + (l - m')c'z₁P₁₁z₂P₁₂ for y ≤ 1.0 and y = 1.0 for y > 1.0, where m' = m₁ + (m₂ - m₁) (1 - y₂)/[(1 - y₁) + (l - y₂)] and c' = (z₁-T₁ + z₂-T₂)/2. Damage functions for greenhouse-grown radish plants (cv. Cherry Belle) mechanically injured with small or large steel needles were used to predict growth of plants injured by both needles. Growth predictions accou...

  5. West Nile virus reemergence in Romania: a serologic survey in host species. (United States)

    Ludu Oslobanu, Elena Luanda; Mihu-Pintilie, Alin; Anită, Dragos; Anita, Adriana; Lecollinet, Sylvie; Savuta, Gheorghe


    The presence of West Nile virus (WNV) in humans has been known in Romania since the 1950s; the 1996 epidemics emphasized the reemergence potential of WNV in Romania. Serological surveys made on susceptible species, known as good sentinels or reservoir hosts, e.g., horses, wild and domestic birds were undertaken from 2006-2011. Our results corroborated incidence data in human patients and other recent seroprevalence studies in animals, and should partially clarify the emergence of WNV in the eastern rural territories of Romania. It also highlighted risk zones for endemic WNV infection in Romania.

  6. Is induction ability of seed germination of Phelipanche ramosa phylogenetically structured among hosts? A case study on Fabaceae species. (United States)

    Perronne, Rémi; Gibot-Leclerc, Stéphanie; Dessaint, Fabrice; Reibel, Carole; Le Corre, Valérie


    Phelipanche ramosa is a major root-holoparasitic damaging weed characterized by a broad host range, including numerous Fabaceae species. In France, the agricultural threat posed by P. ramosa has increased over two decades due to the appearance of a genetically differentiated pathovar presenting a clear host specificity for oilseed rape. The new pathovar has led to a massive expansion of P. ramosa in oilseed rape fields. The germination rate of P. ramosa seeds is currently known to vary among P. ramosa pathovars and host species. However, only a few studies have investigated whether phylogenetic relatedness among potential host species is a predictor of the ability of these species to induce the seed germination of parasitic weeds by testing for phylogenetic signal. We focused on a set of 12 Fabaceae species and we assessed the rate of induction of seed germination by these species for two pathovars based on in vitro co-cultivation experiments. All Fabaceae species tested induced the germination of P. ramosa seeds. The germination rate of P. ramosa seeds varied between Fabaceae species and tribes studied, while pathovars appeared non-influential. Considering oilseed rape as a reference species, we also highlighted a significant phylogenetic signal. Phylogenetically related species therefore showed more similar rates of induction of seed germination than species drawn at random from a phylogenetic tree. In in vitro conditions, only Lotus corniculatus induced a significantly higher germination rate than oilseed rape, and could potentially be used as a catch crop after confirmation of these results under field conditions.

  7. Infection, specificity and host manipulation of Australapatemon sp. (Trematoda, Strigeidae) in two sympatric species of leeches (Hirudinea). (United States)

    Karvonen, Anssi; Faltýnková, Anna; Choo, Jocelyn Mah; Valtonen, E Tellervo


    Factors that drive parasite specificity and differences in infection dynamics among alternative host species are important for ecology and evolution of host-parasite interactions, but still often poorly known in natural systems. Here, we investigated spatiotemporal dynamics of infection, host susceptibility and parasite-induced changes in host phenotype in a rarely explored host-parasite system, the Australapatemon sp. trematode infecting two sympatric species of freshwater leeches, Erpobdella octoculata and Helobdella stagnalis. We show significant variation in infection abundance between the host species in both space and time. Using experimental infections, we also show that most of this variation likely comes from interspecific differences in exposure rather than susceptibility. Moreover, we demonstrate that the hiding behaviour of E. octoculata, but not that of H. stagnalis, was impaired by the infection irrespective of the parasite abundance. This may increase susceptibility of E. octoculata to predation by the final avian host. We conclude that differences in patterns of infection and in behavioural alterations among alternative sympatric host species may arise in narrow spatial scales, which emphasises the importance of local infection and transmission dynamics for parasite life cycles.

  8. Plant Killing by Mutualistic Ants Increases the Density of Host Species Seedlings in the Dry Forest of Costa Rica


    Sabrina Amador-Vargas


    Some species of plant-mutualistic ants kill the vegetation growing in the vicinities of their host plant, creating an area of bare ground (clearing). The reduced competition in the clearing may facilitate the establishment of host species sprouts (clones and seedlings), which in turn benefits the ants with additional food and shelter (“sprout-establishment hypothesis”). To test this hypothesis, the density and origin of Acacia collinsii sprouts growing inside clearings and in the vicinities o...

  9. Response of xylem-feeding leafhopper to host plant species and plant quality. (United States)

    Rossi, A M; Brodbeck, B V; Strong, D R


    Carneocephala floridana, an oligophagous leafhopper that inhabits the salt marshes along the coasts of Florida, utilizesBorrichia frutescens andSalicornia virginica (both herbs) as primary summer hosts, but uses two grasses,Distichlis spicata andSpartina alterniflora, during the winter. We tested whether the seasonal patterns of abundance and apparent host-switching byCarneocephala are related to plant quality. In laboratory experiments, nymphs ofCarneocephala reared on nonfertilized control plants of the two herbs produced adults that were similar in size to field-collected insects. OnlyCarneocephala raised at the lowest densities onSpartina andDistichlis from the highest fertilizer treatments produced adults similar in body mass to those reared on nonfertilizedBorrichia andSalicornia. ForDistichlis, superior quality (high foliar nitrogen) plants were able to mitigate the negative effect of nymphal crowding on adult body mass. However, laboratory fertilization regimes produced an extremely high foliar nitrogen content in the two herbs and the organic acid concentration in the xylem fluid ofBorrichia, the only host species suitable for xylem fluid extraction, increased 2.5- to 3-fold. Total amino acid concentration in the xylem fluid of fertilizedBorrichia decreased compared to nonfertilized plants.Carneocephala demonstrated reduced feeding efficiencies on high nitrogenBorrichia. Our results suggest thatCarneocephala prefers, and performs better on, plants with high nitrogen content up to a threshold, beyond which high nitrogen levels result in reduced leafhopper feeding rates and assimilation efficiencies.

  10. Can the same species of Platynosomum (Trematoda: Dicrocoeliidae) infect both mammalian and avian hosts? (United States)

    Pinto, H A; Mati, V L T; Melo, A L


    The importance of platynosomiasis has increased in feline veterinary practice, but aspects related to the specificity of Platynosomum spp. in definitive hosts requires further study. Although morphological traits suggest that the same species, P. illiciens, may infect both birds and mammals, the synonymies previously proposed have not been widely accepted, likely because host specificity is assumed. In addition, the name P. fastosum has frequently been used for parasites recovered from mammals. In the present study, metacercariae (n= 100/animal) of P. illiciens recovered from lizards (Hemidactylus mabouia) in Brazil were fed to Australian parakeets (Melopsittacus undulatus) and mice. Two parasites were recovered from the liver of one M. undulatus specimen during a necropsy that was performed 105 days after infection, and all mice were found to be infected with 37 ± 12 (18-48) parasites. The morphology of the P. illiciens obtained from the parakeet was similar to that of parasites obtained from mice and those described previously from naturally infected birds and mammals. Non-specificity of P. illiciens in hosts is discussed briefly, based on the parasitological and morphological results obtained during the avian experimental platynosomiasis and the epidemiology and geographical distribution of this parasite.

  11. Hippobosca longipennis - a potential intermediate host of a species of Acanthocheilonema in dogs in northern India

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    Irwin Peter J


    Full Text Available Abstract Background Hippobosca longipennis (the 'dog louse fly' is a blood sucking ectoparasite found on wild carnivores such as cheetahs and lions and domesticated and feral dogs in Africa, the Middle East and Asia, including China. Known as an intermediate host for Acanthocheilonema dracunculoides and a transport host for Cheyletiella yasguri, it has also been suggested that H. longipennis may be a vector for other pathogens, including Acanthocheilonema sp.? nov., which was recently reported to infect up to 48% of dogs in northern India where this species of fly is known to commonly infest dogs. To test this hypothesis, hippoboscid flies feeding on dogs in Ladakh in northern India were collected and subjected to microscopic dissection. Results A total of 12 infective larvae were found in 10 out of 65 flies dissected; 9 from the head, 2 from the thorax and 1 from the abdomen. The larvae averaged 2, 900 (± 60 μm in length and 34 (± 5 μm in width and possessed morphological features characteristic of the family Onchocercidae. Genetic analysis and comparison of the 18S, ITS-2, 12S and cox-1 genes confirmed the identity of the larvae as the Acanthocheilonema sp.? nov. reported in dogs in Ladakh. Conclusion This study provides evidence for a potential intermediate host-parasite relationship between H. longipennis and the canine Acanthocheilonema sp.? nov. in northern India.

  12. Species Differentiation of Chinese Mollitrichosiphum (Aphididae: Greenideinae Driven by Geographical Isolation and Host Plant Acquirement

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    Gexia Qiao


    Full Text Available The impact of both the uplift of the Qinghai-Tibetan Plateau (QTP and the separation of the Taiwan and Hainan Islands on the evolution of the fauna and flora in adjacent regions has been a topic of considerable interest. Mollitrichosiphum is a polyphagous insect group with a wide range of host plants (14 families and distributions restricted to Southeast Asia. Based on the mitochondrial Cytochrome C Oxidase Subunit I (COI and Cytochrome b (Cytb genes, the nuclear elongation factor-1α (EF-1α gene, and the detailed distribution and host plant data, we investigated the species differentiation modes of the Chinese Mollitrichosiphum species. Phylogenetic analyses supported the monophyly of Mollitrichosiphum. The divergence time of Mollitrichosiphum tenuicorpus (c. 11.0 mya (million years ago, Mollitrichosiphum nandii and Mollitrichosiphum montanum (c. 10.6 mya was within the time frame of the uplift of the QTP. Additionally, basal species mainly fed on Fagaceae, while species that fed on multiple plants diverged considerably later. Ancestral state reconstruction suggests that Fagaceae may be the first acquired host, and the acquisition of new hosts and the expansion of host range may have promoted species differentiation within this genus. Overall, it can be concluded that geographical isolation and the expansion of the host plant range may be the main factors driving species differentiation of Mollitrichosiphum.

  13. Variation of parasitism patterns in bats during hibernation: the effect of host species, resources, health status, and hibernation period. (United States)

    Postawa, Tomasz; Nagy, Zoltan


    During critical periods of food shortage or variable climatic conditions, the choice of an appropriate host can increase the survival and reproductive performance of parasites. In turn, one of the unique adaptations to periodical food shortages is hibernation, which is often found among insectivorous bat species in the temperate zone. While hibernating, bats are completely defenseless against both predators and ectoparasites, their immune and endocrine systems are diminished, and survival is dependent on the accumulated fat reserves. Differences in the health status or in the rate of consumption of the resources might also explain species-specific differences in ectoparasite abundance, especially between closely related host species, such as the greater mouse-eared bat (Myotis myotis) and the lesser mouse-eared bat (M. blythii) during hibernation. In the present study, the abundance of two ecologically distinct (summer and winter) types of ectoparasites was examined in terms of its influence on the body condition and hemoglobin content of the two host species. The effects of demographic factors, such as host sex and age, were also investigated. Despite a similar pattern of deteriorating body condition and hemoglobin concentration, M. myotis was more parasitized than was M. blythii. The marked decrease in hemoglobin content in first-year females of both host species correlated with the highest parasite load and indicated a risk of anemia. At the intraspecific level, ectoparasite abundance was not correlated with body condition (resources), but it negatively affected hemoglobin content; however, this mostly concerned M. blythii, which had a lower parasite load. Therefore, it can be concluded that interspecific differences in ectoparasite abundance may result from parasites selecting the host species that is less sensitive to their activity. In turn, in summer ectoparasites, the preference for female hosts is probably attributable to the likelihood of reinfection

  14. New Raffaelea species (Ophiostomatales) from the USA and Taiwan associated with ambrosia beetles and plant hosts. (United States)

    Simmons, D Rabern; de Beer, Z Wilhelm; Huang, Yin-Tse; Bateman, Craig; Campbell, Alina S; Dreaden, Tyler J; Li, You; Ploetz, Randy C; Black, Adam; Li, Hou-Feng; Chen, Chi-Yu; Wingfield, Michael J; Hulcr, Jiri


    Raffaelea (Ophiostomatales) is a genus of more than 20 ophiostomatoid fungi commonly occurring in symbioses with wood-boring ambrosia beetles. We examined ambrosia beetles and plant hosts in the USA and Taiwan for the presence of these mycosymbionts and found 22 isolates representing known and undescribed lineages in Raffaelea. From 28S rDNA and β-tubulin sequences, we generated a molecular phylogeny of Ophiostomatales and observed morphological features of seven cultures representing undescribed lineages in Raffaelea s. lat. From these analyses, we describe five new species in Raffaelea s. lat.: R. aguacate, R. campbellii, R. crossotarsa, R. cyclorhipidia, and R. xyleborina spp. nov. Our analyses also identified two plant-pathogenic species of Raffaelea associated with previously undocumented beetle hosts: (1) R. quercivora, the causative agent of Japanese oak wilt, from Cyclorhipidion ohnoi and Crossotarsus emancipatus in Taiwan, and (2) R. lauricola, the pathogen responsible for laurel wilt, from Ambrosiodmus lecontei in Florida. The results of this study show that Raffaelea and associated ophiostomatoid fungi have been poorly sampled and that future investigations on ambrosia beetle mycosymbionts should reveal a substantially increased diversity.

  15. Determining Intermediate Hosts for Opecoelidae and Microphallidae Species (Platyhelminthes: Trematoda) in the Southeastern Pacific Coast, Using Molecular Markers. (United States)

    Leiva, Natalia Verónica; López, Zambra; González, María Teresa; Muñoz, Gabriela


    Metacercarial stages of digeneans were collected from decapod crustaceans inhabiting intertidal rocky zones in central Chile. The digeneans were identified through a molecular analysis based on the V4 region of the 18S ribosomal RNA gene. We analyzed 356 crustaceans belonging to 10 species, 115 intertidal fish belonging to 6 species, and 4 specimens of 1 coastal bird species. In total, 74.1% of crustaceans were parasitized with metacercariae. We found 1 species of Opecoelidae. This species showed low genetic divergence (0% and 0.1%) with adult digeneans found in intertidal fish and with the species Helicometrina labrisomi infesting a subtidal fish from northern Chile (Labrisomus philippii). Additionally, we found 2 species of Microphallidae, 1 closely related to Maritrema (1.3% genetic distance) and the other related to Microphallus (5% genetic distance). Therefore, our findings showed that the decapod crustaceans are relevant hosts in food webs from the southeastern Pacific coast. Furthermore, we found 5 species of crustaceans as second intermediate hosts for H. labrisomi and 2 species as secondary intermediate hosts for 2 Microphallidae, which contribute to elucidate parts of their life cycles through molecular markers and extended the host distribution of H. labrisomi in the southeastern Pacific coast.

  16. Investigating differences across host species and scales to explain the distribution of the amphibian pathogen Batrachochytrium dendrobatidis.

    Directory of Open Access Journals (Sweden)

    Anna C Peterson

    Full Text Available Many pathogens infect more than one host species, and clarifying how these different hosts contribute to pathogen dynamics can facilitate the management of pathogens and can lend insight into the functioning of pathogens in ecosystems. In this study, we investigated a suite of native and non-native amphibian hosts of the pathogen Batrachochytrium dendrobatidis (Bd across multiple scales to identify potential mechanisms that may drive infection patterns in the Colorado study system. Specifically, we aimed to determine if: 1 amphibian populations vary in Bd infection across the landscape, 2 amphibian community composition predicts infection (e.g., does the presence or abundance of any particular species influence infection in others?, 3 amphibian species vary in their ability to produce infectious zoospores in a laboratory infection, 4 heterogeneity in host ability observed in the laboratory scales to predict patterns of Bd prevalence in the landscape. We found that non-native North American bullfrogs (Lithobates catesbeianus are widespread and have the highest prevalence of Bd infection relative to the other native species in the landscape. Additionally, infection in some native species appears to be related to the density of sympatric L. catesbeianus populations. At the smaller host scale, we found that L. catesbeianus produces more of the infective zoospore stage relative to some native species, but that this zoospore output does not scale to predict infection in sympatric wild populations of native species. Rather, landscape level infection relates most strongly to density of hosts at a wetland as well as abiotic factors. While non-native L. catesbeianus have high levels of Bd infection in the Colorado Front Range system, we also identified Bd infection in a number of native amphibian populations allopatric with L. catesbeianus, suggesting that multiple host species are important contributors to the dynamics of the Bd pathogen in this

  17. The metacercariae of sibling species of Meiogymnophallus, including M. rebecqui comb. nov. (Digenea: Gymnophallidae), and their effects on closely related Cerastoderma host species (Mollusca: bivalvia). (United States)

    Bowers, E A; Bartoli, P; Russell-Pinto, F; James, B L


    The morphology and ecology are described for four sibling species of digenean metacercariae: Meiogymnophallus minutus (Cobbold 1859), M. strigatus (Lebour 1908) from the estuarine cockle Cerastoderma edule L. and M. fossarum (Bartoli, 1965) and M. rebecqui (Bartoli, 1983) comb. nov. from the brackish water lagoon cockle C. glaucum (Poiret). Although occupying different sites within the two species of cockle, both M. minutus and M. fossarum infections result in pathological effects that may cause heavy host mortality. Remarkably, they also result in an inversion of the cockles in situ in the sand such that predation by the final host species is enhanced.

  18. Special plant species determines diet breadth of phytophagous insects: a study on host plant expansion of the host-specialized Aphis gossypii Glover.

    Directory of Open Access Journals (Sweden)

    Wei Wu

    Full Text Available Host specialization is a ubiquitous character of phytophagous insects. The polyphagous population is usually composed of some subpopulations that can use only a few closely related plants. Cotton-melon aphids, Aphis gossypii Glover exhibited strong host specialization, and the cotton- and cucurbits-specialized biotypes had been clearly identified. However, the experimental work that addressed the roles of plant species in determining diet breadth of phytophagous insects is rare. In the present study, we took the artificial host transfer method to assess the role of two special plants, zucchini Cucurbita zucchini L. and cowpea Vigna unguiculata (Linn. Walp, in regulating diet breadth of cotton- and cucurbits-specialized A. gossypii collected from cotton and cucumber fields and reared separately on the native host plant for ten years. The results showed that the cotton-specialized aphids did not directly use cucumber whereas the cucurbits-specialized did not use cotton regardless of the coexistence or separation of cotton and cucumber plants. Neither of the cotton- and cucurbits-specialized aphids could use capsicum Capsicum annuum, eggplant Solanum melongena, tomato Solanum lycopersicum, maize Zea mays, and radish Raphanus sativus, however, both of them could use zucchini and cowpea. Moreover, the feeding experience on zucchini led the cotton-specialized aphids to use cucumber well and finally to be transformed into the cucurbits-specialized biotype. The short-term feeding experience on cowpea resulted in the diet breadth expansion of the cucurbits-specialized aphids to use cotton. On the other hand, the diet breadth expansion of the cucurbits- and cotton-specialized aphids was only realized by different species of plant. It concluded that the special host plant did induce the conversion of feeding habits in the cotton- and cucurbits-specialized aphids, and

  19. Effect of host diversity and species assemblage composition on bovine tuberculosis (bTB) risk in Ethiopian cattle

    NARCIS (Netherlands)

    Dejene, Sintayehu; Heitkonig, Ignas; Prins, Herbert; Tessema, Zewdu K.; Boer, de Fred


    Current theories on diversity–disease relationships describe host species diversity and species identity as important factors influencing disease risk, either diluting or amplifying disease prevalence in a community. Whereas the simple term ‘diversity’ embodies a set of animal community

  20. Role of dung beetle feeding mechanisms in limiting the suitability of species as hosts for the nematode Spirocerca lupi

    DEFF Research Database (Denmark)

    du Toit, C. A.; Holter, P.; Lutermann, H.


    Various species of dung beetle serve as intermediate hosts after ingesting the embryonated eggs (1115 x 3037 mu m) of Spirocerca lupi (Spirurida: Spirocercidae) in dog faeces. The feeding mechanisms of coprophagous dung beetles restrict the size of the food particles they can ingest and hence may...... determine which species can be efficient vectors for S. lupi. In this study, we aimed to exclude certain dung beetle species as possible hosts of S. lupi based on whether or not they ingested latex beads of known diameters mixed into fresh cattle dung. We found that the majority (11/14) of species tested...... can potentially serve as intermediate hosts of S. lupi because their mouthparts allow the passage of food particles larger than the minimum size range of the eggs of this parasite....

  1. Species-Specific Adaptations of Trypanosome Morphology and Motility to the Mammalian Host.

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    Joel L Bargul


    Full Text Available African trypanosomes thrive in the bloodstream and tissue spaces of a wide range of mammalian hosts. Infections of cattle cause an enormous socio-economic burden in sub-Saharan Africa. A hallmark of the trypanosome lifestyle is the flagellate's incessant motion. This work details the cell motility behavior of the four livestock-parasites Trypanosoma vivax, T. brucei, T. evansi and T. congolense. The trypanosomes feature distinct swimming patterns, speeds and flagellar wave frequencies, although the basic mechanism of flagellar propulsion is conserved, as is shown by extended single flagellar beat analyses. Three-dimensional analyses of the trypanosomes expose a high degree of dynamic pleomorphism, typified by the 'cellular waveform'. This is a product of the flagellar oscillation, the chirality of the flagellum attachment and the stiffness of the trypanosome cell body. The waveforms are characteristic for each trypanosome species and are influenced by changes of the microenvironment, such as differences in viscosity and the presence of confining obstacles. The distinct cellular waveforms may be reflective of the actual anatomical niches the parasites populate within their mammalian host. T. vivax displays waveforms optimally aligned to the topology of the bloodstream, while the two subspecies T. brucei and T. evansi feature distinct cellular waveforms, both additionally adapted to motion in more confined environments such as tissue spaces. T. congolense reveals a small and stiff waveform, which makes these parasites weak swimmers and destined for cell adherence in low flow areas of the circulation. Thus, our experiments show that the differential dissemination and annidation of trypanosomes in their mammalian hosts may depend on the distinct swimming capabilities of the parasites.

  2. Role of multiple hosts in the cross-species transmission and emergence of a pandemic parvovirus. (United States)

    Allison, Andrew B; Harbison, Carole E; Pagan, Israel; Stucker, Karla M; Kaelber, Jason T; Brown, Justin D; Ruder, Mark G; Keel, M Kevin; Dubovi, Edward J; Holmes, Edward C; Parrish, Colin R


    Understanding the mechanisms of cross-species virus transmission is critical to anticipating emerging infectious diseases. Canine parvovirus type 2 (CPV-2) emerged as a variant of a feline parvovirus when it acquired mutations that allowed binding to the canine transferrin receptor type 1 (TfR). However, CPV-2 was soon replaced by a variant virus (CPV-2a) that differed in antigenicity and receptor binding. Here we show that the emergence of CPV involved an additional host range variant virus that has circulated undetected in raccoons for at least 24 years, with transfers to and from dogs. Raccoon virus capsids showed little binding to the canine TfR, showed little infection of canine cells, and had altered antigenic structures. Remarkably, in capsid protein (VP2) phylogenies, most raccoon viruses fell as evolutionary intermediates between the CPV-2 and CPV-2a strains, suggesting that passage through raccoons assisted in the evolution of CPV-2a. This highlights the potential role of alternative hosts in viral emergence.

  3. A fungal endophyte reinforces population adaptive differentiation in its host grass species. (United States)

    Gibert, Anaïs; Volaire, Florence; Barre, Philippe; Hazard, Laurent


    Hereditary symbioses between fungal endophytes and grasses are relatively recent in the history of plant life. Given endophyte Neotyphodium lolii in the adaptive differentiation of its host species Lolium perenne. Endophyte frequency in 22 natural L. perenne populations was established across a water availability gradient. Adaptive differentiation among five populations, and between symbiotic (S) and nonsymbiotic (NS) plants, was examined in a glasshouse experiment under nonlimiting and limiting water conditions. Genetic differentiation was subsequently assessed among populations, and between S and NS individuals, using 14 simple sequence repeats (SSR). Symbiosis frequencies were positively correlated to water availability. Adaptive population differentiation occurred following a trade-off between biomass production under nonlimiting water conditions and survivorship under water stress. Endophytic symbiosis increased plant survival in xeric populations, and reinforced competitiveness in mesic populations. No genetic difference was detected between S and NS plants within populations. Therefore, we conclude that the endophyte relationship is responsible for these effects. Local adaptation of the host plant, appears to be supported by the fungal endophyte.

  4. Exploitation of reactive oxygen species by fungi: roles in host-fungus interaction and fungal development. (United States)

    Kim, Hyo Jin


    In the past, reactive oxygen species (ROS) have been considered a harmful byproduct of aerobic metabolism. However, accumulating evidence implicates redox homeostasis, which maintains appropriate ROS levels, in cell proliferation and differentiation in plants and animals. Similarly, ROS generation and signaling are instrumental in fungal development and host-fungus interaction. In fungi, NADPH oxidase, a homolog of human gp91(phox), generates superoxide and is the main source of ROS. The mechanism of activation and signaling by NADPH oxidases in fungi appears to be largely comparable to those in plants and animals. Recent studies have shown that the fungal NADPH oxidase homologs NoxA (Nox1), NoxB (Nox2), and NoxC (Nox3) have distinct functions. In particular, these studies have consistently demonstrated the impact of NoxA on the development of fungal multicellular structures. Both NoxA and NoxB (but not NoxC) are involved in host-fungus interactions, with the function of NoxA being more critical than that of NoxB.

  5. New species and host plants of Anastrepha (Diptera: Tephritidae) primarily from Peru and Bolivia. (United States)

    Norrbom, Allen L; Rodriguez, Erick J; Steck, Gary J; Sutton, Bruce A; Nolazco, Norma


    Twenty-eight new species of Anastrepha are described and illustrated: A. acca (Bolivia, Peru), A. adami (Peru), A. amplidentata (Bolivia, Peru), A. annonae (Peru), A. breviapex (Peru), A. caballeroi (Peru), A. camba (Bolivia, Peru), A. cicra (Bolivia, Peru), A. disjuncta (Peru), A. durantae (Peru), A. echaratiensis (Peru), A. eminens (Peru), A. ericki (Peru), A. gonzalezi (Bolivia, Peru), A. guevarai (Peru), A. gusi (Peru), A. kimi (Colombia, Peru), A. korytkowskii (Bolivia, Peru), A. latilanceola (Bolivia, Peru), A. melanoptera (Peru), A. mollyae (Bolivia, Peru), A. perezi (Peru), A. psidivora (Peru), A. robynae (Peru), A. rondoniensis (Brazil, Peru), A. tunariensis (Bolivia, Peru), A. villosa (Bolivia), and A. zacharyi (Peru). The following host plant records are reported: A. amplidentata from Spondias mombin L. (Anacardiaceae); A. caballeroi from Quararibea malacocalyx A. Robyns & S. Nilsson (Malvaceae); A. annonae from Annona mucosa Jacq. and Annona sp. (Annonaceae); A. durantae from Duranta peruviana Moldenke (Verbenaceae); and A. psidivora from Psidium guajava L. (Myrtaceae).

  6. The use of silica aerogels as host matrices for chemical species

    Energy Technology Data Exchange (ETDEWEB)

    Woignier, T.; Primera, J.; Lamy, M.; Sempere, R.; Phalippou, J. [Laboratoire des Verres, Universite Montpellier II, Place Eugene Bataillon, 34095 Montpellier cedex 5 (France); Fehr, C.; Anglaret, E. [Institut de Recherche et de Developpement, PRAM quartier petit morne, BP 214 97285 le Lamentin cedex 2, Martinique (France)


    Different sets of silica aerogels (classical aerogels, partially densified aerogels, and composite aerogels) have been studied for their prospective use as host matrices for chemical species. Two relevant parameters, the mechanical properties and permeability, are measured and compared in order to discuss the advantages and drawbacks of the three different synthetic approaches. Mechanical resistance is measured by the static bending technique and permeability by an impregnation method. By adjusting the mechanical resistance and especially the mean pore-size, it is possible to control impregnation of liquid within the porous network of the aerogel. Facile liquid impregnation into mechanically durable aerogels allows one to synthesize different composites and multi-phase materials after soaking, drying and sintering. Three examples of applications are detailed: doped glass for the Faraday effect, glass-ceramics for nuclear waste containment, and liquid crystals in confined media.

  7. MAVS-dependent host species range and pathogenicity of human hepatitis A virus. (United States)

    Hirai-Yuki, Asuka; Hensley, Lucinda; McGivern, David R; González-López, Olga; Das, Anshuman; Feng, Hui; Sun, Lu; Wilson, Justin E; Hu, Fengyu; Feng, Zongdi; Lovell, William; Misumi, Ichiro; Ting, Jenny P-Y; Montgomery, Stephanie; Cullen, John; Whitmire, Jason K; Lemon, Stanley M


    Hepatotropic viruses are important causes of human disease, but the intrahepatic immune response to hepatitis viruses is poorly understood because of a lack of tractable small- animal models. We describe a murine model of hepatitis A virus (HAV) infection that recapitulates critical features of type A hepatitis in humans. We demonstrate that the capacity of HAV to evade MAVS-mediated type I interferon responses defines its host species range. HAV-induced liver injury was associated with interferon-independent intrinsic hepatocellular apoptosis and hepatic inflammation that unexpectedly resulted from MAVS and IRF3/7 signaling. This murine model thus reveals a previously undefined link between innate immune responses to virus infection and acute liver injury, providing a new paradigm for viral pathogenesis in the liver. Copyright © 2016, American Association for the Advancement of Science.

  8. Host-specific parvovirus evolution in nature is recapitulated by in vitro adaptation to different carnivore species.

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    Andrew B Allison


    Full Text Available Canine parvovirus (CPV emerged as a new pandemic pathogen of dogs in the 1970s and is closely related to feline panleukopenia virus (FPV, a parvovirus of cats and related carnivores. Although both viruses have wide host ranges, analysis of viral sequences recovered from different wild carnivore species, as shown here, demonstrated that>95% were derived from CPV-like viruses, suggesting that CPV is dominant in sylvatic cycles. Many viral sequences showed host-specific mutations in their capsid proteins, which were often close to sites known to control binding to the transferrin receptor (TfR, the host receptor for these carnivore parvoviruses, and which exhibited frequent parallel evolution. To further examine the process of host adaptation, we passaged parvoviruses with alternative backgrounds in cells from different carnivore hosts. Specific mutations were selected in several viruses and these differed depending on both the background of the virus and the host cells in which they were passaged. Strikingly, these in vitro mutations recapitulated many specific changes seen in viruses from natural populations, strongly suggesting they are host adaptive, and which were shown to result in fitness advantages over their parental virus. Comparison of the sequences of the transferrin receptors of the different carnivore species demonstrated that many mutations occurred in and around the apical domain where the virus binds, indicating that viral variants were likely selected through their fit to receptor structures. Some of the viruses accumulated high levels of variation upon passage in alternative hosts, while others could infect multiple different hosts with no or only a few additional mutations. Overall, these studies demonstrate that the evolutionary history of a virus, including how long it has been circulating and in which hosts, as well as its phylogenetic background, has a profound effect on determining viral host range.

  9. A comparative analysis of genetic differentiation across six shared willow host species in leaf- and bud-galling sawflies.

    Directory of Open Access Journals (Sweden)

    Sanna A Leppänen

    Full Text Available Genetic divergence and speciation in plant-feeding insects could be driven by contrasting selection pressures imposed by different plant species and taxa. While numerous examples of host-associated differentiation (HAD have been found, the overall importance of HAD in insect diversification remains unclear, as few studies have investigated its frequency in relation to all speciation events. One promising way to infer the prevalence and repeatability of HAD is to estimate genetic differentiation in multiple insect taxa that use the same set of hosts. To this end, we measured and compared variation in mitochondrial COI and nuclear ITS2 sequences in population samples of leaf-galling Pontania and bud-galling Euura sawflies (Hymenoptera: Tenthredinidae collected from six Salix species in two replicate locations in northern Fennoscandia. We found evidence of frequent HAD in both species complexes, as individuals from the same willow species tended to cluster together on both mitochondrial and nuclear phylogenetic trees. Although few fixed differences among the putative species were found, hierarchical AMOVAs showed that most of the genetic variation in the samples was explained by host species rather than by sampling location. Nevertheless, the levels of HAD measured across specific pairs of host species were not correlated in the two focal galler groups. Hence, our results support the hypothesis of HAD as a central force in herbivore speciation, but also indicate that evolutionary trajectories are only weakly repeatable even in temporally overlapping radiations of related insect taxa.

  10. Dispersal limitation of Tillandsia species correlates with rain and host structure in a central Mexican tropical dry forest (United States)


    Seed dispersal permits the colonization of favorable habitats and generation of new populations, facilitating escape from habitats that are in decline. There is little experimental evidence of the factors that limit epiphyte dispersion towards their hosts. In a tropical dry forest in central Mexico, we monitored the phenology of dispersion of epiphyte species of the genus Tillandsia; we tested experimentally whether precipitation could cause failures in seed dispersal and whether seed capture differs among vertical strata and between host species with high (Bursera copallifera) and low (Conzattia multiflora) epiphyte loads. With the exception of one species that presents late dispersion and low abundance, all of the species disperse prior to the onset of the rainy season. However, early rains immobilize the seeds, affecting up to 24% of the fruits in species with late dispersion. We observed that Tillandsia seeds reach both Bursera and Conzattia hosts, but found that adherence to the host is 4–5 times higher in Bursera. Furthermore, seeds liberated from Bursera travel shorter distances and up to half may remain within the same crown, while the highest seed capture takes place in the upper strata of the trees. We conclude that dispersion of Tillandsia seeds is limited by early rains and by the capture of seeds within the trees where populations concentrate. This pattern of capture also helps to explain the high concentrations of epiphytes in certain hosts, while trees with few epiphytes can be simultaneously considered deficient receivers and efficient exporters of seeds. PMID:28158320

  11. Dispersal limitation of Tillandsia species correlates with rain and host structure in a central Mexican tropical dry forest. (United States)

    Victoriano-Romero, Elizabeth; Valencia-Díaz, Susana; Toledo-Hernández, Víctor Hugo; Flores-Palacios, Alejandro


    Seed dispersal permits the colonization of favorable habitats and generation of new populations, facilitating escape from habitats that are in decline. There is little experimental evidence of the factors that limit epiphyte dispersion towards their hosts. In a tropical dry forest in central Mexico, we monitored the phenology of dispersion of epiphyte species of the genus Tillandsia; we tested experimentally whether precipitation could cause failures in seed dispersal and whether seed capture differs among vertical strata and between host species with high (Bursera copallifera) and low (Conzattia multiflora) epiphyte loads. With the exception of one species that presents late dispersion and low abundance, all of the species disperse prior to the onset of the rainy season. However, early rains immobilize the seeds, affecting up to 24% of the fruits in species with late dispersion. We observed that Tillandsia seeds reach both Bursera and Conzattia hosts, but found that adherence to the host is 4-5 times higher in Bursera. Furthermore, seeds liberated from Bursera travel shorter distances and up to half may remain within the same crown, while the highest seed capture takes place in the upper strata of the trees. We conclude that dispersion of Tillandsia seeds is limited by early rains and by the capture of seeds within the trees where populations concentrate. This pattern of capture also helps to explain the high concentrations of epiphytes in certain hosts, while trees with few epiphytes can be simultaneously considered deficient receivers and efficient exporters of seeds.

  12. Wild cervids are host for tick vectors of babesia species with zoonotic capability in Belgium. (United States)

    Lempereur, Laetitia; Wirtgen, Marc; Nahayo, Adrien; Caron, Yannick; Shiels, Brian; Saegerman, Claude; Losson, Bertrand; Linden, Annick


    Babesiosis is a tick-borne disease caused by different species of intraerythrocytic protozoan parasites within the genus Babesia. Different species of Babesia are described as potentially zoonotic and cause a malaria-like disease mainly in immunocompromised humans. Interest in the zoonotic potential of Babesia is growing and babesiosis has been described by some authors as an emergent zoonotic disease. The role of cervids to maintain tick populations and act as a reservoir host for some Babesia spp. with zoonotic capability is suspected. To investigate the range and infection rate of Babesia species, ticks were collected from wild cervids in southern Belgium during 2008. DNA extraction was performed for individual ticks, and each sample was evaluated for the absence of PCR inhibition using a PCR test. A Babesia spp. genus-specific PCR based on the 18S rRNA gene was applied to validated tick DNA extracts. A total of 1044 Ixodes ricinus ticks were collected and 1023 validated samples were subsequently screened for the presence of Babesia spp. DNA. Twenty-eight tick samples were found to be positive and identified after sequencing as containing DNA representing: Babesia divergens (3), B. divergens-like (5), Babesia sp. EU1 (11), Babesia sp. EU1-like (3), B. capreoli (2), or unknown Babesia sp. (4). This study confirms the presence of potentially zoonotic species and Babesia capreoli in Belgium, with a tick infection rate of 2.7% (95% CI 1.8,3.9%). Knowledge of the most common reservoir source for transmission of zoonotic Babesia spp. will be useful for models assessing the risk potential of this infection to humans.

  13. Plant-associated odor perception and processing in two parasitoid species with different degrees of host specificity: Implications for host location strategies. (United States)

    Das, Prithwiraj; Morawo, Tolulope; Fadamiro, Henry


    Microplitis croceipes and Cotesia marginiventris (Hymenoptera: Braconidae) are parasitoids of lepidopteran larvae with different degrees of host specificity. Both parasitoid species rely on host-related plant volatiles as odor cues to locate their herbivore hosts. To better understand mechanisms of odor processing in parasitoids, we tested responses of olfactory sensory neurons (OSNs) in the antennal sensilla placodea of female parasitoids to select plant volatiles and mixtures. The compounds tested include two green leaf volatiles (i.e., cis-3-hexenol and hexanal) and three herbivore-induced plant volatiles (i.e., cis-3-hexenyl butyrate, cis-3-hexenyl acetate and linalool). Single-sensillum recording showed that the test compounds elicited activity in large and small amplitude neurons housed in the short sensilla placodea of both parasitoid species. In general, C. marginiventris showed greater OSN responses to a low dose while M. croceipes showed greater responses to a high dose of test compounds. Binary mixtures of cis-3-hexenol and linalool inhibited OSN activity in M. croceipes, but not in C. marginiventris. These differences may have implications for odor discrimination in the two parasitoid species. In addition, anterograde neurobiotin stainings were performed to map glomerular projections of OSNs in the antennal lobe of the parasitoids. In M. croceipes, a mixture of cis-3-hexenol and linalool inhibited activity of the glomerulus activated by cis-3-hexenol alone. In C. marginiventris, a mixture of cis-3-hexenol and cis-3-hexenyl acetate showed intense labeling in their respective glomeruli, possibly suggesting a synergistic interaction. These differences in detection and coding of single compounds and mixtures may impact host location strategies in the two parasitoid species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Contrasting Plasticity in Ovariole Number Induced by A Dietary Effect of the Host Plants between Cactophilic Drosophila Species

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    Daniela Peluso


    Full Text Available Under the preference-performance hypothesis, natural selection will favor females that choose oviposition sites that optimize the fitness of their offspring. Such a preference-performance relationship may entail important consequences mainly on fitness-related traits. We used the well-characterized cactus-Drosophila system to investigate the reproductive capacity in the pair of sibling species D. buzzatii and D. koepferae reared in two alternative host plants. According to our hypothesis, ovariole number (as a proxy of reproductive capacity depends on host plant selection. Our results indicate that the capacity of D. buzzatii showed to be mild, only increasing the number of ovarioles by as much as 10% when reared in its preferred host. In contrast, D. koepferae exhibited a similar reproductive capacity across host cacti, even though it showed a preference for its primary host cactus. Our study also revealed that D. buzzatii has a larger genetic variation for phenotypic plasticity than its sibling, although ovariole number did not show clear-cut differences between species. We will discuss the weak preference-performance pattern observed in these cactophilic species in the light of nutritional and toxicological differences found between the natural host plants.

  15. Specialization and local adaptation of a fungal parasite on two host plant species as revealed by two fitness traits. (United States)

    Sicard, Delphine; Pennings, Pleuni S; Grandclément, Catherine; Acosta, Jorge; Kaltz, Oliver; Shykoff, Jacqui A


    We investigate the geographic pattern of adaptation of a fungal parasite, Colletotrichum lindemuthianum, on two host species, Phaseolus vulgaris and P. coccineus for two parasite fitness traits: infectivity (ability to attack a host individual) and aggressivity (degree of sporulation and leaf surface damage). Using a cross-inoculation experiment, we show specialization of the fungus on its host species of origin for both traits even when fungi, which originated from hosts growing in sympatry, were tested on sympatric host populations. Within the two host species, we compared infectivity and aggressivity on local versus allopatric plant-fungus combinations. We found evidence for local adaptation for the two traits on P. vulgaris but not on P. coccineus. There was no significant correlation between the degrees of local adaptation for infectivity and aggressivity, indicating that the genetic basis and the effect of selection may differ between these two traits. For the two fitness traits, a positive correlation between the degree of specialization and the degree of local adaptation was found, suggesting that specialization can be reinforced by local adaptation.

  16. Additions to the Encyrtidae and Mymaridae (Chalcidoidea) of India with new distribution and host records for some species (United States)

    Rameshkumar, A.; V, Naveen


    Abstract Background Encyrtidae and Mymaridae of India have not been surveyed in depth and hosts are not known for most of the species as the methods of collections used are passive and do not yield firsthand information on the hosts. Based on our ongoing surveys on the Encyrtidae and Mymaridae of India, we report here new distribution and host records for some species. New information Acmopolynema campylurum Xu and Lin, Litus cynipseus Haliday, Omyomymar glabrum Lin and Chiappini and Platystethynium Ogloblin (Mymaridae), and Rhytidothorax purpureiscutellum (Girault) (Encyrtidae) are reported for the first time from India. Anagyrus aquilonaris (Noyes and Hayat) is recorded as new to Arunachal Pradesh and Meghalaya. Paraphaenodiscus indicus Singh and Agarwal and Paraphaenodiscus monawari Bhuiya are recorded from south India for the first time, the latter on a new host, Pulvinaria polygonata. Chorizococcus sorghi Williams (Pseudococcidae) is reported as a host for Cryptanusia ajmerensis (Fatma & Shafee), for which no hosts are hitherto known and the male of Cryptanusia is documented for the first time. Aclerda sp. is recorded as a new host for Neastymachus axillaris Singh, Agarwal and Basha. PMID:26069438

  17. New Meliolaceae from the Brazilian Atlantic forest 2: species on host families Annonaceae, Cecropiaceae, Meliaceae, Piperaceae, Rubiaceae, Rutaceae and Tiliaceae. (United States)

    Pinho, Danilo Batista; Firmino, André Luiz; Ferreira-Junior, Walnir Gomes; Pereira, Olinto Liparini


    Continuing the study of black mildews in fragments of the Atlantic forest, three new species and five new records are described herein. Irenopsis luheae-grandiflorae, Meliola vicosensis and Meliola xylopia-sericiae are new species. Cecropia hololeuca, Piper gaudichaudianum and Trichilia lepidota are new hosts for Asteridiella leucosykeae, Asteridiella glabroides and Meliola trichiliae respectively. Asteridiella obesa and Meliola psychotriae var. chiococcae are reported for the first time from Brazil. The new species are described and illustrated based on light and scanning electron microscopy and tables with main characteristics of morphologically similar specimens with species collected in Viçosa are provided. Other species belonging to Meliolaceae collected on hosts belonging to the Annonaceae, Meliaceae and Tiliaceae in Brazil also were studied.

  18. Two new species of Psyttalia Walker (Hymenoptera, Braconidae, Opiinae reared from fruit-infesting tephritid (Diptera hosts in Kenya

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    Robert Wharton


    Full Text Available Two species of opiine Braconidae, reared from fruit-infesting Tephritidae in Kenya, are described. Psyttalia masneri sp. n. was reared from fruits of Dracaena fragrans (L. Ker Gawl. (Liliaceae infested with Taomyia marshalli Bezzi in western Kenya. Psyttalia masneri is the only opiine braconid known to attack members of the genus Taomyia. Unusual morphological features of P. masneri and its host are detailed. Psyttalia halidayi sp. n. was reared from fruits of Lettowianthus stellatus Diels (Annonaceae infested with Ceratitis rosa Karsch in coastal Kenya. Psyttalia halidayi is morphologically similar to several described species of Psyttalia that have previously been used in the biological control of tephritid pests. Unlike these other species, P. halidayi can attack and successfully develop on C. rosa, a serious pest of cultivated fruits. A list of valid species in Psyttalia is provided, along with comments on species groups and host records.

  19. What determines species richness of parasitic organisms? A meta-analysis across animal, plant and fungal hosts. (United States)

    Kamiya, Tsukushi; O'Dwyer, Katie; Nakagawa, Shinichi; Poulin, Robert


    Although a small set of external factors account for much of the spatial variation in plant and animal diversity, the search continues for general drivers of variation in parasite species richness among host species. Qualitative reviews of existing evidence suggest idiosyncrasies and inconsistent predictive power for all proposed determinants of parasite richness. Here, we provide the first quantitative synthesis of the evidence using a meta-analysis of 62 original studies testing the relationship between parasite richness across animal, plant and fungal hosts, and each of its four most widely used presumed predictors: host body size, host geographical range size, host population density, and latitude. We uncover three universal predictors of parasite richness across host species, namely host body size, geographical range size and population density, applicable regardless of the taxa considered and independently of most aspects of study design. A proper match in the primary studies between the focal predictor and both the spatial scale of study and the level at which parasite species richness was quantified (i.e. within host populations or tallied across a host species' entire range) also affected the magnitude of effect sizes. By contrast, except for a couple of indicative trends in subsets of the full dataset, there was no strong evidence for an effect of latitude on parasite species richness; where found, this effect ran counter to the general latitude gradient in diversity, with parasite species richness tending to be higher further from the equator. Finally, the meta-analysis also revealed a negative relationship between the magnitude of effect sizes and the year of publication of original studies (i.e. a time-lag bias). This temporal bias may be due to the increasing use of phylogenetic correction in comparative analyses of parasite richness over time, as this correction yields more conservative effect sizes. Overall, these findings point to common underlying

  20. Molecular and morphological analysis reveals five new species of Zygophiala associated with flyspeck signs on plant hosts from China.

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    Liu Gao

    Full Text Available Species in the genus Zygophiala are associated with sooty blotch and flyspeck disease on a wide range of hosts. In this study, 63 Zygophiala isolates collected from flyspeck colonies on a range of plants from several regions of China were used for phylogeny, host range and geographic distribution analysis. Phylogenetic trees were constructed on four genes--internal transcribed spacer (ITS, partial translation elongation factor 1-alpha (TEF, β-tubulin (TUB2, and actin (ACT--both individually and in combination. Isolates were grouped into 11 clades among which five new species, Z. emperorae, Z. trispora, Z. musae, Z. inaequalis and Z. longispora, were described. Species of Zygophiala differed in observed host range and geographic distribution. Z. wisconsinensis and Z. emperorae were the most prevalent throughout the sampled regions of China, whereas Z. trispora, Z. musae, Z. inaequalis and Z. longispora were collected only in southern China. The hosts of Z. wisconsinensis and Z. emperorae were mainly in the family Rosaceae whereas Z. trispora, Z. musae, Z. inaequalis and Z. longispora were found mainly on banana (Musa spp.. Cross inoculation tests provided evidence of host specificity among SBFS species.

  1. Effects of phylogeny, leaf traits, and the altitudinal distribution of host plants on herbivore assemblages on congeneric Acer species. (United States)

    Nakadai, Ryosuke; Murakami, Masashi; Hirao, Toshihide


    Historical, niche-based, and stochastic processes have been proposed as the mechanisms that drive community assembly. In plant-herbivore systems, these processes can correspond to phylogeny, leaf traits, and the distribution of host plants, respectively. Although patterns of herbivore assemblages among plant species have been repeatedly examined, the effects of these factors among co-occurring congeneric host plant species have rarely been studied. Our aim was to reveal the process of community assembly for herbivores by investigating the effects of phylogeny, leaf traits, and the altitudinal distribution of closely related host plants of the genus Acer. We sampled leaf functional traits for 30 Acer species in Japan. Using a newly constructed phylogeny, we determined that three of the six measured leaf traits (leaf thickness, C/N ratio, and condensed tannin content) showed a phylogenetic signal. In a field study, we sampled herbivore communities on 14 Acer species within an elevation gradient and examined relationships between herbivore assemblages and host plants. We found that herbivore assemblages were significantly correlated with phylogeny, leaf traits, phylogenetic signals, and the altitudinal distribution of host plants. Our results indicate that the interaction between historical and current ecological processes shapes herbivore community assemblages.

  2. Persistence of Functional Protein Domains in Mycoplasma Species and their Role in Host Specificity and Synthetic Minimal Life (United States)

    Kamminga, Tjerko; Koehorst, Jasper J.; Vermeij, Paul; Slagman, Simen-Jan; Martins dos Santos, Vitor A. P.; Bijlsma, Jetta J. E.; Schaap, Peter J.


    Mycoplasmas are the smallest self-replicating organisms and obligate parasites of a specific vertebrate host. An in-depth analysis of the functional capabilities of mycoplasma species is fundamental to understand how some of simplest forms of life on Earth succeeded in subverting complex hosts with highly sophisticated immune systems. In this study we present a genome-scale comparison, focused on identification of functional protein domains, of 80 publically available mycoplasma genomes which were consistently re-annotated using a standardized annotation pipeline embedded in a semantic framework to keep track of the data provenance. We examined the pan- and core-domainome and studied predicted functional capability in relation to host specificity and phylogenetic distance. We show that the pan- and core-domainome of mycoplasma species is closed. A comparison with the proteome of the “minimal” synthetic bacterium JCVI-Syn3.0 allowed us to classify domains and proteins essential for minimal life. Many of those essential protein domains, essential Domains of Unknown Function (DUFs) and essential hypothetical proteins are not persistent across mycoplasma genomes suggesting that mycoplasma species support alternative domain configurations that bypass their essentiality. Based on the protein domain composition, we could separate mycoplasma species infecting blood and tissue. For selected genomes of tissue infecting mycoplasmas, we could also predict whether the host is ruminant, pig or human. Functionally closely related mycoplasma species, which have a highly similar protein domain repertoire, but different hosts could not be separated. This study provides a concise overview of the functional capabilities of mycoplasma species, which can be used as a basis to further understand host-pathogen interaction or to design synthetic minimal life. PMID:28224116

  3. Effect of host diversity and species assemblage composition on bovine tuberculosis (bTB) risk in Ethiopian cattle. (United States)

    Sintayehu, Dejene W; Heitkönig, Ignas M A; Prins, Herbert H T; Tessema, Zewdu K; DE Boer, Willem F


    Current theories on diversity-disease relationships describe host species diversity and species identity as important factors influencing disease risk, either diluting or amplifying disease prevalence in a community. Whereas the simple term 'diversity' embodies a set of animal community characteristics, it is not clear how different measures of species diversity are correlated with disease risk. We therefore tested the effects of species richness, Pielou's evenness and Shannon's diversity on bovine tuberculosis (bTB) risk in cattle in the Afar Region and Awash National Park between November 2013 and April 2015. We also analysed the identity effect of a particular species and the effect of host habitat use overlap on bTB risk. We used the comparative intradermal tuberculin test to assess the number of bTB-infected cattle. Our results suggested a dilution effect through species evenness. We found that the identity effect of greater kudu - a maintenance host - confounded the dilution effect of species diversity on bTB risk. bTB infection was positively correlated with habitat use overlap between greater kudu and cattle. Different diversity indices have to be considered together for assessing diversity-disease relationships, for understanding the underlying causal mechanisms. We posit that unpacking diversity metrics is also relevant for formulating disease control strategies to manage cattle in ecosystems characterized by seasonally limited resources and intense wildlife-livestock interactions.

  4. Asymmetric consequences of host plant occupation on the competition between the whiteflies Bemisia tabaci cryptic species MEAM1 and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae)

    DEFF Research Database (Denmark)

    Zhang, Gui-Fen; Lövei, Gabor L; Hu, Man


    BACKGROUND: The two common whitefly species, Bemisia tabaci (Gennadius) MEAM1 and Trialeurodes vaporariorum (Westwood), often co-occur on their host plants. The effect of host plant occupation by one species on later-arriving conspecific individuals or on the other competing species was examined...

  5. Description and host interactions of a new species of Exetasis Walker (Diptera: Acroceridae), with a key to species of the genus. (United States)

    Barneche, Jorge Adrian; Gillung, Jéssica Paula; González, Alda


    Exetasis jujuyensis Gillung sp. nov. (Acroceridae) is described from Argentina and a dichotomous key to species of Exetasis Walker is provided. Detailed observations are presented on the effect of fly larval development on the behavior of the host spider (Acanthoscurria sternalis Pocock (Theraphosidae)).

  6. Resistance to Arrenurus spp. Parasitism in Odonates: Patterns Across Species and Comparisons Between a Resistant and Susceptible Host. (United States)

    Worthen, Wade B; Hart, Thomas M


    Some adult odonates resist parasitism by larval water mites (Arrenurus spp.) with melanotic encapsulation, in which the mite's stylestome is clogged and the mite starves. In summer 2014, we counted the engorged and resisted mites on 2,729 adult odonates sampled by aerial net at 11 water bodies in Greenville Co. and Pickens Co., SC, and tested the hypothesis that the frequency and intensity of resistance correlates with parasite prevalence (the percentage of parasitized hosts). Resistance prevalence (the percentage of parasitized hosts that resisted at least one mite) varied significantly among host species, exceeding 60% for Argia fumipennis(Burmeister) and Celithemis fasciata Kirby but less than 20% for other species. However, neither resistance prevalence nor mean resistance intensity (mean percentage of resisted mites on resisting hosts) correlated with parasite prevalence. We described potential effects of parasitism on host development ofA. fumipennis and Pachydiplax longipennis(Burmeister) by comparing the percent asymmetry of forewing lengths between parasitized and unparasitized individuals. There was no significant difference in asymmetry for either males or females of A. fumipennis, or males of Pa. longipennis(females were not sampled). We also evaluated differences in melanotic encapsulation between A. fumipennis, which readily encapsulates mites in nature, and Pa. longipennis We inserted a 2.0-mm piece of sterile monofilament line into the thorax of captured individuals for 24 h and compared mean gray value scores of inserted and emergent ends using Image-J software. There was no difference in melanotic encapsulation between species.



    Yoshiyasu, Yutaka; Hirai, Kazuo; Takeda, Makio; Cassanello, A.M.Lajarthe; Maramag, A.Z.; Yao, N-Zue


    アワノメイガの生物防除素材としてのTrichogramma ostriniaeの大量増殖のための代替寄主を探索した。鱗翅目5種、直翅目1種、ゴキブリ目1種、双翅目1種を調べた結果、発育速度、出てくるハチの大きさ、寄生率から判断してハチノスツヅリガが最適であるという結論に達した。このハチはコナガのような小さい卵も攻撃したが、湿気ある卵は攻撃しなかった。ゴキブリ、コオロギ、タマネギバエはこの理由で不適と判断された。サクサンは中国で大量飼育の材料に使われているが、近縁のヤママユガからは羽化する個体が得られなかった。 / Alternative host species were sought for mass production of Trichogramma ostriniae. Out of 5 lepidopterans, 1 orthopteran, 1 dictyopteran and 1 dipteran species that were examined, Galleria mellonella was found to be the material of choi...

  8. Enemy-free space promotes maintenance of host races in an aphid species. (United States)

    Vosteen, Ilka; Gershenzon, Jonathan; Kunert, Grit


    The enormous biodiversity of herbivorous insects may arise from ecological speciation via continuous host-plant switches. Whether such switches are successful depends on the trade-off between different selection pressures that act on herbivores. Decreased herbivore performance due to suboptimal nutrition might be compensated for by a reduced natural enemy pressure. As a consequence, an "enemy-free space" on a certain plant might facilitate host-plant switches and maintain biotypes. To test this hypothesis, we used the pea aphid (Acyrthosiphon pisum) complex, which consists of at least 11 genetically distinct host races that are native to specific legume host plants but can all develop on the universal host plant Vicia faba. Three A. pisum host races native to Trifolium pratense, Pisum sativum, and Medicago sativa were investigated in experiments on their respective host plants and on the universal host plant V. faba. We found that hoverflies preferred to oviposit on P. sativum and the universal host V. faba. Since feeding by hoverfly larvae suppressed aphid population growth on these host plants, the native hosts M. sativa and T. pratense provided enemy-free space for the respective A. pisum races. Mobile predators, such as ants and ladybird beetles, preferred Pisum race aphids on V. faba over P. sativum. Thus, all three of the native host plants studied supply enemy-free space for A. pisum compared to the universal host V. faba. Reducing encounters between aphid races on V. faba would reduce gene flow among them and could contribute to maintaining the host races.

  9. Phylogenetic analysis of European species of Proteocephalus (Cestoda: Proteocephalidea): compatibility of molecular and morphological data, and parasite-host coevolution. (United States)

    Skeríková, A; Hypsa, V; Scholz, T V


    The phylogeny of European species of the tapeworm genus Proteocephalus was studied, based on partial 18S rDNA and morphological data. The group was found to be monophyletic. The analysis showed a low informative value of available morphological characters in comparison with molecular data. The morphological matrix resulted in a poorly resolved tree which is, however, compatible with the topology (Proteocephalus osculatus (Proteocephalus torulosus (Proteocephalus macrocephalus, Proteocephalus filicollis) (Proteocephalus tetrastomus, Proteocephalus percae, Proteocephalus longicollis))) based on the 18S rDNA data. A comparison performed by the program TreeMap showed a lack of significant congruency between parasite and host phylogenies. Therefore, the distribution of species in their hosts appears to be independent of the phylogeny and it is likely to be a result of host-switching, rather than co-speciation events.

  10. Comparisons of host mitochondrial, nuclear and endosymbiont bacterial genes reveal cryptic fig wasp species and the effects of Wolbachia on host mtDNA evolution and diversity

    Directory of Open Access Journals (Sweden)

    Feng Gui


    Full Text Available Abstract Background Figs and fig-pollinating wasp species usually display a highly specific one-to-one association. However, more and more studies have revealed that the "one-to-one" rule has been broken. Co-pollinators have been reported, but we do not yet know how they evolve. They may evolve from insect speciation induced or facilitated by Wolbachia which can manipulate host reproduction and induce reproductive isolation. In addition, Wolbachia can affect host mitochondrial DNA evolution, because of the linkage between Wolbachia and associated mitochondrial haplotypes, and thus confound host phylogeny based on mtDNA. Previous research has shown that fig wasps have the highest incidence of Wolbachia infection in all insect taxa, and Wolbachia may have great influence on fig wasp biology. Therefore, we look forward to understanding the influence of Wolbachia on mitochondrial DNA evolution and speciation in fig wasps. Results We surveyed 76 pollinator wasp specimens from nine Ficus microcarpa trees each growing at a different location in Hainan and Fujian Provinces, China. We found that all wasps were morphologically identified as Eupristina verticillata, but diverged into three clades with 4.22-5.28% mtDNA divergence and 2.29-20.72% nuclear gene divergence. We also found very strong concordance between E. verticillata clades and Wolbachia infection status, and the predicted effects of Wolbachia on both mtDNA diversity and evolution by decreasing mitochondrial haplotypes. Conclusions Our study reveals that the pollinating wasp E. verticillata on F. microcarpa has diverged into three cryptic species, and Wolbachia may have a role in this divergence. The results also indicate that Wolbachia strains infecting E. verticillata have likely resulted in selective sweeps on host mitochondrial DNA.

  11. Recurrent evolution of host and vector association in bacteria of the Borrelia burgdorferi sensu lato species complex. (United States)

    Becker, Noémie S; Margos, Gabriele; Blum, Helmut; Krebs, Stefan; Graf, Alexander; Lane, Robert S; Castillo-Ramírez, Santiago; Sing, Andreas; Fingerle, Volker


    The Borrelia burgdorferi sensu lato (s.l.) species complex consists of tick-transmitted bacteria and currently comprises approximately 20 named and proposed genospecies some of which are known to cause Lyme Borreliosis. Species have been defined via genetic distances and ecological niches they occupy. Understanding the evolutionary relationship of species of the complex is fundamental to explaining patterns of speciation. This in turn forms a crucial basis to frame testable hypotheses concerning the underlying processes including host and vector adaptations. Illumina Technology was used to obtain genome-wide sequence data for 93 strains of 14 named genospecies of the B. burgdorferi species complex and genomic data already published for 18 additional strain (including one new species) was added. Phylogenetic reconstruction based on 114 orthologous single copy genes shows that the genospecies represent clearly distinguishable taxa with recent and still ongoing speciation events apparent in Europe and Asia. The position of Borrelia species in the phylogeny is consistent with host associations constituting a major driver for speciation. Interestingly, the data also demonstrate that vector associations are an additional driver for diversification in this tick-borne species complex. This is particularly obvious in B. bavariensis, a rodent adapted species that has diverged from the bird-associated B. garinii most likely in Asia. It now consists of two populations one of which most probably invaded Europe following adaptation to a new vector (Ixodes ricinus) and currently expands its distribution range. The results imply that genotypes/species with novel properties regarding host or vector associations have evolved recurrently during the history of the species complex and may emerge at any time. We suggest that the finding of vector associations as a driver for diversification may be a general pattern for tick-borne pathogens. The core genome analysis presented here

  12. Prey preference and host suitability of the predatory and parasitoid carabid beetle, Lebia grandis, for several species of Leptinotarsa beetles. (United States)

    Weber, Donald C; Rowley, Daniel L; Greenstone, Matthew H; Athanas, Michael M


    Lebia grandis (Coleoptera: Carabidae), recorded as a parasitoid only on Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae), is capable of parasitizing the false potato beetle, L. juncta, and also L. haldemani. Historical records show that L. decemlineata, while the only recorded host, was not present in much of the original range of L. grandis, and may not have been its host prior to its expansion into eastern North America, where L. juncta is endemic. Our laboratory comparisons suggest that L. juncta, the presumptive original host, best supports the development of the parasitoid larval L. grandis, based on 43.6% successful emergence of the adult carabid parasitoid, compared to 11.5% from the two other Leptinotarsa species. L. grandis adults accept eggs and larvae of all 3 Leptinotarsa species as adult food. Naive, newly-emerged adults show no preference when presented the 3 species of third-instar larvae, which they consume at a mean rate of 3.3 per day, a rate which does not differ significantly by sex, larval host, or weight at emergence. When presented with equal amounts by weight of the 3 species of Leptinotarsa eggs, such adults consume the equivalent of 23.0 L. decemlineata eggs per day, with consumption of L. juncta eggs 67% higher by weight than L. decemlineata consumption. Insight into the biotic and abiotic limitations on L. grandis should aid in determining its potential for suppression of Colorado potato beetle by biological control in diverse agroecosystems.

  13. Does a facultative precocious life cycle predispose the marine trematode Proctoeces cf. lintoni to inbreeding and genetic differentiation among host species? (United States)

    Valdivia, I M; Criscione, C D; Cárdenas, L; Durán, C P; Oliva, M E


    Intraspecific variability in parasite life cycle complexity (number of hosts and species of hosts in the life cycle) may have an impact how parasite genetic variation is partitioned among individual parasites, host individuals or host species within a given area. Among digenean trematodes, a three-host life cycle is common. However, a few species are precocious and may reach sexual maturity in what is typically regarded as the second intermediate host. The objective of this study was to determine whether a precocious life cycle predisposes digeneans to possible inbreeding or genetic subdivision among host species. As a study system, we used the digenean Proctoeces cf. lintoni whose metacercariae precociously mature (facultative) without a cyst wall in the gonads of multiple sympatric species of keyhole limpets (Fissurella spp.), typically regarded as the second intermediate hosts. Genotyped parasites were collected from four species of limpets and the clingfish Sicyases sanguineus, the third and final host where sexual maturity occurs. We found very high microsatellite diversity, Hardy-Weinberg equilibrium over all genotyped individuals, and little to no genetic structuring among parasites collected from the different host species. The fact that metacercariae do not encyst in the keyhole limpets, coupled with the high mixing potential of an aquatic environment, likely promote panmixia in local populations of P. cf. lintoni.

  14. Host plant species determines symbiotic bacterial community mediating suppression of plant defenses (United States)

    Chung, Seung Ho; Scully, Erin D.; Peiffer, Michelle; Geib, Scott M.; Rosa, Cristina; Hoover, Kelli; Felton, Gary W.


    Herbivore associated bacteria are vital mediators of plant and insect interactions. Host plants play an important role in shaping the gut bacterial community of insects. Colorado potato beetles (CPB; Leptinotarsa decemlineata) use several Solanum plants as hosts in their natural environment. We previously showed that symbiotic gut bacteria from CPB larvae suppressed jasmonate (JA)-induced defenses in tomato. However, little is known about how changes in the bacterial community may be involved in the manipulation of induced defenses in wild and cultivated Solanum plants of CPB. Here, we examined suppression of JA-mediated defense in wild and cultivated hosts of CPB by chemical elicitors and their symbiotic bacteria. Furthermore, we investigated associations between the gut bacterial community and suppression of plant defenses using 16 S rRNA amplicon sequencing. Symbiotic bacteria decreased plant defenses in all Solanum hosts and there were different gut bacterial communities in CPB fed on different host plants. When larvae were reared on different hosts, defense suppression differed among host plants. These results demonstrate that host plants influence herbivore gut bacterial communities and consequently affect the herbivore’s ability to manipulate JA-mediated plant defenses. Thus, the presence of symbiotic bacteria that suppress plant defenses might help CPB adapt to host plants. PMID:28045052

  15. Genetic characterization of flea-derived Bartonella species from native animals in Australia suggests host-parasite co-evolution. (United States)

    Kaewmongkol, Gunn; Kaewmongkol, Sarawan; McInnes, Linda M; Burmej, Halina; Bennett, Mark D; Adams, Peter J; Ryan, Una; Irwin, Peter J; Fenwick, Stanley G


    Fleas are important arthropod vectors for a variety of diseases in veterinary and human medicine, and bacteria belonging to the genus Bartonella are among the organisms most commonly transmitted by these ectoparasites. Recently, a number of novel Bartonella species and novel species candidates have been reported in marsupial fleas in Australia. In the present study the genetic diversity of marsupial fleas was investigated; 10 species of fleas were collected from seven different marsupial and placental mammal hosts in Western Australia including woylies (Bettongia penicillata), western barred bandicoots (Perameles bougainville), mardos (Antechinus flavipes), bush rats (Rattus fuscipes), red foxes (Vulpes vulpes), feral cats (Felis catus) and rabbits (Oryctolagus cuniculus). PCR and sequence analysis of the cytochrome oxidase subunit I (COI) and the 18S rRNA genes from these fleas was performed. Concatenated phylogenetic analysis of the COI and 18S rRNA genes revealed a close genetic relationship between marsupial fleas, with Pygiopsylla hilli from woylies, Pygiopsylla tunneyi from western barred bandicoots and Acanthopsylla jordani from mardos, forming a separate cluster from fleas collected from the placental mammals in the same geographical area. The clustering of Bartonella species with their marsupial flea hosts suggests co-evolution of marsupial hosts, marsupial fleas and Bartonella species in Australia.

  16. PHI-base: a new interface and further additions for the multi-species pathogen-host interactions database. (United States)

    Urban, Martin; Cuzick, Alayne; Rutherford, Kim; Irvine, Alistair; Pedro, Helder; Pant, Rashmi; Sadanadan, Vidyendra; Khamari, Lokanath; Billal, Santoshkumar; Mohanty, Sagar; Hammond-Kosack, Kim E


    The pathogen-host interactions database (PHI-base) is available at PHI-base contains expertly curated molecular and biological information on genes proven to affect the outcome of pathogen-host interactions reported in peer reviewed research articles. In addition, literature that indicates specific gene alterations that did not affect the disease interaction phenotype are curated to provide complete datasets for comparative purposes. Viruses are not included. Here we describe a revised PHI-base Version 4 data platform with improved search, filtering and extended data display functions. A PHIB-BLAST search function is provided and a link to PHI-Canto, a tool for authors to directly curate their own published data into PHI-base. The new release of PHI-base Version 4.2 (October 2016) has an increased data content containing information from 2219 manually curated references. The data provide information on 4460 genes from 264 pathogens tested on 176 hosts in 8046 interactions. Prokaryotic and eukaryotic pathogens are represented in almost equal numbers. Host species belong ∼70% to plants and 30% to other species of medical and/or environmental importance. Additional data types included into PHI-base 4 are the direct targets of pathogen effector proteins in experimental and natural host organisms. The curation problems encountered and the future directions of the PHI-base project are briefly discussed. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. Sequential utilization of hosts from different fly families by genetically distinct, sympatric populations within the Entomophthora muscae species complex.

    Directory of Open Access Journals (Sweden)

    Andrii P Gryganskyi

    Full Text Available The fungus Entomophthora muscae (Entomophthoromycota, Entomophthorales, Entomophthoraceae is a widespread insect pathogen responsible for fatal epizootic events in many dipteran fly hosts. During epizootics in 2011 and 2012 in Durham, North Carolina, we observed a transition of fungal infections from one host, the plant-feeding fly Delia radicum, to a second host, the predatory fly Coenosia tigrina. Infections first appeared on Delia in the middle of March, but by the end of May, Coenosia comprised 100% of infected hosts. Multilocus sequence typing revealed that E. muscae in Durham comprises two distinct subpopulations (clades with several haplotypes in each. Fungi from either clade are able to infect both fly species, but vary in their infection phenologies and host-specificities. Individuals of the more phylogenetically diverse clade I predominated during the beginning of the spring epizootic, infecting mostly phytophagous Delia flies. Clade II dominated in late April and May and affected mostly predatory Coenosia flies. Analysis of population structure revealed two subpopulations within E. muscae with limited gene exchange. This study provides the first evidence of recombination and population structure within the E. muscae species complex, and illustrates the complexity of insect-fungus relationships that should be considered for development of biological control methods.

  18. Plant Killing by Mutualistic Ants Increases the Density of Host Species Seedlings in the Dry Forest of Costa Rica

    Directory of Open Access Journals (Sweden)

    Sabrina Amador-Vargas


    Full Text Available Some species of plant-mutualistic ants kill the vegetation growing in the vicinities of their host plant, creating an area of bare ground (clearing. The reduced competition in the clearing may facilitate the establishment of host species sprouts (clones and seedlings, which in turn benefits the ants with additional food and shelter (“sprout-establishment hypothesis”. To test this hypothesis, the density and origin of Acacia collinsii sprouts growing inside clearings and in the vicinities of acacia plants without clearings were compared. Also, to assess the pruning selectivity of acacia ants (Pseudomyrmex spinicola, seedlings were transplanted into clearings. The reaction of ants towards unrewarding acacia seedlings (without food and shelter was also tested. The density of acacia sprouts growing inside clearings was almost twice that in the vicinities of host plants without clearings, and sprouts were inhabited by nestmates of the colony that made the clearing. Clones and seedlings were found in similar proportions in the clearings, and ants did not kill unrewarding acacia seedlings or seedlings unrelated to their host. The benefit reported here for the ants could be in conflict with the host plant, especially when the plant has rhizomal reproduction.

  19. PHI-base: a new interface and further additions for the multi-species pathogen–host interactions database (United States)

    Urban, Martin; Cuzick, Alayne; Rutherford, Kim; Irvine, Alistair; Pedro, Helder; Pant, Rashmi; Sadanadan, Vidyendra; Khamari, Lokanath; Billal, Santoshkumar; Mohanty, Sagar; Hammond-Kosack, Kim E.


    The pathogen–host interactions database (PHI-base) is available at PHI-base contains expertly curated molecular and biological information on genes proven to affect the outcome of pathogen–host interactions reported in peer reviewed research articles. In addition, literature that indicates specific gene alterations that did not affect the disease interaction phenotype are curated to provide complete datasets for comparative purposes. Viruses are not included. Here we describe a revised PHI-base Version 4 data platform with improved search, filtering and extended data display functions. A PHIB-BLAST search function is provided and a link to PHI-Canto, a tool for authors to directly curate their own published data into PHI-base. The new release of PHI-base Version 4.2 (October 2016) has an increased data content containing information from 2219 manually curated references. The data provide information on 4460 genes from 264 pathogens tested on 176 hosts in 8046 interactions. Prokaryotic and eukaryotic pathogens are represented in almost equal numbers. Host species belong ∼70% to plants and 30% to other species of medical and/or environmental importance. Additional data types included into PHI-base 4 are the direct targets of pathogen effector proteins in experimental and natural host organisms. The curation problems encountered and the future directions of the PHI-base project are briefly discussed. PMID:27915230

  20. Comparative studies on codon usage pattern of chloroplasts and their host nuclear genes in four plant species

    Indian Academy of Sciences (India)

    Qingpo Liu; Qingzhong Xue


    A detailed comparison was made of codon usage of chloroplast genes with their host (nuclear) genes in the four angiosperm species Oryza sativa, Zea mays, Triticum aestivum and Arabidopsis thaliana. The average GC content of the entire genes, and at the three codon positions individually, was higher in nuclear than in chloroplast genes, suggesting different genomic organization and mutation pressures in nuclear and chloroplast genes. The results of Nc-plots and neutrality plots suggested that nucleotide compositional constraint had a large contribution to codon usage bias of nuclear genes in O. sativa, Z. mays, and T. aestivum, whereas natural selection was likely to be playing a large role in codon usage bias in chloroplast genomes. Correspondence analysis and chi-test showed that regardless of the genomic environment (species) of the host, the codon usage pattern of chloroplast genes differed from nuclear genes of their host species by their AU-richness. All the chloroplast genomes have predominantly A- and/or U-ending codons, whereas nuclear genomes have G-, C- or U-ending codons as their optimal codons. These findings suggest that the chloroplast genome might display particular characteristics of codon usage that are different from its host nuclear genome. However, one feature common to both chloroplast and nuclear genomes in this study was that pyrimidines were found more frequently than purines at the synonymous codon position of optimal codons.

  1. Composition of the Cutaneous Bacterial Community in Japanese Amphibians: Effects of Captivity, Host Species, and Body Region. (United States)

    Sabino-Pinto, Joana; Bletz, Molly Catherine; Islam, Mohammed Mafizul; Shimizu, Norio; Bhuju, Sabin; Geffers, Robert; Jarek, Michael; Kurabayashi, Atsushi; Vences, Miguel


    The cutaneous microbiota plays a significant role in the biology of their vertebrate hosts, and its composition is known to be influenced both by host and environment, with captive conditions often altering alpha diversity. Here, we compare the cutaneous bacterial communities of 61 amphibians (both wild and captive) from Hiroshima, Japan, using high-throughput amplicon sequencing of a segment of the 16S rRNA gene. The majority of these samples came from a captive breeding facility at Hiroshima University where specimens from six species are maintained under highly standardized conditions for several generations. This allowed to identify host effects on the bacterial communities under near identical environmental conditions in captivity. We found the structure of the cutaneous bacterial community significantly differing between wild and captive individuals of newts, Cynops pyrrhogaster, with a higher alpha diversity found in the wild individuals. Community structure also showed distinct patterns when comparing different species of amphibians kept under highly similar conditions, revealing an intrinsic host effect. Bacterial communities of dorsal vs. ventral skin surfaces did not significantly differ in most species, but a trend of higher alpha diversity on the ventral surface was found in Oriental fire-bellied toads, Bombina orientalis. This study confirms the cutaneous microbiota of amphibians as a highly dynamic system influenced by a complex interplay of numerous factors.

  2. Ultra-deep sequencing of intra-host rabies virus populations during cross-species transmission.

    Directory of Open Access Journals (Sweden)

    Monica K Borucki


    Full Text Available One of the hurdles to understanding the role of viral quasispecies in RNA virus cross-species transmission (CST events is the need to analyze a densely sampled outbreak using deep sequencing in order to measure the amount of mutation occurring on a small time scale. In 2009, the California Department of Public Health reported a dramatic increase (350 in the number of gray foxes infected with a rabies virus variant for which striped skunks serve as a reservoir host in Humboldt County. To better understand the evolution of rabies, deep-sequencing was applied to 40 unpassaged rabies virus samples from the Humboldt outbreak. For each sample, approximately 11 kb of the 12 kb genome was amplified and sequenced using the Illumina platform. Average coverage was 17,448 and this allowed characterization of the rabies virus population present in each sample at unprecedented depths. Phylogenetic analysis of the consensus sequence data demonstrated that samples clustered according to date (1995 vs. 2009 and geographic location (northern vs. southern. A single amino acid change in the G protein distinguished a subset of northern foxes from a haplotype present in both foxes and skunks, suggesting this mutation may have played a role in the observed increased transmission among foxes in this region. Deep-sequencing data indicated that many genetic changes associated with the CST event occurred prior to 2009 since several nonsynonymous mutations that were present in the consensus sequences of skunk and fox rabies samples obtained from 20032010 were present at the sub-consensus level (as rare variants in the viral population in skunk and fox samples from 1995. These results suggest that analysis of rare variants within a viral population may yield clues to ancestral genomes and identify rare variants that have the potential to be selected for if environment conditions change.

  3. Screening low fire blight susceptible Crataegus species for host suitability to hawthorn leaf-curling aphids (Dysaphis spp.). (United States)

    Bribosia, E; Bylemans, D; Van Impe, G; Migon, M


    The group of hawthorn leaf-curling aphids (Dysaphis spp.) hosted by the common hawthorn Crataegus monogyna Jacq. may play an important role in the biological control of the rosy apple aphid, Dysaphis plantaginea (Passerini), by increasing reproduction opportunities for the indigenous hymenopteran parasitoid Ephedrus persicae Froggatt. Unfortunately, most fruitgrowers hesitate to introduce the common hawthorn in their orchards because they fear fire blight infections which may be transmitted by this highly susceptible hawthron species. This potential hazard led us to investigate the suitability to leaf-curling aphids of alternative Crataegus species. As representative for these closely-related aphids, the species Dysaphis apiifolia petroselini (Börner) was used in the trials. Ten Crataegus species characterized by their very low susceptibility to fire blight were examined from two angles. Firstly, aphid sexuals were introduced in autumn onto the different species to verify whether egg laying could take place. Secondly, the development of fundatrices and gall formation were followed the next spring. Although eggs and mature fundatrices could be obtained on almost all species, no fundatrice-hosting galls were recorded in spring. The possible causes of these negative results with respect to the geographical origin of the particular Crataegus species involved in this work are discussed.

  4. The influence of interspecific competition and host preference on the phylogeography of two African ixodid tick species. (United States)

    Cangi, Nídia; Horak, Ivan G; Apanaskevich, Dmitry A; Matthee, Sonja; das Neves, Luís C B G; Estrada-Peña, Agustín; Matthee, Conrad A


    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.

  5. The influence of interspecific competition and host preference on the phylogeography of two African ixodid tick species.

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    Nídia Cangi

    Full Text Available 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.

  6. Host plant species determines symbiotic bacterial community mediating suppression of plant defenses (United States)

    Herbivore associated bacteria are vital mediators of plant and insect interactions. Host plants play an important role in shaping the gut bacterial community of insects. Colorado potato beetles (CPB; Leptinotarsa decemlineata) use several Solanum plants as hosts in their natural environment. We prev...

  7. Relationships between host species and morphometric patterns in Fasciola hepatica adults and eggs from the northern Bolivian Altiplano hyperendemic region. (United States)

    Valero, M A; Darce, N A; Panova, M; Mas-Coma, S


    The highest prevalences and intensities of human fasciolosis by Fasciola hepatica are found in the northern Bolivian Altiplano, where sheep and cattle are the main reservoir host species and pigs and donkeys the secondary ones. Morphometric comparisons of many linear measurements, areas and ratios of F. hepatica adults (from sheep, cattle and pigs) and eggs (from sheep, cattle, pigs and donkeys) in natural liver fluke populations of the Bolivian Altiplano, as well as of F. hepatica adults and eggs experimentally obtained in Wistar rats infected with Altiplanic sheep, cattle and pig isolates, were made using computer image analysis and an allometric model. Although morphometric values of adult flukes from natural populations of sheep, cattle, and pigs showed great overlap, there were clear differences in allometric growth. The allometries analyzed were: body area (BA) versus body length (BL), BA versus body width (BW), BA versus perimeter (Pe), BA versus distance between posterior end of body and ventral sucker (P-VS), BL versus BW, BL versus Pe, and BL versus P-VS. These allometries show a good fit in the seven pairs of variables in all the populations examined. Comparative statistical analysis of the allometries shows that fluke adult populations from sheep, cattle and pigs significantly differ in BL versus BW and BL versus P-VS functions. Statistical analysis of F. hepatica egg size shows characteristic morphometric traits in each definitive host species. In experimentally infected rats, fluke adult allometry and egg morphometry do not vary depending on the Altiplanic definitive host species isolate. Our study reveals that the definitive host species decisively influences the size of F. hepatica adults and eggs, and these influences do not persist in a rodent definitive host model.

  8. Multilocus sequence typing of a global collection of Pasteurella multocida isolates from cattle and other host species demonstrates niche association

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    Lainson F Alex


    Full Text Available Abstract Background Pasteurella multocida causes disease in many host species throughout the world. In bovids, it contributes to bovine respiratory disease (BRD and causes haemorrhagic septicaemia (HS. Previous studies have suggested that BRD-associated P. multocida isolates are of limited diversity. A multilocus sequence typing (MLST scheme for P. multocida was used to determine whether the low levels of diversity reported are due to the limited discriminatory power of the typing method used, restricted sample selection or true niche association. Bovine respiratory isolates of P. multocida (n = 133 from the UK, the USA and France, collected between 1984 and 2008 from both healthy and clinically affected animals, were typed using MLST. Isolates of P. multocida from cases of HS, isolates from other host species and data from the MLST database were used as comparison. Results Bovine respiratory isolates were found to be clonal (ISA 0.45 with 105/128 belonging to clonal complex 13 (CC13. HS isolates were not related to bovine respiratory isolates. Of the host species studied, the majority had their own unique sequence types (STs, with few STs being shared across host species, although there was some cross over between porcine and bovine respiratory isolates. Avian, ovine and porcine isolates showed greater levels of diversity compared to cattle respiratory isolates, despite more limited geographic origins. Conclusions The homogeneity of STs of bovine respiratory P. multocida observed, and the differences between these and P. multocida subpopulations from bovine non-respiratory isolates and non-bovine hosts may indicate niche association.

  9. Host species and environmental effects on bacterial communities associated with Drosophila in the laboratory and in the natural environment.

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    Fabian Staubach

    Full Text Available The fruit fly Drosophila is a classic model organism to study adaptation as well as the relationship between genetic variation and phenotypes. Although associated bacterial communities might be important for many aspects of Drosophila biology, knowledge about their diversity, composition, and factors shaping them is limited. We used 454-based sequencing of a variable region of the bacterial 16S ribosomal RNA gene to characterize the bacterial communities associated with wild and laboratory Drosophila isolates. In order to specifically investigate effects of food source and host species on bacterial communities, we analyzed samples from wild Drosophila melanogaster and D. simulans collected from a variety of natural substrates, as well as from adults and larvae of nine laboratory-reared Drosophila species. We find no evidence for host species effects in lab-reared flies; instead, lab of origin and stochastic effects, which could influence studies of Drosophila phenotypes, are pronounced. In contrast, the natural Drosophila-associated microbiota appears to be predominantly shaped by food substrate with an additional but smaller effect of host species identity. We identify a core member of this natural microbiota that belongs to the genus Gluconobacter and is common to all wild-caught flies in this study, but absent from the laboratory. This makes it a strong candidate for being part of what could be a natural D. melanogaster and D. simulans core microbiome. Furthermore, we were able to identify candidate pathogens in natural fly isolates.

  10. Evaluating the Biological and Ecological Factors Influencing Transmission of Larval Digenetic Trematodes: A Test of Second Intermediate Host Specificity of Two North American Halipegus Species. (United States)

    Stigge, Heather A; Bolek, Matthew G


    Host specificity of parasites is a basic principle in parasitology; however, it is not easily measured. Previously, host specificity was calculated as the number of species that a parasite infected, but this is not an accurate description of host usage because some species are capable of being infected but do not contribute to the completion of the life cycle. Instead, measures of host specificity should take into consideration interactions between a parasite and a potential host species as well as interactions between current and subsequent hosts in the life cycle. The objectives of this study were to track the development of 2 trematode species, Halipegus eccentricus and Halipegus occidualis , in 3 phylogenetically and ecologically distinct microcrustacean second intermediate hosts, and then evaluate the extent to which each of these hosts contributed to transmission of each Halipegus species to the next odonate host in the life cycle. All 3 microcrustacean species exposed became infected with both species of Halipegus. The patterns of growth of H. eccentricus and H. occidualis were similar, but there were consistent differences in the rates of growth among the microcrustacean species in both Halipegus species. Regardless of host species infected, all individuals of both species were considered to be developmentally infective to the next host in the life cycle by 19 days postexposure (DPE) when they lost their excretory bladder. Worms of varying sizes were capable of surviving without this structure, suggesting that there is not a strong relationship between the rate of growth of the metacercariae and the development of their osmoregulatory system. Although Halipegus species were capable of living without an excretory bladder at 19 DPE, there were differences in their size and rates at which the 3 microcrustaceans contributed to transmission of the parasites to subsequent odonate hosts. Collectively, under controlled laboratory conditions, there was an

  11. Host specificity of Oschmarinella rochebruni and Brachycladium atlanticum (Digenea: Brachycladiidae) in five cetacean species from western Mediterranean waters. (United States)

    Mateu, P; Raga, J A; Aznar, F J


    We investigated patterns of specificity of liver flukes (fam. Brachycladiidae) in a community of cetaceans from the western Mediterranean. The liver and pancreas of 103 striped dolphins, Stenella coeruleoalba, 18 Risso's dolphins, Grampus griseus, 14 bottlenose dolphins, Tursiops truncatus, 8 common dolphins, Delphinus delphis, and 5 long-finned pilot whales, Globicephala melas, were analysed for brachycladiid species. Two species were found: Oschmarinella rochebruni in striped dolphins (prevalence (P): 61.2%; mean intensity (MI) (95% CI): 34.2 (25.7-45.6)), and Brachycladium atlanticum in striped dolphins (P: 39.8%; MI: 7.1 (4.8-13.1)) and a single individual of common dolphin (P: 12.5%; intensity: 19), which represents a new host record. A molecular analysis using the internal transcribed spacer 2 (ITS2) region of the rDNA gene confirmed that specimens of B. atlanticum were conspecific regardless of host species. Available dietary data suggest that Risso's dolphins, bottlenose dolphins and long-finned pilot whales would contact rarely, if at all, the infective stages of O. rochebruni and B. atlanticum. Neither the prevalence nor the mean abundance of B. atlanticum differed significantly between striped and common dolphins, but a principal component analysis using seven morphometric variables indicated that specimens collected from the common dolphin were stunted. These worms also had fewer eggs compared with specimens typically found in striped dolphins, although the size of the eggs was similar in both host species. Dwarfism and low fecundity have typically been found in helminths infecting unusual host species, and might reflect the lower compatibility of B. atlanticum for common dolphins. In summary, both O. rochebruni and B. atlanticum appear to exhibit a narrow specificity for striped dolphins in the western Mediterranean.

  12. Molecular phylogenetics, systematics and host-plant associations of the Bruchidius albosparsus (Fåhraeus) species group (Coleoptera, Chrysomelidae, Bruchinae) with the description of four new species. (United States)

    Delobel, Alex; Le Ru, Bruno; Genson, Gwenaëlle; Musyoka, Boaz K; Kergoat, Gael J


    Bruchidius Schilsky is a large paraphyletic genus of seed beetles (Coleoptera: Chrysomelidae: Bruchinae) which consists of multiple lineages that are usually associated with narrow sets of host-plants. In this study we focus on a group that mostly develops on wattle trees (acacias) belonging to the genus Vachellia Wight & Arn. This group originally included nine species and was designated as the Bruchidius centromaculatus (Allard) species group, but recent phylogenetic analyses revealed that these species belong to a much wider group of species with similar morphologies. For reasons of anteriority we call this enlarged group Bruchidius albosparsus (Fåhraeus). Here we review the morphology of species in this group and provide new diagnoses and ecological data for 10 species. The following combinations and synonymies are proposed: Bruchidius tanaensis (Pic, 1921) (= Bruchus tanaensis Pic, 1921) comb. nov. and Bruchidius albosparsus (Fåhraeus, 1839) (= Bruchus spadiceus Fåhraeus, 1839) syn. nov. Four new species are also described: B. eminingensis sp. nov., B. gerrardiicola sp. nov., B. glomeratus sp. nov. and B. haladai sp. nov. Finally we carried out molecular phylogenetic analyses on a multi-marker dataset of 59 specimens and 35 species, including 14 species from the group. The resulting trees allow us to confirm the monophyly of the group of interest and provide a more detailed picture of their evolutionary relationships.

  13. A new species of Longitarsus Latreille, 1829 (Coleoptera, Chrysomelidae, Galerucinae pupating inside stem aerenchyma of the hydrophyte host from the Oriental Region

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    Kaniyarikkal Prathapan


    Full Text Available A new species of subaquatic Longitarsus pupating inside the stem aerenchyma of its hydrophyte host plant is described. Eggs are laid on tender leaves and buds and the larvae are open feeders. This is the first report of an Oriental flea beetle pupating inside the stem of its hydrophyte host. A key to the species of southern Indian Longitarsus is provided.

  14. Host Preference by Monochamus alternatus (Hope) during Maturation Feeding on Pine Species and Masson Pine Provenances

    Institute of Scientific and Technical Information of China (English)


    Host preferences pine of the sawyer beetle, Monochamus alternates (Hope), during maturation feeding on 8 conifer trees and 40 masson pine provenances, were investigated using 3 types of laboratory bioassay of consistent feeding preference, feeding area and visitation frequency. M. alternatus adults have the highest frequency of feeding and prefer to feed on the branches of P. massoniana and P. densiflora and had significant host selectivity on 8 conifer trees in the area of Nanjing. The adult feeding vi...

  15. Assessing host-parasite specificity through coprological analysis: a case study with species of Corynosoma (Acanthocephala: Polymorphidae) from marine mammals. (United States)

    Aznar, F J; Hernández-Orts, J; Suárez, A A; García-Varela, M; Raga, J A; Cappozzo, H L


    In this paper we report an investigation of the utility of coprological analysis as an alternative technique to study parasite specificity whenever host sampling is problematic; acanthocephalans from marine mammals were used as a model. A total of 252 scats from the South American sea lion, Otaria flavescens, and rectal faeces from 43 franciscanas, Pontoporia blainvillei, from Buenos Aires Province, were examined for acanthocephalans. Specimens of two species, i.e. Corynosoma australe and C. cetaceum, were collected from both host species. In sea lions, 78 out of 145 (37.9%) females of C. australe were gravid and the sex ratio was strongly female-biased. However, none of the 168 females of C. cetaceum collected was gravid and the sex ratio was not female-biased. Conversely, in franciscanas, 14 out of 17 (82.4%) females of C. cetaceum were gravid, but none of 139 females of C. australe was, and the sex ratio of C. cetaceum, but not that of C. australe, was female-biased. In putative non-hosts, the size of worms was similar to that from specimens collected from prey. Results suggest that both acanthocephalans contact sea lions and franciscanas regularly. However, C. australe and C. cetaceum cannot apparently reproduce, nor even grow, in franciscanas and sea lions, respectively. Coprological analysis may represent a useful supplementary method to investigate parasite specificity, particularly when host carcasses are difficult to obtain.

  16. Multilocus sequence typing of a global collection of pasteurella multocida isolates from cattle and other host species demonstrates niche association


    Hotchkiss, E.J.; Hodgson, J.C.; Lainson, F. A.; Zadoks, R.N.


    Abstract Background Pasteurella multocida causes disease in many host species throughout the world. In bovids, it contributes to bovine respiratory disease (BRD) and causes haemorrhagic septicaemia (HS). Previous studies have suggested that BRD-associated P. multocida isolates are of limited diversity. A multilocus sequence typing (MLST) scheme for P. multocida was used to determine whether the low levels of diversity reported are due to the limited discriminatory power of the typing method u...

  17. The high cost of mutualism: effects of four species of East African ant symbionts on their myrmecophyte host tree. (United States)

    Stanton, Maureen L; Palmer, Todd M


    Three recent meta-analyses of protective plant-ant mutualisms report a surprisingly weak relationship between herbivore protection and measured demographic benefits to ant-plants, suggesting high tolerance for herbivory, substantial costs of ant-mediated defense, and/or benefits that are realized episodically rather than continuously. Experimental manipulations of protective ant-plant associations typically last for less than a year, yet virtually all specialized myrmecophytes are long-lived perennials for which the costs and benefits of maintaining ant symbionts could accrue at different rates over the host's lifetime. To complement long-term monitoring studies, we experimentally excluded each of four ant symbionts from their long-lived myrmecophyte host trees (Acacia drepanolobium) for 4.5 years. Ant species varied in their effectiveness against herbivores and in their effects on intermediate-term growth and reproduction, but the level of herbivore protection provided was a poor predictor of the net impact they had on host trees. Removal of the three Crematogaster species resulted in cumulative gains in host tree growth and/or reproduction over the course of the experiment, despite the fact that two of those species significantly reduce chronic herbivore damage. In contrast, although T. penzigi is a relatively poor defender, the low cost of maintaining this ant symbiont apparently eliminated negative impacts on overall tree growth and reproduction, resulting in enhanced allocation to new branch growth by the final census. Acacia drepanolobium is evidently highly tolerant of herbivory by insects and small browsers, and the costs of maintaining Crematogaster colonies exceeded the benefits received during the study. No experimental trees were killed by elephants, but elephant damage was uniquely associated with reduced tree growth, and at least one ant species (C. mimosae) strongly deterred elephant browsing. We hypothesize that rare but catastrophic damage by

  18. Selection on body size and sexual size dimorphism differs between host species in a seed-feeding beetle. (United States)

    Fox, C W; Czesak, M E


    Sexual size dimorphism varies substantially among populations and species but we have little understanding of the sources of selection generating this variation. We used path analysis to study how oviposition host affects selection on body size in a seed-feeding beetle (Stator limbatus) in which males contribute large ejaculates (nuptial gifts) to females. Females use nutrients in these ejaculates for egg production. Male body size, which affects ejaculate size, affects female fecundity and is thus under fecundity selection similar in magnitude to the fecundity selection on female body size. We show that when eggs are laid on a host on which larval mortality is low (seeds of Acacia greggii) fecundity predicts fitness very well and fecundity selection is the major source of selection on both male and female adult size. In contrast, when eggs are laid on a host on which larval mortality is high (seeds of Parkinsonia florida) fecundity poorly predicts fitness such that fecundity selection is relaxed on both male and female size. However, because egg size affects larval mortality on this poor host (P. florida) there is selection on female size via the female size --> egg size --> fitness path; this selection via egg size offsets the reduction in fecundity selection on female, but not male, body size. Thus, differences in host suitability (due to differences in larval mortality) affect the relative importance of two sources of selection on adult body size; fecundity selection on both male and female body size is lower on the poor quality host (P. florida) relative to the high quality host (A. greggii) whereas selection on female body size via effects of egg size on offspring survival (body size --> egg size --> fitness) is greater on the poor quality host relative to the high quality host. Because selection via the egg size path affects only females the difference in larval survival between hosts shifts the relative magnitude of selection on female vs. male size

  19. Three new species of Baeoentedon Girault (Hymenoptera: Eulophidae) from China, with the first record of whitefly host association (Hemiptera: Aleyrodidae). (United States)

    Wang, Zhu-Hong; Huang, Jian; Polaszek, Andrew


    Three new species of Baeoentedon Girault (Hymenoptera: Eulophidae) are described from China, Baeoentedon balios Wang, Huang & Polaszek sp. nov., Baeoentedon bouceki Wang, Huang & Polaszek sp. nov. and Baeoentedon virgatus Wang, Huang & Polaszek sp. nov. Both female and male of Baeoentedon balios were reared from the whitefly Pealius spina (Singh) (Hemiptera: Aleyrodidae) on the bodhi tree Ficus religiosa L. (Urticales: Moraceae). The male and the whitefly host association of Baeoentedon are recorded for the first time. A key is also provided to females of the world species of the genus.

  20. Influence of host tree species on isolation and communities of mycorrhizal and endophytic fungi from roots of a tropical epiphytic orchid, Dendrobium sinense (Orchidaceae). (United States)

    Wang, Xiaoming; Li, Yijia; Song, Xiqiang; Meng, Qianwan; Zhu, Jie; Zhao, Ying; Yu, Wengang


    Most studies on the host preference of orchids have focused on the association between orchids and host characteristics, but little is known about the differences of mycorrhizal and endophytic fungal communities in epiphytic orchids growing on different host tree species. We selected Dendrobium sinense, a tropical epiphytic orchid, to determine if fungal endophytes from the roots of D. sinense were preferentially correlated with host tree species. Fifty-six fungal operational taxonomic units (OTUs) from 36 host trees were identified. The results indicated that the species richness and diversity of mycorrhizal and endophytic fungal communities isolated from D. sinense roots were strongly influenced by host tree species. Both species richness and diversity indices showed that D. sinense roots on Syzygium buxifolium harbored the most diverse and abundant endophytic fungi. Species of Tulasnellaceae were dominant on S. buxifolium and Rhododendron moulmainense but infrequent on Cyclobalanopsis disciformis and Podocarpus neriifolius. Our results provide evidence for distinct mycorrhizal and endophytic fungal communities on different host tree species. Further research focusing on fungi-orchid-host preference could be conducted to increase our understanding for the in situ conservation of epiphytic orchids.

  1. A New Clade of Insect-Specific Flaviviruses from Australian Anopheles Mosquitoes Displays Species-Specific Host Restriction. (United States)

    Colmant, Agathe M G; Hobson-Peters, Jody; Bielefeldt-Ohmann, Helle; van den Hurk, Andrew F; Hall-Mendelin, Sonja; Chow, Weng Kong; Johansen, Cheryl A; Fros, Jelke; Simmonds, Peter; Watterson, Daniel; Cazier, Chris; Etebari, Kayvan; Asgari, Sassan; Schulz, Benjamin L; Beebe, Nigel; Vet, Laura J; Piyasena, Thisun B H; Nguyen, Hong-Duyen; Barnard, Ross T; Hall, Roy A


    Flaviviruses are arthropod-borne viruses found worldwide and are responsible for significant human and veterinary diseases, including dengue, Zika, and West Nile fever. Some flaviviruses are insect specific and replicate only in mosquitoes. We report a genetically divergent group of insect-specific flaviviruses from Anopheles mosquitoes that do not replicate in arthropod cell lines or heterologous Anopheles species, exhibiting unprecedented specialization for their host species. Determination of the complete sequences of the RNA genomes of three of these viruses, Karumba virus (KRBV), Haslams Creek virus, and Mac Peak virus (McPV), that are found in high prevalence in some Anopheles mosquito populations and detection of virus-specific proteins, replicative double-stranded RNA, and small interfering RNA responses in the host mosquito species provided strong evidence of a functional replicating virus in the mosquito midgut. Analysis of nucleotide composition in the KRBV and McPV sequences also revealed a pattern consistent with the virus evolving to replicate only in insects. These findings represent a significant advance in our knowledge of mosquito-borne flavivirus ecology, host restriction, and evolution. IMPORTANCE Flaviviruses like dengue, Zika, or West Nile virus infect millions of people each year and are transmitted to humans via infected-mosquito bites. A subset of flaviviruses can only replicate in the mosquito host, and recent studies have shown that some can interfere with pathogenic flaviviruses in mosquitoes and limit the replication and transmission of the latter. The insect-specific flaviviruses (ISFs) reported here form a new Anopheles mosquito-associated clade separate from the Aedes- and Culex-associated ISF clades. The identification of distinct clades for each mosquito genus provides new insights into the evolution and ecology of flaviviruses. One of these viruses was shown to replicate in the midgut of the mosquito host and exhibit the most

  2. Virulent Burkholderia species mimic host actin polymerases to drive actin-based motility (United States)

    Benanti, Erin L.; Nguyen, Catherine M.; Welch, Matthew D.


    Summary Burkholderia pseudomallei and B. mallei are bacterial pathogens that cause melioidosis and glanders, while their close relative B. thailandensis is nonpathogenic. All use the trimeric autotransporter BimA to facilitate actin-based motility, host cell fusion and dissemination. Here, we show that BimA orthologs mimic different host actin-polymerizing proteins. B. thailandensis BimA activates the host Arp2/3 complex. In contrast, B. pseudomallei and B. mallei BimA mimic host Ena/VASP actin polymerases in their ability to nucleate, elongate and bundle filaments by associating with barbed ends, as well as in their use of WH2 motifs and oligomerization for activity. Mechanistic differences among BimA orthologs resulted in distinct actin filament organization and motility parameters, which affected the efficiency of cell fusion during infection. Our results identify bacterial Ena/VASP mimics and reveal that pathogens imitate the full spectrum of host actin-polymerizing pathways, suggesting that mimicry of different polymerization mechanisms influences key parameters of infection. PMID:25860613

  3. Neutrophil elastase causes tissue damage that decreases host tolerance to lung infection with burkholderia species.

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    Manoranjan Sahoo


    Full Text Available Two distinct defense strategies can protect the host from infection: resistance is the ability to destroy the infectious agent, and tolerance is the ability to withstand infection by minimizing the negative impact it has on the host's health without directly affecting pathogen burden. Burkholderia pseudomallei is a Gram-negative bacterium that infects macrophages and causes melioidosis. We have recently shown that inflammasome-triggered pyroptosis and IL-18 are equally important for resistance to B. pseudomallei, whereas IL-1β is deleterious. Here we show that the detrimental role of IL-1β during infection with B. pseudomallei (and closely related B. thailandensis is due to excessive recruitment of neutrophils to the lung and consequent tissue damage. Mice deficient in the potentially damaging enzyme neutrophil elastase were less susceptible than the wild type C57BL/6J mice to infection, although the bacterial burdens in organs and the extent of inflammation were comparable between C57BL/6J and elastase-deficient mice. In contrast, lung tissue damage and vascular leakage were drastically reduced in elastase-deficient mice compared to controls. Bradykinin levels were higher in C57BL/6 than in elastase-deficient mice; administration of a bradykinin antagonist protected mice from infection, suggesting that increased vascular permeability mediated by bradykinin is one of the mechanisms through which elastase decreases host tolerance to melioidosis. Collectively, these results demonstrate that absence of neutrophil elastase increases host tolerance, rather than resistance, to infection by minimizing host tissue damage.

  4. Fish population studies using parasites from the Southeastern Pacific Ocean: considering host population changes and species body size as sources of variability of parasite communities. (United States)

    George-Nascimento, Mario; Oliva, Marcelo


    Research using parasites in fish population studies in the South Eastern Pacific (SEP) is summarized. There are 27 such studies (snapshots mainly) in single host species sampled at different geographic localities and at somewhat similar times. They have been devoted mainly to economically important species, though others on coastal and intertidal fish or on less- or non-commercial species provide insights on scales of temporal and spatial variation of parasite infracommunities. Later, we assess whether the probability of harbouring parasites depends on the host species body size. Our results indicate that a stronger tool for fish population studies may be developed under regular (long term) scrutiny of parasite communities, especially of small fish host species, due to their larger variability in richness, abundance and total biomass, than in large fish species. Finally, it might also be necessary to consider the effects of fishing on parasite communities as well as the natural oscillations (coupled or not) of host and parasite populations.

  5. Isolation of bacteriophage host strains of Bacteroides species suitable for tracking sources of animal faecal pollution in water. (United States)

    Gómez-Doñate, Marta; Payán, Andrey; Cortés, Ivania; Blanch, Anicet R; Lucena, Francisco; Jofre, Juan; Muniesa, Maite


    Microbial source tracking (MST) methods allow the identification of specific faecal sources. The aim is to detect the sources of faecal pollution in a water body to allow targeted, efficient and cost-effective remediation efforts in the catchment. Bacteriophages infecting selected host strains of Bacteroides species are used as markers to track faecal contaminants in water. By using a suitable Bacteroides host from a given faecal origin, it is possible to specifically detect bacteriophages of this faecal origin. It can thus be used to detect specific phages of Bacteroides for MST. With this objective, we isolated several Bacteroides strains from pig, cow and poultry faeces by applying a previously optimized methodology used to isolate the host strains from humans. The isolated strains belonged to Bacteroides fragilis and Bacteroides thetaiotaomicron. These strains, like most Bacteroides species, detected phages of the Siphoviridae morphology. Using the newly isolated host strains for phage enumeration in a range of samples, we showed that these detect phages in faecal sources that coincide with their own origin (70-100% of the samples), and show no detection or very low percentages of detection of phages from other animal origins (from 0 to 20% of the samples). Only strains isolated from pig wastewater detected phages in 50% of human sewage samples. Nevertheless, those strains detecting phages from faecal origins other than their own detected fewer phages (2-3 log₁₀ pfu·100 ml⁻¹) than the phages detected by the specific strain of the same origin. On the basis of our results, we propose that faecal source tracking with phages infecting specific Bacteroides host strains is a useful method for MST. In addition, the method presented here is feasible in laboratories equipped with only basic microbiological equipment, it is more rapid and cost-effective than other procedures and it does not require highly qualified staff. © 2011 Society for Applied Microbiology

  6. Ixodes ricinus ticks are reservoir hosts for Rickettsia helvetica and potentially carry flea-borne Rickettsia species

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    Gaasenbeek Cor


    Full Text Available Abstract Background Hard ticks have been identified as important vectors of rickettsiae causing the spotted fever syndrome. Tick-borne rickettsiae are considered to be emerging, but only limited data are available about their presence in Western Europe, their natural life cycle and their reservoir hosts. Ixodes ricinus, the most prevalent tick species, were collected and tested from different vegetation types and from potential reservoir hosts. In one biotope area, the annual and seasonal variability of rickettsiae infections of the different tick stages were determined for 9 years. Results The DNA of the human pathogen R. conorii as well as R. helvetica, R. sp. IRS and R. bellii-like were found. Unexpectedly, the DNA of the highly pathogenic R. typhi and R. prowazekii and 4 other uncharacterized Rickettsia spp. related to the typhus group were also detected in I. ricinus. The presence of R. helvetica in fleas isolated from small rodents supported our hypothesis that cross-infection can occur under natural conditions, since R. typhi/prowazekii and R. helvetica as well as their vectors share rodents as reservoir hosts. In one biotope, the infection rate with R. helvetica was ~66% for 9 years, and was comparable between larvae, nymphs, and adults. Larvae caught by flagging generally have not yet taken a blood meal from a vertebrate host. The simplest explanation for the comparable prevalence of R. helvetica between the defined tick stages is, that R. helvetica is vertically transmitted through the next generation with high efficiency. The DNA of R. helvetica was also present in whole blood from mice, deer and wild boar. Conclusion Besides R. helvetica, unexpected rickettsiae are found in I. ricinus ticks. We propose that I. ricinus is a major reservoir host for R. helvetica, and that vertebrate hosts play important roles in the further geographical dispersion of rickettsiae.

  7. Species Diversity, Abundance, and Host Preferences of Mosquitoes (Diptera: Culicidae) in Two Different Ecotypes of Madagascar With Recent RVFV Transmission. (United States)

    Jean Jose Nepomichene, Thiery Nirina; Elissa, Nohal; Cardinale, Eric; Boyer, Sebastien


    Mosquito diversity and abundance were examined in six Madagascan villages in either arid (Toliary II district) or humid (Mampikony district) ecotypes, each with a history of Rift Valley fever virus transmission. Centers for Disease Control and Prevention light traps without CO2 (LT) placed near ruminant parks and animal-baited net trap (NT) baited with either zebu or sheep/goat were used to sample mosquitoes, on two occasions between March 2011 and October 2011. Culex tritaeniorhynchus (Giles) was the most abundant species, followed by Culex antennatus (Becker) and Anopheles squamosus/cydippis (Theobald/de Meillon). These three species comprised more than half of all mosquitoes collected. The NT captured more mosquitoes in diversity and in abundance than the LT, and also caught more individuals of each species, except for An. squamosus/cydippis. Highest diversity and abundance were observed in the humid and warm district of Mampikony. No host preference was highlighted, except for Cx. tritaeniorhynchus presenting a blood preference for zebu baits. The description of species diversity, abundance, and host preference described herein can inform the development of control measures to reduce the risk of mosquito-borne diseases in Madagascar.

  8. Definitive hosts of a fatal Versteria species (Cestoda: Taeniidae) in North America (United States)

    We previously reported fatal metacestode infection in a captive orangutan (Pongo pygmaeus) with a novel taeniid tapeworm, Versteria sp. Data from ermine (Mustela erminea) and mink (Neovison vison) implicate mustelids as definitive North America hosts and expand known Versteria diversity. The orangu...

  9. A comparative genomic analysis of putative pathogenicity genes in the host-specific sibling species Colletotrichum graminicola and Colletotrichum sublineola. (United States)

    Buiate, E A S; Xavier, K V; Moore, N; Torres, M F; Farman, M L; Schardl, C L; Vaillancourt, L J


    Colletotrichum graminicola and C. sublineola cause anthracnose leaf and stalk diseases of maize and sorghum, respectively. In spite of their close evolutionary relationship, the two species are completely host-specific. Host specificity is often attributed to pathogen virulence factors, including specialized secondary metabolites (SSM), and small-secreted protein (SSP) effectors. Genes relevant to these categories were manually annotated in two co-occurring, contemporaneous strains of C. graminicola and C. sublineola. A comparative genomic and phylogenetic analysis was performed to address the evolutionary relationships among these and other divergent gene families in the two strains. Inoculation of maize with C. sublineola, or of sorghum with C. graminicola, resulted in rapid plant cell death at, or just after, the point of penetration. The two fungal genomes were very similar. More than 50% of the assemblies could be directly aligned, and more than 80% of the gene models were syntenous. More than 90% of the predicted proteins had orthologs in both species. Genes lacking orthologs in the other species (non-conserved genes) included many predicted to encode SSM-associated proteins and SSPs. Other common groups of non-conserved proteins included transporters, transcription factors, and CAZymes. Only 32 SSP genes appeared to be specific to C. graminicola, and 21 to C. sublineola. None of the SSM-associated genes were lineage-specific. Two different strains of C. graminicola, and three strains of C. sublineola, differed in no more than 1% percent of gene sequences from one another. Efficient non-host recognition of C. sublineola by maize, and of C. graminicola by sorghum, was observed in epidermal cells as a rapid deployment of visible resistance responses and plant cell death. Numerous non-conserved SSP and SSM-associated predicted proteins that could play a role in this non-host recognition were identified. Additional categories of genes that were also highly

  10. Genome-Wide Comparison of Magnaporthe Species Reveals a Host-Specific Pattern of Secretory Proteins and Transposable Elements (United States)

    Gowda, Malali


    Blast disease caused by the Magnaporthe species is a major factor affecting the productivity of rice, wheat and millets. This study was aimed at generating genomic information for rice and non-rice Magnaporthe isolates to understand the extent of genetic variation. We have sequenced the whole genome of the Magnaporthe isolates, infecting rice (leaf and neck), finger millet (leaf and neck), foxtail millet (leaf) and buffel grass (leaf). Rice and finger millet isolates infecting both leaf and neck tissues were sequenced, since the damage and yield loss caused due to neck blast is much higher as compared to leaf blast. The genome-wide comparison was carried out to study the variability in gene content, candidate effectors, repeat element distribution, genes involved in carbohydrate metabolism and SNPs. The analysis of repeat element footprints revealed some genes such as naringenin, 2-oxoglutarate 3-dioxygenase being targeted by Pot2 and Occan, in isolates from different host species. Some repeat insertions were host-specific while other insertions were randomly shared between isolates. The distributions of repeat elements, secretory proteins, CAZymes and SNPs showed significant variation across host-specific lineages of Magnaporthe indicating an independent genome evolution orchestrated by multiple genomic factors. PMID:27658241

  11. Diversity of the skin microbiota of fishes: evidence for host species specificity. (United States)

    Larsen, Andrea; Tao, Zhen; Bullard, Stephen A; Arias, Covadonga R


    Skin microbiota of Gulf of Mexico fishes were investigated by ribosomal internal spacer analysis (RISA) and 16S rRNA gene sequencing. A total of 102 fish specimens representing six species (Mugil cephalus, Lutjanus campechanus, Cynoscion nebulosus, Cynoscion arenarius, Micropogonias undulatus, and Lagodon rhomboides) were sampled at regular intervals throughout a year. The skin microbiota from each individual fish was analyzed by RISA and produced complex profiles with 23 bands on average. Similarities between RISA profiles ranged from 97.5% to 4.0%. At 70% similarity, 11 clusters were defined, each grouping individuals from the same fish species. Multidimensional scaling and analysis of similarity correlated the RISA-defined clusters with geographic locality, date, and fish species. Global R values indicated that fish species was the most indicative variable for group separation. Analysis of 16S rRNA gene sequences (from pooled samples of 10 individual fish for each fish species) showed that the Proteobacteria was the predominant phylum in skin microbiota, followed by the Firmicutes and the Actinobacteria. The distribution and abundance of bacterial sequences were different among all species analyzed. Aeribacillus was found in all fish species representing 19% of all clones sequenced, while some genera were fish species-specific (Neorickettsia in M. cephalus and Microbacterium in L. campechanus). Our data provide evidence for the existence of specific skin microbiota associated with particular fish species. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  12. Tree species as hosts for arbuscular mycorrhizal and dark septate endophyte fungi

    Institute of Scientific and Technical Information of China (English)

    E.Uma; K.Sathiyadash; J.Loganathan; T.Muthukumar


    A survey of 35 tree species (belonging to 28 genera in 19families) in Aliyar,South India was carried out to ascertain their arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal status.All the tree species examined had AM association.AM and DSE colonization is reported for the first time in 20 and 14 species respectively.Cooccurrence of AM and DSE was observed in 14 (40%) tree species.The extent of DSE colonization was inversely related to the extent of AM fungal colonization.Six tree species had Arum-type,18 had intermediatetype and 1l had typical Paris-type AM morphology.AM fungal spore morphotypes belonging to 11 species in two genera were isolated from the rhizosphere soil.AM fungal spore numbers were not related to the extent of AM colonization and Glomus dominated spore diversity.AM association individually and along with DSE were found respectively in the 63% and 44% of the economically important tree species.The occurrence of AM and DSE fungal association in economically important indigenous tree species indicates the possibility of exploiting this association in future conservation programmes of these species.

  13. Molecular Techniques for the Detection and Differentiation of Host and Parasitoid Species and the Implications for Fruit Fly Management. (United States)

    Jenkins, Cheryl; Chapman, Toni A; Micallef, Jessica L; Reynolds, Olivia L


    Parasitoid detection and identification is a necessary step in the development and implementation of fruit fly biological control strategies employing parasitoid augmentive release. In recent years, DNA-based methods have been used to identify natural enemies of pest species where morphological differentiation is problematic. Molecular techniques also offer a considerable advantage over traditional morphological methods of fruit fly and parasitoid discrimination as well as within-host parasitoid identification, which currently relies on dissection of immature parasitoids from the host, or lengthy and labour-intensive rearing methods. Here we review recent research focusing on the use of molecular strategies for fruit fly and parasitoid detection and differentiation and discuss the implications of these studies on fruit fly management.

  14. The Glycoproteins of All Filovirus Species Use the Same Host Factors for Entry into Bat and Human Cells but Entry Efficiency Is Species Dependent.

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    Markus Hoffmann

    Full Text Available Ebola and marburgviruses, members of the family Filoviridae, can cause severe hemorrhagic fever in humans. The ongoing Ebola virus (EBOV disease epidemic in Western Africa claimed more than 11,300 lives and was associated with secondary cases outside Africa, demonstrating that filoviruses pose a global health threat. Bats constitute an important natural reservoir of filoviruses, including viruses of the recently identified Cuevavirus genus within the Filoviridae family. However, the interactions of filoviruses with bat cells are incompletely understood. Here, we investigated whether filoviruses employ different strategies to enter human and bat cells. For this, we examined host cell entry driven by glycoproteins (GP from all filovirus species into cell lines of human and fruit bat origin. We show that all GPs were able to mediate entry into human and most fruit bat cell lines with roughly comparable efficiency. In contrast, the efficiency of entry into the cell line EidNi/41 derived from a straw-colored fruit bat varied markedly between the GPs of different filovirus species. Furthermore, inhibition studies demonstrated that filoviruses employ the same host cell factors for entry into human, non-human primate and fruit bat cell lines, including cysteine proteases, two pore channels and NPC1 (Niemann-Pick C1 molecule. Finally, processing of GP by furin and the presence of the mucin-like domain in GP were dispensable for entry into both human and bat cell lines. Collectively, these results show that filoviruses rely on the same host cell factors for entry into human and fruit bat cells, although the efficiency of the usage of these factors might differ between filovirus species.

  15. Cross-species Virus-host Protein-Protein Interactions Inhibiting Innate Immunity (United States)


    SUBJECTTERMS viral pathogen, zoonotic, arenavirus, host tropism, protein - protein interactions, RIG-I, Z protein , CARD domain, MAVS 16. SECURITY...individually subcloned into Checkmate M2H System (Promega) bait and prey reporter plasmids. The genes encoding the viral Z proteins were synthesized... viral proteins were calculated with PhyML. While several residue positions are highly conserved across Z proteins (Figure 8), significant sequence

  16. Possible Influence of MLP Regulators in Foliage of Host Species on Invasion of Phyllophagous Insects

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    Vasiliy I. Ponomarev


    Full Text Available On the northern border of the Gypsy moth area (Lymantria dispar L., 1758, caterpillars are reorient to exogenous regulators of membrane lipid peroxidation in connection with repeated cold periods during feeding. In case of an introduction of host plants with high contents of exogenous regulators of MLP (e.g. Fe2+ in foliage in these areas that may affect diapause duration, the boundaries of spreading and intensity of outbreaks may change.

  17. Host specificity and genealogy of the louse Polyplax serrata on field mice, Apodemus species: a case of parasite duplication or colonisation? (United States)

    Stefka, Jan; Hypsa, Václav


    The genealogy, population structure and population dynamics of the sucking louse Polyplax serrata were analysed across four host species of the genus Apodemus. An analysis of 126 sequences of cytochrome c oxidase subunit I using phylogenetic approaches and haplotype networking revealed a clear structure of European samples, forming three distinct and genetically distant clades with different host specificities. Although a clear connection was detected between the host and parasite genealogies/phylogenies, a uniform pattern of co-speciation was not found. For example, a dramatic shift in the degree of host specificity was demonstrated for two related louse lineages living in sympatry and sharing one of their host species. While one of the louse lineages frequently parasitised two different host taxa (Apodemus sylvaticus and Apodemus flavicollis), the other louse lineage was strictly specific to A. flavicollis. The estimate of divergence time between the two louse lineages indicates that they may have arisen due to parasite duplication on A. flavicollis.

  18. Characterization of the host response to pichinde virus infection in the Syrian golden hamster by species-specific kinome analysis. (United States)

    Falcinelli, Shane; Gowen, Brian B; Trost, Brett; Napper, Scott; Kusalik, Anthony; Johnson, Reed F; Safronetz, David; Prescott, Joseph; Wahl-Jensen, Victoria; Jahrling, Peter B; Kindrachuk, Jason


    The Syrian golden hamster has been increasingly used to study viral hemorrhagic fever (VHF) pathogenesis and countermeasure efficacy. As VHFs are a global health concern, well-characterized animal models are essential for both the development of therapeutics and vaccines as well as for increasing our understanding of the molecular events that underlie viral pathogenesis. However, the paucity of reagents or platforms that are available for studying hamsters at a molecular level limits the ability to extract biological information from this important animal model. As such, there is a need to develop platforms/technologies for characterizing host responses of hamsters at a molecular level. To this end, we developed hamster-specific kinome peptide arrays to characterize the molecular host response of the Syrian golden hamster. After validating the functionality of the arrays using immune agonists of defined signaling mechanisms (lipopolysaccharide (LPS) and tumor necrosis factor (TNF)-α), we characterized the host response in a hamster model of VHF based on Pichinde virus (PICV(1)) infection by performing temporal kinome analysis of lung tissue. Our analysis revealed key roles for vascular endothelial growth factor (VEGF), interleukin (IL) responses, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling, and Toll-like receptor (TLR) signaling in the response to PICV infection. These findings were validated through phosphorylation-specific Western blot analysis. Overall, we have demonstrated that hamster-specific kinome arrays are a robust tool for characterizing the species-specific molecular host response in a VHF model. Further, our results provide key insights into the hamster host response to PICV infection and will inform future studies with high-consequence VHF pathogens.

  19. Crustose coralline algal species host distinct bacterial assemblages on their surfaces. (United States)

    Sneed, Jennifer M; Ritson-Williams, Raphael; Paul, Valerie J


    Crustose coralline algae (CCA) are important components of many marine ecosystems. They aid in reef accretion and stabilization, create habitat for other organisms, contribute to carbon sequestration and are important settlement substrata for a number of marine invertebrates. Despite their ecological importance, little is known about the bacterial communities associated with CCA or whether differences in bacterial assemblages may have ecological implications. This study examined the bacterial communities on four different species of CCA collected in Belize using bacterial tag-encoded FLX amplicon pyrosequencing of the V1-V3 region of the 16S rDNA. CCA were dominated by Alphaproteobacteria, Gammaproteobacteria and Actinomycetes. At the operational taxonomic unit (OTU) level, each CCA species had a unique bacterial community that was significantly different from all other CCA species. Hydrolithon boergesenii and Titanoderma prototypum, CCA species that facilitate larval settlement in multiple corals, had higher abundances of OTUs related to bacteria that inhibit the growth and/or biofilm formation of coral pathogens. Fewer coral larvae settle on the surfaces of Paragoniolithon solubile and Porolithon pachydermum. These CCA species had higher abundances of OTUs related to known coral pathogens and cyanobacteria. Coral larvae may be able to use the observed differences in bacterial community composition on CCA species to assess the suitability of these substrata for settlement and selectively settle on CCA species that contain beneficial bacteria.

  20. Patterns in root traits of woody species hosting arbuscular and ectomycorrhizas: implications for the evolution of belowground strategies. (United States)

    Comas, Louise H; Callahan, Hilary S; Midford, Peter E


    Root traits vary enormously among plant species but we have little understanding of how this variation affects their functioning. Of central interest is how root traits are related to plant resource acquisition strategies from soil. We examined root traits of 33 woody species from northeastern US forests that form two of the most common types of mutualisms with fungi, arbuscular mycorrhizas (AM) and ectomycorrhizas (EM). We examined root trait distribution with respect to plant phylogeny, quantifying the phylogenetic signal (K statistic) in fine root morphology and architecture, and used phylogenetically independent contrasts (PICs) to test whether taxa forming different mycorrhizal associations had different root traits. We found a pattern of species forming roots with thinner diameters as species diversified across time. Given moderate phylogenetic signals (K = 0.44-0.68), we used PICs to examine traits variation among taxa forming AM or EM, revealing that hosts of AM were associated with lower branching intensity (r PIC = -0.77) and thicker root diameter (r PIC = -0.41). Because EM evolved relatively more recently and intermittently across plant phylogenies, significant differences in root traits and colonization between plants forming AM and EM imply linkages between the evolution of these biotic interactions and root traits and suggest a history of selection pressures, with trade-offs for supporting different types of associations. Finally, across plant hosts of both EM and AM, species with thinner root diameters and longer specific root length (SRL) had less colonization (r PIC = 0.85, -0.87), suggesting constraints on colonization linked to the evolution of root morphology.

  1. Host heterogeneity influences the impact of a non-native disease invasion on populations of a foundation tree species (United States)

    Jules, Erik S.; Carroll, Allyson L.; Garcia, Andrea M.; Steenbock, Christopher M.; Kauffman, Matthew J.


    Invasive pathogens are becoming increasingly important in forested ecosystems, yet they are often difficult to study because of their rapid transmission. The rate and extent of pathogen spread are thought to be partially controlled by variation in host characteristics, such as when host size and location influence susceptibility. Few host-pathogen systems, however, have been used to test this prediction. We used Port Orford cedar (Chamaecyparis lawsoniana), a foundation tree species in riparian areas of California and Oregon (USA), and the invasive oomycete Phytophthora lateralis to assess pathogen impacts and the role of host characteristics on invasion. Across three streams that had been infected for 13–18 years by P. lateralis, we mapped 2241 trees and determined whether they had been infected using dendrochronology. The infection probability of trees was governed by host size (diameter at breast height [DBH]) and geomorphic position (e.g., active channel, stream bank, floodplain, etc.) similarly across streams. For instance, only 23% of trees DBH were infected, while 69% of trees ≥20 cm DBH were infected. Presumably, because spores of P. lateralis are transported downstream in water, they are more likely to encounter well-developed root systems of larger trees. Also because of this water-transport of spores, differences in infection probability were found across the geomorphic positions: 59% of cedar in the active channel and the stream bank (combined) were infected, while 23% of trees found on higher geomorphic types were infected. Overall, 32% of cedar had been infected across the three streams. However, 63% of the total cedar basal area had been killed, because the greatest number of trees, and the largest trees, were found in the most susceptible positions. In the active channel and stream bank, 91% of the basal area was infected, while 46% was infected across higher geomorphic positions. The invasion of Port Orford cedar populations by

  2. [1st cases of adiaspiromycosis observed in small mammals in Turkey. 3 new host species]. (United States)

    Boisseau-Lebreuil, M T; Orhan, V


    The authors examine the lungs of 193 small mammals caught in different places in West Turkey and belonging to 11 different species. Six species have one or many adiaspores in their lungs. Those are Microtus arvalis, Apodemus flavicollis and A. sylvaticus already found parasited by Chrysosporium parvum in many countries particularly France. These are M. guentheri, Pitymys majori and A. mystacinus which have never been mentioned before this day having adiaspiromycosis.

  3. Evolution of endogenous retroviruses in the Suidae: evidence for different viral subpopulations in African and Eurasian host species

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    Charleston Michael


    Full Text Available Abstract Background Porcine endogenous retroviruses (PERVs represent remnants of an exogenous form that have become integrated in the domestic pig (Sus scrofa genome. Although they are usually inactive, the capacity of γ1 ERVs to infect human cells in vitro has raised concerns about xenotransplantation because the viruses could cross the species barrier to humans. Here we have analyzed the evolution of γ1 ERVs in ten species of Suidae (suids, pigs and hogs from Eurasia and Africa using DNA sequences for their coding domains (gag, pro/pol and env genes. For comparison with γ1 PERVs, we have also analysed γ2 ERVs which in domestic pigs are known to be inactive and do not pose a risk to xenotransplantation. Results Phylogenetic analysis using Bayesian inference showed that γ1 and γ2 ERVs have distinctive evolutionary histories. Firstly, two different viral lineages of γ1 ERVs were found and a coevolutionary analysis demonstrated that they correspond broadly to their host phylogeny, one of Eurasian and another of African species, and show no evidence of horizontal transmission. γ2 ERVs, however, show a bush-like evolution, suggesting a rapid viral radiation from a single common ancestor with no correspondence between host and viral evolutionary trees. Furthermore, though γ1 ERV env genes do not possess frequent stop codons, γ2 env genes do. To understand whether γ1 suid ERVs may be still replicating, we have also evaluated their likely mechanism of proliferation by statistically testing internal to terminal branches using nonsynonymous versus synonymous substitution ratios. Our results suggest that γ1 ERVs are increasing in copy number by reinfection, which requires the translocation of the virus from one cell to another. Conclusions Evidence of at least two viral subpopulations was observed in γ1 ERVs from Eurasian and African host species. These results should be taken into account in xenotransplantation since γ1 ERVs appear to be

  4. Comparative phylogeography of two monogenean species (Mazocraeidae) on the host of chub mackerel, Scomber japonicus, along the coast of China. (United States)

    Yan, Shuai; Wang, Ming; Yang, Chao-Pin; Zhi, Ting-Ting; Brown, Christopher L; Yang, Ting-Bao


    In the present paper, the phylogeographies of two monogenean species, Pseudokuhnia minor and Kuhnia scombri, on the same species of host, Scomber japonicus, were studied. Fragments of the mitochondrial cytochrome c oxidase subunit 1 gene were sequenced for 264 individuals of P. minor and 224 individuals of K. scombri collected from 10 localities along the coast of China. Genetic diversity of K. scombri was higher than that of P. minor, which may imply that P. minor has a lower evolution rate and/or is a younger species. The neighbour-joining (NJ) trees of both parasites were comprised of two clades without association to sample sites, which is the signature of remixing populations following past division. Analyses of molecular variance and pairwise fixation index revealed different genetic structures for the populations of these two closely related species along the coast of China: P. minor without significant genetic structure, while K. scombri has some genetic differentiation. Both neutrality tests and mismatch distribution suggested that the populations of these two species of parasites experienced population expansion in the late Pleistocene era due to the glacial-interglacial cycles induced by climatic oscillations.

  5. Leluthia astigma (Ashmead) (Hymenoptera: Braconidae: Doryctinae) as a parasitoid of Agrilus planipennis Fairmaire (Coleoptera: Buprestidae: Agrilinae), with an assessment of host associations for nearctic species of Leluthia Cameron. (United States)

    Robert R. Kula; Kathleen S. Knight; Joanne Rebbeck; Leah S. Bauer; David L. Cappaert; Kamal J.K. Gandhi


    Published host associations are assessed for Leluthia astigma (Ashmead), Leluthia floridensis Marsh, and Leluthia mexicana Cameron, the three known species of Leluthia Cameron in the Nearctic Region. Leluthia astigma is reported as a parasitoid of Agrilus planipennis...

  6. Tree phyllosphere bacterial communities: exploring the magnitude of intra- and inter-individual variation among host species

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    Isabelle Laforest-Lapointe


    Full Text Available Background The diversity and composition of the microbial community of tree leaves (the phyllosphere varies among trees and host species and along spatial, temporal, and environmental gradients. Phyllosphere community variation within the canopy of an individual tree exists but the importance of this variation relative to among-tree and among-species variation is poorly understood. Sampling techniques employed for phyllosphere studies include picking leaves from one canopy location to mixing randomly selected leaves from throughout the canopy. In this context, our goal was to characterize the relative importance of intra-individual variation in phyllosphere communities across multiple species, and compare this variation to inter-individual and interspecific variation of phyllosphere epiphytic bacterial communities in a natural temperate forest in Quebec, Canada. Methods We targeted five dominant temperate forest tree species including angiosperms and gymnosperms: Acer saccharum, Acer rubrum, Betula papyrifera, Abies balsamea and Picea glauca. For one randomly selected tree of each species, we sampled microbial communities at six distinct canopy locations: bottom-canopy (1–2 m height, the four cardinal points of mid-canopy (2–4 m height, and the top-canopy (4–6 m height. We also collected bottom-canopy leaves from five additional trees from each species. Results Based on an analysis of bacterial community structure measured via Illumina sequencing of the bacterial 16S gene, we demonstrate that 65% of the intra-individual variation in leaf bacterial community structure could be attributed to the effect of inter-individual and inter-specific differences while the effect of canopy location was not significant. In comparison, host species identity explains 47% of inter-individual and inter-specific variation in leaf bacterial community structure followed by individual identity (32% and canopy location (6%. Discussion Our results suggest that

  7. Differential stepwise evolution of SARS coronavirus functional proteins in different host species

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    Tang Xianchun


    Full Text Available Abstract Background SARS coronavirus (SARS-CoV was identified as the etiological agent of SARS, and extensive investigations indicated that it originated from an animal source (probably bats and was recently introduced into the human population via wildlife animals from wet markets in southern China. Previous studies revealed that the spike (S protein of SARS had experienced adaptive evolution, but whether other functional proteins of SARS have undergone adaptive evolution is not known. Results We employed several methods to investigate selective pressure among different SARS-CoV groups representing different epidemic periods and hosts. Our results suggest that most functional proteins of SARS-CoV have experienced a stepwise adaptive evolutionary pathway. Similar to previous studies, the spike protein underwent strong positive selection in the early and middle phases, and became stabilized in the late phase. In addition, the replicase experienced positive selection only in human patients, whereas assembly proteins experienced positive selection mainly in the middle and late phases. No positive selection was found in any proteins of bat SARS-like-CoV. Furthermore, specific amino acid sites that may be the targets of positive selection in each group are identified. Conclusion This extensive evolutionary analysis revealed the stepwise evolution of different functional proteins of SARS-CoVs at different epidemic stages and different hosts. These results support the hypothesis that SARS-CoV originated from bats and that the spill over into civets and humans were more recent events.

  8. Patterns of bacteria-host associations suggest different ecological strategies between two reef building cold-water coral species (United States)

    Meistertzheim, Anne.-Leila; Lartaud, Franck; Arnaud-Haond, Sophie; Kalenitchenko, Dimitri; Bessalam, Manon; Le Bris, Nadine; Galand, Pierre E.


    Cold-water corals (CWC) are main ecosystem engineers of the deep sea, and their reefs constitute hot-spots of biodiversity. However, their ecology remains poorly understood, particularly, the nature of the holobiont formed by corals with their associated bacterial communities. Here, we analyzed Madrepora oculata and Lophelia pertusa samples, collected from one location in a Mediterranean canyon in two different seasons (autumn and spring), in order to test for species specificity and temporal stability of the host-bacteria associations. The 16S rRNA sequencing revealed host-specific patterns of bacterial communities associated with L. pertusa and M. oculata, both in terms of community composition and diversity. All analyzed M. oculata polyps exhibited temporally and spatially similar bacterial communities dominated by haplotypes homologous to the known cnidarians-associated genus Endozoicomonas. In contrast, the bacterial communities associated with L. pertusa varied among polyps from the same colony, as well as among distinct colonies and between seasons. While the resilient consortium formed by M. oculata and its bacterial community fit the definition of holobiont, the versatility of the L. pertusa microbiome suggests that this association is more influenced by the environmental conditions or nutritional status. Our results thus highlight distinct host/microbes association strategies for these two closely related Scleractinians sharing the same habitat, suggesting distinct sensitivity to environmental change.

  9. Ticks (Acarina: Ixodida) infesting five reptile species in Sri Lanka with sixteen new host records. (United States)

    Liyanaarachchi, Dilrukshi R; Rajakaruna, Rupika S; Dikkumbura, Anil W; De Silva, Anslem; Rajapakse, R P V Jayantha


    The first study on ticks on reptiles of Sri Lanka dates back to Seneviratna (1965) who reported ticks from five reptiles. Later studies were either limited to one reptile (Fernando & Fernando 2012), or captive animals in zoos (Fernando & Randeniaya 2009) and household pets (Nathanael et al. 2004). According to the current classification (Guglielmone et al. 2010), all the tick species previously recorded on reptiles belong to five species of Amblyomma: A. clypeolatum Neumann, A. gervaisi (Lucas), A. pattoni (Neumann), A. trimaculatum (Lucas) and A. varanense (Supino). Some of the species listed by Seneviratna (1965) were either synonyms or invalid in respect to the present classification. For example Amblyomma laeve sensu Warburton (1910) is a junior synonym of A. pattoni and A. gervaisii var. lucasi is considered a junior synonym of A. varanense (Guglielmone et al. 2010; D. Apanaskevich pers. comm.).

  10. First Introduction of Two Australian Temnocephalan Species into Africa with an Alien Host: Double Trouble. (United States)

    Tavakol, Sareh; Luus-Powell, Wilmien J; Smit, Willem J; Baker, Chantélle; Hoffman, Andre; Halajian, Ali


    The redclaw crayfish, Cherax quadricarinatus (Decapoda: Parastacidae), is native to Australia but has been introduced to South Africa as a warm-water aquaculture species. In a South African natural waterbody, examined crayfish had high-intensity infections of 3 temnocephalan species on their body surfaces and within the branchial chambers. Temnocephalans were characterized using light and scanning electron microscopy and identified as Craspedella pedum, Diceratocephala boschmai, and Didymorchis sp. This is the first report of the introduction of Australian temnocephalans, C. pedum and Didymorchis sp., to Africa and expands the known distribution of these species beyond their presumptive native range. The present study also documents a naturalized population of C. quadricarinatus from a natural water body in South Africa, comprising a new geographical locality record.

  11. Expression Divergence of Chemosensory Genes between Drosophila sechellia and Its Sibling Species and Its Implications for Host Shift (United States)

    Shiao, Meng-Shin; Chang, Jia-Ming; Fan, Wen-Lang; Lu, Mei-Yeh Jade; Notredame, Cedric; Fang, Shu; Kondo, Rumi; Li, Wen-Hsiung


    Drosophila sechellia relies exclusively on the fruits of Morinda citrifolia, which are toxic to most insects, including its sibling species Drosophila melanogaster and Drosophila simulans. Although several odorant binding protein (Obp) genes and olfactory receptor (Or) genes have been suggested to be associated with the D. sechellia host shift, a broad view of how chemosensory genes have contributed to this shift is still lacking. We therefore studied the transcriptomes of antennae, the main organ responsible for detecting food resource and oviposition, of D. sechellia and its two sibling species. We wanted to know whether gene expression, particularly chemosensory genes, has diverged between D. sechellia and its two sibling species. Using a very stringent definition of differential gene expression, we found a higher percentage of chemosensory genes differentially expressed in the D. sechellia lineage (7.8%) than in the D. simulans lineage (5.4%); for upregulated chemosensory genes, the percentages were 8.8% in D. sechellia and 5.2% in D. simulans. Interestingly, Obp50a exhibited the highest upregulation, an approximately 100-fold increase, and Or85c—previously reported to be a larva-specific gene—showed approximately 20-fold upregulation in D. sechellia. Furthermore, Ir84a (ionotropic receptor 84a), which has been proposed to be associated with male courtship behavior, was significantly upregulated in D. sechellia. We also found expression divergence in most of the chemosensory gene families between D. sechellia and the two sibling species. Our observations suggest that the host shift of D. sechellia was associated with the enrichment of differentially expressed, particularly upregulated, chemosensory genes. PMID:26430061

  12. Quantitative analysis of commensal Escherichia coli populations reveals host-specific enterotypes at the intra-species level. (United States)

    Smati, Mounira; Clermont, Olivier; Bleibtreu, Alexandre; Fourreau, Frédéric; David, Anthony; Daubié, Anne-Sophie; Hignard, Cécile; Loison, Odile; Picard, Bertrand; Denamur, Erick


    The primary habitat of the Escherichia coli species is the gut of warm-blooded vertebrates. The E. coli species is structured into four main phylogenetic groups A, B1, B2, and D. We estimated the relative proportions of these phylogroups in the feces of 137 wild and domesticated animals with various diets living in the Ile de France (Paris) region by real-time PCR. We distinguished three main clusters characterized by a particular abundance of two or more phylogroups within the E. coli animal commensal populations, which we called "enterocolitypes" by analogy with the enterotypes defined in the human gut microbiota at the genus level. These enterocolitypes were characterized by a dominant (>50%) B2, B1, or A phylogroup and were associated with different host species, diets, and habitats: wild and herbivorous species (wild rabbits and deer), domesticated herbivorous species (domesticated rabbits, horses, sheep, and cows), and omnivorous species (boar, pigs, and chickens), respectively. By analyzing retrospectively the data obtained using the same approach from 98 healthy humans living in Ile de France (Smati et al. 2013, Appl. Environ. Microbiol. 79, 5005-5012), we identified a specific human enterocolitype characterized by the dominant and/or exclusive (>90%) presence of phylogroup B2. We then compared B2 strains isolated from animals and humans, and revealed that human and animal strains differ regarding O-type and B2 subgroup. Moreover, two genes, sfa/foc and clbQ, were associated with the exclusive character of strains, observed only in humans. In conclusion, a complex network of interactions exists at several levels (genus and intra-species) within the intestinal microbiota. © 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  13. A Comparison of Fitness Characters of Two Host Plant-Based Congeneric Species of the Banana Aphid, Pentalonia Nigronervosa and P. Caladii (United States)

    Bhadra, Parna; Agarwala, B. K.


    Aphids and other phytophagous insects often show intra-specific variations in relation to host plant utilization. In several instances, intra-species variations lead to host-plant specialization. These are considered to be important source of speciation. In a recent study (Foottit RG et al. 2010. Zootaxa 2358: 25–38) two forms of the banana aphid, Pentalonia nigronervosa f typica Coquerel (Hemiptera: Aphididae) from banana hosts and P. nigronervosa f. caladii van der Goot collected from Zingiberaceae and Araceae respectively were described as separate species, P. nigronervosa Coquerel and P. caladii van der Goot, based on morphological and molecular differences. A study was undertaken to examine the ecological and biological characters in asexual wingless morphs of the two forms of P. nigronervosa sensu lat. using taro (Araceae) and banana (Musaceae) as host plants. The results showed consistent differences between the two forms. In biological characters, the apterous morphs off. caladii from taro host plants were found to be significantly more fecund, showed a higher net reproductive rate, longer reproductive duration, and their adults lived longer than the f. typica aphids from banana host plants. In ecological characters, f. caladii aphids formed bigger colonies and in significantly less time on taro plants in comparison to f. typica aphids which formed smaller colonies in significantly more time on banana plants. Reciprocal transfer of the two forms of P. nigronervosa aphids between their host plant species lowered performance on the transferred host plants. These results confirmed that P. nigronervosa f. typica from banana hosts and P. nigronervosa f. caladii from taro hosts are indeed two different species in relation to host plant utilization and suggested that the observed differences in their fitness characters represented distinct genotypes. PMID:20883136

  14. Opisthorchis viverrini: Implications of the systematics of first intermediate hosts, Bithynia snail species in Thailand and Lao PDR. (United States)

    Kiatsopit, Nadda; Sithithaworn, Paiboon; Saijuntha, Weerachai; Petney, Trevor N; Andrews, Ross H


    Bithynia snails are important hosts of the human liver fluke, Opisthorchis viverrini. Allozyme markers were used to examine genetic variation and the systematics of Bithynia snails from different geographical localities in Thailand and Lao PDR. Our results show that Bithynia siamensis goniomphalos contains two major evolutionary clades with at least nine morphologically similar but genetically distinct "cryptic" species (taxa). Clade A consists of snails from the Chi and the Mun River wetlands, Thailand and clade B consists of snails from the Nam Ngum River wetland, Lao PDR, as well as snails from some localities in the Songkram River wetland, Thailand. There is an association between O. viverrini cryptic taxa with B. s. goniomphalos cryptic taxa within the defined wetlands. Bithynia species are the critical amplifying component of O. viverrini and they control transmission from humans to fish second intermediate hosts. These findings are particularly important for understanding the transmission dynamics of O. viverrini. They are, in addition, a link in the life cycle of O. viverrini which can be used for developing and implementing programs to eliminate and control opisthorchiasis and its associated cholangiocarcinoma.

  15. Temporal changes of symbiont density and host fitness after rifampicin treatment in a whitefly of the Bemisia tabaci species complex. (United States)

    Shan, Hong-Wei; Zhang, Chang-Rong; Yan, Ting-Ting; Tang, Hai-Qin; Wang, Xiao-Wei; Liu, Shu-Sheng; Liu, Yin-Quan


    Microbial symbionts are essential or important partners to phloem-feeding insects. Antibiotics have been used to selectively eliminate symbionts from their host insects and establish host lines with or without certain symbionts for investigating functions of the symbionts. In this study, using the antibiotic rifampicin we attempted to selectively eliminate certain symbionts from a population of the Middle East-Asia Minor 1 whitefly of the Bemisia tabaci species complex, which harbors the primary symbiont "Candidatus Portiera aleyrodidarum" and two secondary symbionts "Candidatus Hamiltonella defensa" and Rickettsia. Neither the primary nor the secondary symbionts were completely depleted in the adults (F0) that fed for 48 h on a diet treated with rifampicin at concentrations of 1-100 μg/mL. However, both the primary and secondary symbionts were nearly completely depleted in the offspring (F1) of the rifampicin-treated adults. Although the F1 adults produced some eggs (F2), most of the eggs failed to hatch and none of them reached the second instar, and consequently the rifampicin-treated whitefly colony vanished at the F2 generation. Interestingly, quantitative polymerase chain reaction assays showed that in the rifampicin-treated whiteflies, the density of the primary symbiont was reduced at an obviously slower pace than the secondary symbionts. Mating experiments between rifampicin-treated and untreated adults demonstrated that the negative effects of rifampicin on host fitness were expressed when the females were treated by the antibiotic, and whether males were treated or not by the antibiotic had little contribution to the negative effects. These observations indicate that with this whitefly population it is not feasible to selectively eliminate the secondary symbionts using rifampicin without affecting the primary symbiont and establish host lines for experimental studies. However, the extinction of the whitefly colony at the second generation after

  16. New species and host plants of Anastrepha (Diptera: Tephritidae) primarily from Peru and Bolivia (United States)

    Twenty-eight new species of Anastrepha are described and illustrated: A. acca (Bolivia, Peru), A. adami (Peru), A. amplidentata (Bolivia, Peru), A. annonae (Peru), A. breviapex (Peru), A. caballeroi (Peru), A. camba (Bolivia, Peru), A. cicra (Bolivia, Peru), A. disjuncta (Peru), A. durantae (Peru), ...

  17. Foot and mouth disease virus in different host species; the effect of vaccination on transmission

    NARCIS (Netherlands)

    Orsel, K.


    Foot and mouth disease (FMD) is a contagious disease, affecting important livestock species like cattle, sheep and pigs. Therefore, FMD is listed as a notifiable disease to the Office International des Epizooties. The outbreaks of FMD in Europe in 2001 triggered the discussion about the use of vacci

  18. Impact of curly top host plants on accumulation, competitiveness, and durability of curtovirus species. (United States)

    Curly top disease, caused by viruses in the genus, Curtovirus, has affected sugarbeet production throughout much of the West for over a century; however, over that period the viruses responsible for causing the disease have changed. The two curly top virus species currently affecting production, Bee...

  19. Genetic uniformity of Echinococcus multilocularis collected from different intermediate host species in Hokkaido, Japan. (United States)

    Okamoto, Munehiro; Oku, Yuzaburo; Kurosawa, Tsutomu; Kamiya, Masao


    DNA from several isolates of Taenia taeniaeformis and Echinococcus multilocularis were digested with restriction enzymes and hybridized with digoxigenated oligonucleotide probe (CAC)5. Within the six wild isolates of Taenia taeniaeformis from Norway rats in Hokkaido, although several bands were common among isolates, fingerprinting patterns were specific to each isolate. In the case of E. multilocularis, regardless of hosts from which each isolate has been isolated, the five isolates collected from Hokkaido, showed the same fingerprinting pattern. These results indicate that there was very little genetic difference among these isolates. Although the fingerprinting pattern of E. multilocularis from St. Lawrence Is. was similar to that of the Hokkaido isolates, some bands were different from those in the Hokkaido isolates. Echinococcus multilocularis in Hokkaido seems to be closely-related genetically to that from St. Lawrence Is.

  20. Fungal host specificity is not a bottleneck for the germination of Pyroleae species (Ericaceae) in a Bavarian forest. (United States)

    Hynson, Nicole A; Weiß, Michael; Preiss, Katja; Gebauer, Gerhard; Treseder, Kathleen K


    Plants that produce dust seeds can recruit fungi to meet their earliest requirements for carbon and other nutrients. This germination strategy, termed initial mycoheterotrophy, has been well investigated among the orchid family, but there are numerous other plant lineages that have independently evolved mycoheterotrophic germination strategies. One of these lineages is the tribe Pyroleae (Ericaceae). While the fungi associated with mature plants in Pyroleae have been fairly well documented, their mycobionts at the germination and seedling stages are largely unknown. Here, we use an in situ seed baiting experiment along with molecular fingerprinting techniques and phylogenetic tests to identify the fungi associated with seedlings of two Pyroleae species, Pyrola chlorantha and Orthilia secunda. Our results indicate that similar to adult plants, Pyroleae seedlings can associate with a suite of ectomycorrhizal fungi. Some seedlings harboured single mycobionts, while others may have been inhabited by multiple fungi. The dominant seedling mycobiont of both Pyroleae species was a fungus of unknown trophic status in the order Sebacinales. This taxon was also the only one shared among seedlings of both investigated Pyroleae species. We discuss these results juxtaposed to orchids and one additional Pyrola species in the context of ontogenetic shifts in fungal host specificity for mycoheterotrophic nutrition.

  1. The life cycle of Prosorhynchoides carvajali (Trematoda: Bucephalidae) involving species of bivalve and fish hosts in the intertidal zone of central Chile. (United States)

    Muñoz, G; Valdivia, I; López, Z


    We describe the life cycle of the bucephalid Prosorhynchoides carvajali from the intertidal rocky zone of central Chile. To elucidate the life cycle of this digenean, two mytilid bivalves, Semimytilus algosus and Perumytilus purpuratus, and ten intertidal fish species belonging to the families Blenniidae, Tripterygiidae, Labrisomidae, Kyphosidae and Gobiesocidae were analysed for natural infections. In addition, experimental infections of fish were undertaken and molecular analyses were performed of several developmental stages of the digeneans in various host species. Experimental infections of fish were made from infected mytilids to determine which fish species were suitable for the metacercarial stage of Prosorhynchoides. We also determined the abundance and prevalence of metacercariae in natural infections in fish and found that they were lower than in the experimental infections. A molecular analysis showed that sporocysts from S. algosus were identical to metacercariae from five fish species and P. carvajali adults. Sporocysts isolated from P. purpuratus were similar to metacercaria found in one fish species only (G. laevifrons) but were different from P. carvajali, with 1.9-2.0% genetic divergence. Therefore, the complete life cycle of P. carvajali consists of the mytilid species S. algosus as the first intermediate host, at least five intertidal fish species as second intermediate hosts (Scartichthys viridis, Auchenionchus microcirrhis, Hypsoblennius sordidus, Helcogrammoides chilensis and Gobiesox marmoratus), two carnivorous fish as definitive hosts (Auchenionchus microcirrhis and A. variolosus) and one occasional definitive host (Syciases sanguineus). This is the second description of a life cycle of a marine digenean from Chile.

  2. Selective logging in tropical forests decreases the robustness of liana–tree interaction networks to the loss of host tree species (United States)

    Magrach, Ainhoa; Senior, Rebecca A.; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F.; Santamaria, Luis; Edwards, David P.


    Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the ‘health’ and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana–tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of ‘extinction debt’. PMID:26936241

  3. Selective logging in tropical forests decreases the robustness of liana-tree interaction networks to the loss of host tree species. (United States)

    Magrach, Ainhoa; Senior, Rebecca A; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F; Santamaria, Luis; Edwards, David P


    Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the 'health' and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana-tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of 'extinction debt'. © 2016 The Author(s).

  4. New host record of five Flavobacterium species associated with tropical fresh water farmed fishes from North India. (United States)

    Verma, Dev Kumar; Rathore, Gaurav


    Yellow pigmented, filamentous, Gram-negative bacteria belonging to genus Flavobacterium are commonly associated with infections in stressed fish. In this study, inter-species diversity of Flavobacterium was studied in apparently healthy freshwater farmed fishes. For this, ninety one yellow pigmented bacteria were isolated from skin and gill samples (n = 38) of three farmed fish species i.e. Labeo rohita, Catla catla and Cyprinus carpio. Among them, only twelve bacterial isolates (13.18%) were identified as Flavobacterium spp. on the basis of morphological, biochemical tests, partial 16S rDNA gene sequencing and phylogenetic analysis. On the basis of 16S rDNA gene sequencing, all the 12 isolates were 97.6-100% similar to six different formally described species of genus Flavobacterium. The 16S rDNA based phylogenetic analysis grouped these strains into six different clades. Of the 12 isolates, six strains (Fl9S1-6) grouped with F. suncheonense, two strains (Fl6I2, Fl6I3) with F. indicum and the rest four strains (Fl1A1, Fl2G1, Fl3H1 and Fl10T1) clustered with F. aquaticum, F. granuli, F. hercynium and F. terrae, respectively. None of these species except, F. hercynium were previously reported from fish. All the isolated Flavobacterium species possessed the ability of adhesion and biofilm formation to colonize the external surface of healthy fish. The present study is the first record of tropical freshwater farmed fishes as hosts to five environmentally associated species of the Flavobacterium.

  5. Which forest bird species are the main hosts of the tick, Ixodes ricinus, the vector of Borrelia burgdorferi sensu lato, during the breeding season? (United States)

    Marsot, M; Henry, P-Y; Vourc'h, G; Gasqui, P; Ferquel, E; Laignel, J; Grysan, M; Chapuis, J-L


    Wild birds are important hosts for vector-borne pathogens, especially those borne by ticks. However, few studies have been conducted on the role of different bird species within a community as hosts of vector-borne pathogens. This study addressed individual and species factors that could explain the burden of Ixodes ricinus on forest birds during the reproductive periods of both vectors and hosts. The goal was to identify which bird species contribute the most to the tick population at the community level. Birds were mist-netted on four plots in 2008 and on seven plots in 2009 in two forests (Sénart and Notre Dame, near Paris, France). The dependence of the tick load per bird upon environmental conditions (questing nymph density, year and plot) and on host species traits (species, age, sex, body size, vertical space use, level of innate and acquired immunity) was analysed. Finally, the relative contribution of each bird species to the local dynamics of ticks was estimated, while accounting for their respective abundance. Tick burden differed markedly between bird species and varied according to questing nymph density. Bird species with a high body mass, those that forage low in the vegetation, and those that had a high innate immune response and a high spleen mass were more likely to have a high tick burden. Four species (the Common Blackbird, Turdus merula, the European Robin, Erithacus rubecula, the Song Thrush, Turdus philomelos, and the Winter Wren, Troglodytes troglodytes) hosted more than 90% of the ticks in the local bird community. These species, and particularly T. merula which was host to a high proportion of the nymphs, are likely to contribute significantly to the circulation of pathogens for which they are competent, such as the agent of Lyme borreliosis.

  6. Yeast Communities of Diverse Drosophila Species: Comparison of Two Symbiont Groups in the Same Hosts



    The combination of ecological diversity with genetic and experimental tractability makes Drosophila a powerful model for the study of animal-associated microbial communities. Despite the known importance of yeasts in Drosophila physiology, behavior, and fitness, most recent work has focused on Drosophila-bacterial interactions. In order to get a more complete understanding of the Drosophila microbiome, we characterized the yeast communities associated with different Drosophila species collect...

  7. Geographic distribution and host plants of Raoiella indica and associated mite species in northern Venezuela. (United States)

    Vásquez, Carlos; de Moraes, Gilberto J


    The red palm mite (RPM), Raoiella indica Hirst (Acari: Tenuipalpidae), is an invasive pest in the New World, where it is currently considered a serious threat to coconut and banana crops. It was first reported from northern Venezuela in 2007. To determine its current distribution in this country, surveys were carried out from October 2008 to April 2010 on coconut (Cocos nucifera L.), banana (Musa spp.), ornamental plants and weeds in northern Venezuela. Higher population levels of RPM were registered on commercial coconut farms in Falcón and Sucre states but also on other plant species naturally growing along the coastal line in Anzoategui, Aragua, Carabobo, Monagas and Nueva Esparta states. Out of 34 botanical species evaluated, all RPM stages were observed only on eight arecaceous, one musaceous and one streliziaceous species, indicating that the pest developed and reproduced only on these plants. Mite specimens found on weeds were considered spurious events, as immature stages of the pest were never found on these. Amblyseius largoensis (Muma) (Acari: Phytoseiidae) was the most frequent predatory mite associated with RPM in all sampling sites. The results indicate that RPM has spread to extensive areas of northern Venezuela since its initial detection in Güiria, Sucre state. Considering the report of this pest mite in northern Brazil in the late 2009, additional samplings in southern Venezuela should be carried out, to evaluate the possible presence of RPM also in that region.

  8. Differential precocious sexual development of Proctoeces lintoni (Digenea: Fellodistomidae) in three sympatric species of keyhole limpets Fissurella spp. may affect transmission to the final host. (United States)

    Balboa, L; George-Nascimento, M; Ojeda, F P


    The prevalence, abundance, and developmental status of the digenetic trematode Proctoeces lintoni Siddiqui et Cable 1960 were compared in 3 species of keyhole limpets Fissurella. A total of 197 limpets was collected at Caleta Chome, south-central Chile. Fissurella picta and F. costata had the highest prevalence of infection, whereas F. picta showed the greatest abundance of parasites, which increased with host shell length. However, the frequency of P. lintoni specimens with eggs in the uterus was greatest in F. costata. These results suggest that an increased rate of development of a parasite in the intermediate host may shorten the residence time necessary for maturation in the final host. Thus, faster development of the parasite in F. costata suggests the possibility that the parasites transmitted through this host species have shorter maturation times in clingfishes than individuals transmitted via other limpet species.

  9. Interaction of bovine peripheral blood polymorphonuclear cells and Leptospira species; innate responses in the natural bovine reservoir host.

    Directory of Open Access Journals (Sweden)

    Jennifer H Wilson-Welder


    Full Text Available Cattle are the reservoir hosts of Leptospira borgpetersenii serovar Hardjo, and can also be reservoir hosts of other Leptospira species such as L. kirschneri, and L. interrogans. As a reservoir host, cattle shed Leptospira, infecting other animals, including humans. Previous studies with human and murine neutrophils have shown activation of neutrophil extracellular trap or NET formation, and upregulation of inflammatory mediators by neutrophils in the presence of Leptospira. Humans, companion animals and most widely studied models of Leptospirosis are of acute infection, hallmarked by systemic inflammatory response, neutrophilia and septicemia. In contrast, cattle exhibit chronic infection with few outward clinical signs aside from reproductive failure. Taking into consideration that there is host species variation in innate immunity, especially in pathogen recognition and response, the interaction of bovine peripheral blood polymorphonuclear cells (PMNs and several Leptospira strains was evaluated. Studies including bovine-adapted strains, human pathogen strains, a saprophyte and inactivated organisms. Incubation of PMNs with Leptospira did induce slight activation of neutrophil NETs, greater than unstimulated cells but less than the quantity from E. coli P4 stimulated PMNs. Very low but significant from non-stimulated, levels of reactive oxygen peroxides were produced in the presence of all Leptospira strains and E. coli P4. Similarly, significant levels of reactive nitrogen intermediaries (NO2 was produced from PMNs when incubated with the Leptospira strains and greater quantities in the presence of E. coli P4. PMNs incubated with Leptospira induced RNA transcripts of IL-1β, MIP-1α, and TNF-α, with greater amounts induced by live organisms when compared to heat-inactivated leptospires. Transcript for inflammatory cytokine IL-8 was also induced, at similar levels regardless of Leptospira strain or viability. However, incubation of

  10. Validity reassessment of Trichobilharzia species using Lymnaea stagnalis as the intermediate host. (United States)

    Rudolfová, J; Hampl, V; Bayssade-Dufour, C; Lockyer, A E; Littlewood, D T J; Horák, P


    The systematics within the genus Trichobilharzia is complicated. After the description of the type species Trichobilharzia ocellata, the name was routinely used for nearly all European findings of ocellate furcocercariae. T. ocellata was also described from North America and Japan. However, the identity of T. ocellata remains questionable. Comparison of data from the literature showed differences among various T. ocellata isolates and led us to the conclusion that the North American and the Japanese findings are not identical with European T. ocellata. In addition, the description of T. szidati corresponds with the recently reported European T. ocellata isolates. Sequence analysis of the ITS region confirmed that they are identical.

  11. Chrysomelids American diabroticines Hosts and natural enemies. Biology-feasibility for control of pest species (Crisomelidos Diabroticinos americanos Hospederos y enemigos naturales Biologia y factibili manejo especies plagas (United States)

    The chrysomelids in the Diabroticites include some of the most important pest species of the American continent. The chemical and management techniques used to date to control them are: crop rotation to prevent re-infection of host crops, especially in the species that display an egg diapause; insec...

  12. The phylogeny and life cycle of two species of Profilicollis (Acanthocephala: Polymorphidae) in marine hosts off the Pacific coast of Chile. (United States)

    Rodríguez, S M; D'Elía, G; Valdivia, N


    Resolving complex life cycles of parasites is a major goal of parasitological research. The aim of this study was to analyse the life cycle of two species of the genus Profilicollis, the taxonomy of which is still unstable and life cycles unclear. We extracted individuals of Profilicollis from two species of crustaceans (intermediate hosts) and four species of seagulls (definitive hosts) from sandy-shore and estuarine habitats along the south-east Pacific coast of Chile. Mitochondrial DNA analyses showed that two species of Profilicollis infected intermediate hosts from segregated habitats: while P. altmani larvae infected exclusively molecrabs of the genus Emerita from fully marine habitats, P. antarcticus larvae infected the crab Hemigrapsus crenulatus from estuarine habitats. Moreover, P. altmani completed its life cycle in four seagulls, Chroicocephalus maculipennis, Leucopheus pipixcan, Larus modestus and L. dominicanus, while P. antarcticus, on the other hand, completed its life cycle in the kelp gull L. dominicanus. Accordingly, our results show that two congeneric parasites use different and spatially segregated species as intermediate hosts, and both are capable of infecting one species of definitive hosts. As such, our analyses allow us to shed light on a complex interaction network.

  13. Trichinella infections in different host species of an endemic district of Serbia. (United States)

    Zivojinovic, M; Sofronic-Milosavljevic, Lj; Cvetkovic, J; Pozio, E; Interisano, M; Plavsic, B; Radojicic, S; Kulisic, Z


    Trichinella infections are endemic in the Balkan region of Europe. Though trichinellosis and agents thereof are serious problems for human health and animal husbandry, only a limited number of Trichinella isolates from Serbia have been identified at the species level so far. The aim of the present study was the surveillance and monitoring of Trichinella in domestic pigs and wild animals from the endemic district of Branicevo. Investigations performed during the 2009-2010 period revealed Trichinella infections in 344 out of 282,960 (0.12%) domestic pigs. Among wildlife, Trichinella infections were detected in 11 out of 94 (11.7%) wild boars (Sus scrofa), 7 out of 57 (12.3%) red foxes (Vulpes vulpes), 7 out of 13 (53.8%) golden jackals (Canis aureus), and in all three examined wolves (Canis lupus). Trichinella spiralis and Trichinella britovi were the only two species identified. T. britovi was identified in 31% of isolates from wildlife of the Branicevo district and T. spiralis was found in 53% of wild animals; mixed infections were observed in 16% of the animals examined. Findings form the basis of an information campaign for veterinary services, pig owners and the hunter's associations about the risk of the transmission of these zoonotic agents. The application of control programs as established at the Veterinary Specialist Institute of Pozarevac resulted in a decline in Trichinella infections among domestic pigs and the absence of human trichinellosis in the last three years in the Branicevo district.

  14. Geography and host species shape the evolutionary dynamics of U genogroup infectious hematopoietic necrosis virus (United States)

    Black, Allison; Breyta, Rachel; Bedford, Trevor; Kurath, Gael


    Infectious hematopoietic necrosis virus (IHNV) is a negative-sense RNA virus that infects wild and cultured salmonids throughout the Pacific Coastal United States and Canada, from California to Alaska. Although infection of adult fish is usually asymptomatic, juvenile infections can result in high mortality events that impact salmon hatchery programs and commercial aquaculture. We used epidemiological case data and genetic sequence data from a 303 nt portion of the viral glycoprotein gene to study the evolutionary dynamics of U genogroup IHNV in the Pacific Northwestern United States from 1971 to 2013. We identified 114 unique genotypes among 1,219 U genogroup IHNV isolates representing 619 virus detection events. We found evidence for two previously unidentified, broad subgroups within the U genogroup, which we designated ‘UC’ and ‘UP’. Epidemiologic records indicated that UP viruses were detected more frequently in sockeye salmon (Oncorhynchus nerka) and in coastal waters of Washington and Oregon, whereas UC viruses were detected primarily in Chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) in the Columbia River Basin, which is a large, complex watershed extending throughout much of interior Washington, Oregon, and Idaho. These findings were supported by phylogenetic analysis and by FST. Ancestral state reconstruction indicated that early UC viruses in the Columbia River Basin initially infected sockeye salmon but then emerged via host shifts into Chinook salmon and steelhead trout sometime during the 1980s. We postulate that the development of these subgroups within U genogroup was driven by selection pressure for viral adaptation to Chinook salmon and steelhead trout within the Columbia River Basin.

  15. Correlations between the ages of Alnus host species and the genetic diversity of associated endosymbiotic Frankia strains from nodules

    Institute of Scientific and Technical Information of China (English)

    DAI Yumei; ZHANG Chenggang; XIONG Zhi; ZHANG Zhongze


    Nodule samples were collected from four alder species: Alnus nepalensis, A. sibirica, A. tinctoria and A. mandshurica growing in different environments on Gaoligong Mountains,Yunnan Province of Southwest China and on Changbai Mountains, Jilin Province of Northeast China. PCR-RFLP analysis of the IGS between nifD and nifK genes was directly applied to uncultured Frankia strains in the nodules. A total of 21 restriction patterns were obtained. The Frankia population in the nodules of A. nepalensis had the highest genetic diversity among all four Frankia populations; by contrast, the population in the nodules of A. mandshurica had the lowest degree of divergence; the ones in the nodules of A. sibirica and A. tinctoria were intermediate. A dendrogram, which was constructed based on the genetic distance between the restriction patterns, indicated that Frankia strains from A. sibirica and A. tinctoria had a close genetic relationship. Frankia strains from A. nepalensis might be the ancestor of Frankia strains infecting other Alnus species. From these results and the inference of the ages of Alnus host species, it is deduced that there was a co-evolution between Alnus and its microsymbiont Frankia in China.

  16. A Compartmental Comparison of Major Lipid Species in a Coral-Symbiodinium Endosymbiosis: Evidence that the Coral Host Regulates Lipogenesis of Its Cytosolic Lipid Bodies.

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    Hung-Kai Chen

    Full Text Available The lipid body (LB formation in the host coral gastrodermal cell cytoplasm is a hallmark of the coral-Symbiodinium endosymbiosis, and such lipid-based entities are not found in endosymbiont-free cnidarian cells. Therefore, the elucidation of lipogenesis regulation in LBs and how it is related to the lipid metabolism of the host and endosymbiont could provide direct insight to understand the symbiosis mechanism. Herein, the lipid composition of host cells of the stony coral Euphyllia glabrescens, as well as that of their cytoplasmic LBs and in hospite Symbiodinium populations, was examined by high performance liquid chromatography (HPLC and gas chromatography/mass spectrometry (GC/MS, and six major lipid species were identified: wax esters, sterol esters, triacylglycerols, cholesterols, free fatty acids, and phospholipids. Their concentrations differed significantly between host coral cells, LBs, and Symbiodinium, suggesting compartmental regulation. WE were only present in the host coral and were particularly highly concentrated in LBs. Amongst the four species of WE, the monoene R = C18:1/R = C16 was found to be LB-specific and was not present in the host gastrodermal cell cytoplasm. Furthermore, the acyl pool profiles of the individual LB lipid species were more similar, but not equal to, those of the host gastrodermal cells in which they were located, indicating partially autonomous lipid metabolism in these LBs. Nevertheless, given the overall similarity in the host gastrodermal cell and LB lipid profiles, these data suggest that a significant portion of the LB lipids may be of host coral origin. Finally, lipid profiles of the in hospite Symbiodinium populations were significantly distinct from those of the cultured Symbiodinium, potentially suggesting a host regulation effect that may be fundamental to lipid metabolism in endosymbiotic associations involving clade C Symbiodinium.

  17. The New World Gibbobruchus Pic (Coleoptera, Chrysomelidae, Bruchinae): description of a new species and phylogenetic insights into the evolution of host associations and biogeography. (United States)

    Manfio, Daiara; Jorge, Isaac R; Morse, Geoffrey E; Ribeiro-Costa, Cibele S


    The seed beetle Gibbobruchus tridentatus Manfio, Jorge & Ribeiro-Costa sp. nov. is described from the Amazon basin in Brazil (Acre) and Ecuador (Napo), and is included in an updated key to the species of Gibbobruchus Pic. This new species and the recently described G. bergamini Manfio & Ribeiro-Costa are incorporated into a phylogenetic reanalysis of the genus and into a comparative analysis of host plant use and biogeography. Species groups previously proposed were supported and the evolutionary history in host plant-use shows Gibbobruchus conserved at tribe level, Cercideae (Caesalpinioideae), with coordination between biogeographic expansion and host genus shifts. Both species, Gibbobruchus tridentatus Manfio, Jorge & Ribeiro-Costa sp. nov. and G. bergamini, were placed within the group scurra (G. tridentatus (G. scurra (G. cavillator+G. bolivianus+G. bergamini))) and supported by one synapomorphy. Additionally, we update geographic distributions and host plant records. Two hosts, Bauhinia argentinensis Burkart and B. tarapotensis Benth. are recorded for the first time as hosts for the genus and for the subfamily.

  18. Radiation of the red algal parasite Congracilaria babae onto a secondary host species, Hydropuntia sp. (Gracilariaceae, Rhodophyta.

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    Poh-Kheng Ng

    Full Text Available Congracilaria babae was first reported as a red alga parasitic on the thallus of Gracilaria salicornia based on Japanese materials. It was circumscribed to have deep spermatangial cavities, coloration similar to its host and the absence of rhizoids. We observed a parasitic red alga with morphological and anatomical features suggestive of C. babae on a Hydropuntia species collected from Sabah, East Malaysia. We addressed the taxonomic affinities of the parasite growing on Hydropuntia sp. based on the DNA sequence of molecular markers from the nuclear, mitochondrial and plastid genomes (nuclear ITS region, mitochondrial cox1 gene and plastid rbcL gene. Phylogenetic analyses based on all genetic markers also implied the monophyly of the parasite from Hydropuntia sp. and C. babae, suggesting their conspecificity. The parasite from Hydropuntia sp. has a DNA signature characteristic to C. babae in having plastid rbcL gene sequence identical to G. salicornia. C. babae is likely to have evolved directly from G. salicornia and subsequently radiated onto a secondary host Hydropuntia sp. We also recommend the transfer of C. babae to the genus Gracilaria and propose a new combination, G. babae, based on the anatomical observations and molecular data.

  19. Molecular Phylogenies of Blastocystis Isolates from Different Hosts: Implications for Genetic Diversity, Identification of Species, and Zoonosis (United States)

    Noël, Christophe; Dufernez, Fabienne; Gerbod, Delphine; Edgcomb, Virginia P.; Delgado-Viscogliosi, Pilar; Ho, Lip-Chuen; Singh, Mulkit; Wintjens, René; Sogin, Mitchell L.; Capron, Monique; Pierce, Raymond; Zenner, Lionel; Viscogliosi, Eric


    Small-subunit (SSU) rRNA gene sequences were obtained by PCR from 12 Blastocystis isolates from humans, rats, and reptiles for which elongation factor 1α (EF-1α) gene sequences are already available. These new sequences were analyzed by the Bayesian method in a broad phylogeny including, for the first time, all Blastocystis sequences available in the databases. Phylogenetic trees identified seven well-resolved groups plus several discrete lineages that could represent newly defined clades. Comparative analysis of SSU rRNA- and EF-1α-based trees obtained by maximum-likelihood methods from a restricted sampling (13 isolates) revealed overall agreement between the two phylogenies. In spite of their morphological similarity, sequence divergence among Blastocystis isolates reflected considerable genetic diversity that could be correlated with the existence of potentially ≥12 different species within the genus. Based on this analysis and previous PCR-based genotype classification data, six of these major groups might consist of Blastocystis isolates from both humans and other animal hosts, confirming the low host specificity of Blastocystis. Our results also strongly suggest the existence of numerous zoonotic isolates with frequent animal-to-human and human-to-animal transmissions and of a large potential reservoir in animals for infections in humans. PMID:15634993

  20. When history repeats itself: exploring the genetic architecture of host-plant adaptation in two closely related lepidopteran species. (United States)

    Alexandre, Hermine; Ponsard, Sergine; Bourguet, Denis; Vitalis, Renaud; Audiot, Philippe; Cros-Arteil, Sandrine; Streiff, Réjane


    The genus Ostrinia includes two allopatric maize pests across Eurasia, namely the European corn borer (ECB, O. nubilalis) and the Asian corn borer (ACB, O. furnacalis). A third species, the Adzuki bean borer (ABB, O. scapulalis), occurs in sympatry with both the ECB and the ACB. The ABB mostly feeds on native dicots, which probably correspond to the ancestral host plant type for the genus Ostrinia. This situation offers the opportunity to characterize the two presumably independent adaptations or preadaptations to maize that occurred in the ECB and ACB. In the present study, we aimed at deciphering the genetic architecture of these two adaptations to maize, a monocot host plant recently introduced into Eurasia. To this end, we performed a genome scan analysis based on 684 AFLP markers in 12 populations of ECB, ACB and ABB. We detected 2 outlier AFLP loci when comparing French populations of the ECB and ABB, and 9 outliers when comparing Chinese populations of the ACB and ABB. These outliers were different in both countries, and we found no evidence of linkage disequilibrium between any two of them. These results suggest that adaptation or preadaptation to maize relies on a different genetic architecture in the ECB and ACB. However, this conclusion must be considered in light of the constraints inherent to genome scan approaches and of the intricate evolution of adaptation and reproductive isolation in the Ostrinia spp. complex.

  1. Comparison of probiotic lactobacilli and bifidobacteria effects, immune responses and rotavirus vaccines and infection in different host species. (United States)

    Vlasova, Anastasia N; Kandasamy, Sukumar; Chattha, Kuldeep S; Rajashekara, Gireesh; Saif, Linda J


    Different probiotic strains of Lactobacillus and Bifidobacterium genera possess significant and widely acknowledged health-promoting and immunomodulatory properties. They also provide an affordable means for prevention and treatment of various infectious, allergic and inflammatory conditions as demonstrated in numerous human and animal studies. Despite the ample evidence of protective effects of these probiotics against rotavirus (RV) infection and disease, the precise immune mechanisms of this protection remain largely undefined, because of limited mechanistic research possible in humans and investigated in the majority of animal models. Additionally, while most human clinical probiotic trials are well-standardized using the same strains, uniform dosages, regimens of the probiotic treatments and similar host age, animal studies often lack standardization, have variable experimental designs, and non-uniform and sometime limited selection of experimental variables or observational parameters. This review presents selected data on different probiotic strains of lactobacilli and bifidobacteria and summarizes the knowledge of their immunomodulatory properties and the associated protection against RV disease in diverse host species including neonates.

  2. Capacity Titration Technique for Determining the Solid Diffusion Coefficient of Intercalary Species within Insertion-host Materials

    Institute of Scientific and Technical Information of China (English)

    Xin Cun TANG; Tian Duo LI


    In this paper, the capacity titration technique (CT technique) was developed on basis of the RPG (ratio of potentio-charge capacity to galvano-charge capacity) method to continuously determine the solid diffusion coefficient D of the intercalary species within insertion-host materials with a small voltage region. The linear equations of D vs. q (value of ratio of the potentio-charge capacity to the galvano-charge capacity) were given in different range of q. By the CT technique,the Li+ solid diffusion coefficients D within LiMn2O4 at different voltages were determined. The results showed that the values of D varied from 3.447× 10-9 cm2/s to 7.60× 10-11cm2/s in the voltage range of charge from 3.3V to 4.3V as a function of voltage with "W" shape.

  3. Descriptions of four kleptoparasitic spiders of the genus Mysmenopsis (Araneae, Mysmenidae) and their potential host spider species in the genus Linothele (Araneae, Dipluridae) from Ecuador. (United States)

    Dupérré, Nadine; Tapia, Elicio


    Four new species of the genus Mysmenopsis are described: M. onorei n. sp., M. otonga n. sp., M. fernandoi n. sp. and M. chiquita n. sp. All species were collected in diplurid webs and are therefore assumed to be kleptoparasitic. Five potential host species of the genus Linothele (Dipluridae) that were collected with the symbionts are also described: Linothele yanachanka n. sp., L. pukachumpi n. sp., L. zaia n. sp., L. tsachilas n. sp. and L. quori n. sp.

  4. Metatranscriptome analysis reveals host-microbiome interactions in traps of carnivorous Genlisea species

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    Hieu X. Cao


    Full Text Available In the carnivorous plant genus Genlisea a unique lobster pot trapping mechanism supplements nutrition in nutrient-poor habitats. A wide spectrum of microbes frequently occurs in Genlisea’s leaf-derived traps without clear relevance for Genlisea carnivory. We sequenced the metatranscriptomes of subterrestrial traps versus the aerial chlorophyll-containing leaves of G. nigrocaulis and of G. hispidula. Ribosomal RNA assignment revealed soil-borne microbial diversity in Genlisea traps, with 92 genera of 19 phyla present in more than one sample. Microbes from 16 of these phyla including proteobacteria, green algae, amoebozoa, fungi, ciliates and metazoans, contributed additionally short-lived mRNA to the metatranscriptome. Furthermore, transcripts of 438 members of hydrolases (e.g. proteases, phosphatases, lipases, mainly resembling those of metazoans, ciliates and green algae, were found. Compared to aerial leaves, Genlisea traps displayed a transcriptional up-regulation of endogenous NADH oxidases generating reactive oxygen species as well as of acid phosphatases for prey digestion. A leaf-versus-trap transcriptome comparison reflects that carnivory provides inorganic P- and different forms of N-compounds (ammonium, nitrate, amino acid, oligopeptides and implies the need to protect trap cells against oxidative stress. The analysis elucidates a complex food web inside the Genlisea traps, and suggests ecological relationships between this plant genus and its entrapped microbiome.

  5. Laboratory Investigations of African Pouched Rats (Cricetomys gambianus as a Potential Reservoir Host Species for Monkeypox Virus.

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    Christina L Hutson

    Full Text Available Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s. In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats and this rodent species' competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4 or West African (W-MPXV: n = 4; an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV between 3 and 27 days post infection (p.i. (up to 1X108 pfu/ml, with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

  6. Evidence for potential of managing some African fruit fly species (Diptera: Tephritidae) using the mango fruit fly host-marking pheromone. (United States)

    Kachigamba, Donald L; Ekesi, Sunday; Ndungu, Mary W; Gitonga, Linus M; Teal, Peter E A; Torto, Baldwyn


    We investigated conspecific and heterospecific oviposition host discrimination among four economically important fruit fly pests of mango in Africa (Ceratitis capitata, Wiedemann; C. fasciventris, Bezzi; C. rosa, Karsch, and C. cosyra, Walker) with regard to host-marking behavior and fecal matter aqueous solutions. The objective of the study was to get insight into the potential of managing these pests using the host-marking technique. Observations were done on mango slices marked by the flies and treated with aqueous solutions of fecal matter of the flies, respectively. In both host-marking and fecal matter experiments, C. cosyra, which is the most destructive species of the four on mango, was exceptional. It only discriminated against hosts treated with its fecal matter but with lower sensitivity while C. capitata and C.fasciventris discriminated against hosts marked by it or treated with its fecal matter and with higher sensitivity. Our results provide evidence for potential of managing some of the major fruit fly species infesting mango in Africa using the host-marking pheromone of the mango fruit fly, C. cosyra.

  7. Exploitative Competition and Risk of Parasitism in Two Host Ant Species: The Roles of Habitat Complexity, Body Size, and Behavioral Dominance

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    Elliot B. Wilkinson


    Full Text Available Habitat structural complexity can slow resource discovery by ants but can also lower the risk of parasitism during foraging. The relative importance of these two ecological facets of habitat complexity may differ in a species-specific manner and thus may be important in the outcome of exploitative competition over food resources. For the host ant species Pheidole diversipilosa and P. bicarinata, we used in situ experimental manipulations to explore whether the effects of habitat complexity on exploitative competition depended on host body size and behavioral dominance, two characteristics likely to affect mobility and utilization of refuge from specialist Dipteran parasitoids (Apocephalus orthocladius and A. pugilist, resp.. We found that habitat complexity affected the resource discovery and harvest components of exploitative competition in an opposing fashion for each species and discuss these results in light of the differences in body size and behavioral dominance between the two hosts.

  8. Seed specific expression and analysis of recombinant human adenosine deaminase (hADA) in three host plant species. (United States)

    Doshi, Ketan M; Loukanina, Natalia N; Polowick, Patricia L; Holbrook, Larry A


    The plant seed is a leading platform amongst plant-based storage systems for the production of recombinant proteins. In this study, we compared the activity of human adenosine deaminase (hADA) expressed in transgenic seeds of three different plant species: pea (Pisum sativum L.), Nicotiana benthamiana L. and tarwi (Lupinus mutabilis Sweet). All three species were transformed with the same expression vector containing the hADA gene driven by the seed-specific promoter LegA2 with an apoplast targeting pinII signal peptide. During the study, several independent transgenic lines were generated and screened from each plant species and only lines with a single copy of the gene of interest were used for hADA expression analysis. A stable transgenic canola line expressing the ADA protein, under the control of 35S constitutive promoter was used as both as a positive control and for comparative study with the seed specific promoter. Significant differences were detected in the expression of hADA. The highest activity of the hADA enzyme (Units/g seed) was reported in tarwi (4.26 U/g) followed by pea (3.23 U/g) and Nicotiana benthamiana (1.69 U/g). The expression of mouse ADA in canola was very low in both seed and leaf tissue compared to other host plants, confirming higher activity of seed specific promoter. Altogether, these results suggest that tarwi could be an excellent candidate for the production of valuable recombinant proteins.

  9. Spatial distributions of two species of monogeneans on the gills of Siganus fuscescens (Houttuyn) and their seasonal dynamics in caged versus wild-caught hosts. (United States)

    Yang, Tingbao; Liu, Jifang; Gibson, David I; Dong, An


    Two monogeneans species, Polylabris mamaevi Ogawa & Egusa, 1980 and Tetrancistrum nebulosi Young, 1967, are sympatric on the gills of Siganus fuscescens (Houttugn, 1782) in the South China Sea. An investigation into their distribution on the host's gills based on monthly samples from both wild and caged populations revealed that these 2 species co-occurred on the same gill arches, but they were segregated. P. mamaevi attached to the distal half of the gill filaments, whereas T. nebulosi attached to the proximal half. This difference may partly be attributed to microhabitat specialization. Microhabitat distributions were intensity dependent for both species. As intensity increased, monogeneans were increasingly found on the second, third, and even fourth gill arches, and niche breadths increased. The changes in distribution and niche breadths at the host gill arch level in relation to differences in host size and sampling period were considered to represent a functional response to increased intensity. Differences in host resources, in either net-caged or wild populations, did not significantly influence the parasite distributions at the host gill arch level. Simultaneous infections of these 2 species were common, but there was no evidence of negative interspecific interactions.

  10. A review of Epipenaeon ingens Nobili, 1906 (Isopoda: Bopyridae) host species and documentation of a new host, Metapenaeopsis stridulans (Alcock, 1905) (Decapoda: Penaeidae)

    Institute of Scientific and Technical Information of China (English)



    We collected 3 596 Metapenaeopsis stridulans (Decapoda: Penaeidae) from the southeast coast of India between January and December 2007. Sixty three specimens (43 females and 18 males) were parasitized by the bopyrid isopod Epipenaeon ingens (Isopoda: Bopyridae). This is the first report of the occurrence of E. ingens in this host; therefore, it was considered as a new host record. The highest level of infestation (3.2%) occurred in October 2007, coincident with observations of gravid females (9). The total prevalence and presence of gravid females were 17.46% and 28%, respectively. Infestation caused a characteristic bulge of the branchial chamber, growth retardation, and degeneration of the sex organs, but had no effect on the host weight.

  11. Are gall midge species (Diptera, Cecidomyiidae host-plant specialists? Espécies de moscas galhadoras (Diptera, Cecidomyiidae são especialistas em plantas hospedeiras?

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    Marco Antonio A. Carneiro


    Full Text Available Despite the speciose fauna of gall-inducing insects in the Neotropical region, little is known about their taxonomy. On the other hand, gall morphotypes associated with host species have been extensively used as a surrogate of the inducer species worldwide. This study reviewed the described gall midges and their galls to test the generalization on the use of gall morphotypes as surrogates of gall midge species in the Brazilian fauna. We compiled taxonomic and biological data for 196 gall midge species recorded on 128 host plant species. Ninety two percent of those species were monophagous, inducing galls on a single host plant species, whereas only 5.6% species were oligophagous, inducing galls on more than one congeneric host plant species. Only four species induced galls on more than one host plant genus. We conclude that gall morphotypes associated with information on the host plant species and attacked organs are reliable surrogates of the gall-inducing species.Apesar do elevado número de espécies da fauna de insetos indutores de galhas na região Neotropical, muito pouco espécies foram descritas. Por outro lado, o morfotipo da galha associado com a espécie da planta hospedeira é em todo o mundo amplamente utilizado como um indicador da espécie de inseto indutor. Este estudo revê as espécies de cecidommídeos descritos e suas galhas para verificar a generalização do uso da morfologia da galha como indicador da espécie de cecidomíideo na fauna brasileira. Nós compilamos dados biológicos e taxonômicos de 196 espécies de cecidomiídeos em 128 espécies de plantas no Brasil. Noventa e dois porcento destas espécies foram monófagas, induzindo galhas em uma única espécie de planta hospedeira, enquanto somente 5,6% das espécies foram oligófagas, induzindo galhas em mais de uma espécie de planta do mesmo gênero. Somente quatro espécies induzem galhas em espécies de plantas de gêneros diferentes. Nós concluímos que o morfo

  12. The ocellated eagle ray, Aetobatus ocellatus (Myliobatiformes: Myliobatidae), from Borneo and northern Australia as host of four new species of Hornellobothrium (Cestoda: Lecanicephalidea). (United States)

    Mojica, Kendra R; Jensen, Kirsten; Caira, Janine N


    Four new species are described in the lecanicephalidean genus Hornellobothrium from the ocellated eagle ray, Aetobatus ocellatus, from Australia and Indonesian Borneo. The species possess flat, laterally expanded immature proglottids and a small internal, glandular apical organ diagnostic of the genus. To date, only 2 valid species are recognized in the genus: Hornellobothrium cobraformis Shipley & Hornell, 1906 , from " Aetobatus narinari " from Sri Lanka, and Hornellobothrium extensivum Jensen, 2005 , from A. ocellatus , also from Australia. The new species differ from H. cobraformis in the shape of the apical organ and mature proglottids, and from H. extensivum in testes number and scolex dimensions. The new species can be distinguished from one another based on the following combination of features: Hornellobothrium gerdaae n. sp. possesses testes arranged in 2 layers and lacks post-ovarian vitelline follicles; Hornellobothrium iotakotta n. sp. has a single column of 4 testes and lacks spiniform microtriches on the distal bothridial surface; both Hornellobothrium kolossakotta n. sp. and Hornellobothrium najaforme n. sp. possess a single column of 6 testes, but H. najaforme n. sp. is a longer worm with a greater number of laterally expanded immature proglottids. Host associations suggest this genus is potentially limited to A. ocellatus . While reports of up to 9 lecanicephalidean congeners in a single host species exist, they are considered dubious and in need of verification, mainly because of host identification issues. This study demonstrates the presence of at least 5 species of Hornellobothrium in A. ocellatus . Insufficient sampling of this host species across the Indo-Pacific and at each locality may account for the apparent restricted distribution of species of Hornellobothrium.

  13. New insights into the molecular phylogeny of Balantidium (Ciliophora, Vetibuliferida) based on the analysis of new sequences of species from fish hosts. (United States)

    Li, Ming; Ponce-Gordo, Francisco; Grim, J Norman; Wang, Chong; Nilsen, Frank


    We obtained sequences of the small subunit ribosomal RNA (rRNA) for two new isolates of Balantidium from fishes, Balantidium polyvacuolum and Balantidium ctenopharingodoni. This is the first introduction of molecular data of Balantidium species from fish hosts in the phylogenetic analyses of the ciliate subclass Trichostomatia. Despite the fact that these species share morphological characteristics common to other species of Balantidium, the phylogenetic analysis of their sequences has shown that they are to be placed in a different branch closely related to the so-called Australian clade. Thus, our results indicate that the genus Balantidium is polyphyletic and possibly should be represented by two different genera; however, the analysis of more species from other poikilothermic hosts (amphibians, reptiles) should be made before a revised taxonomical proposal could be made.

  14. Detection of parasitizing coccidia and determination of host crane species, sex and genotype by faecal DNA analysis. (United States)

    Honma, H; Suyama, Y; Nakai, Y


    In Japan, the three main crane species are the endangered red-crowned crane (Grus japonensis) inhabiting Hokkaido, the northernmost island of Japan; the vulnerable hooded crane (Grus monacha); and the vulnerable white-naped crane (Grus vipio). Both the hooded and white-naped cranes migrate in winter to Izumi in Kyushu, the southern island of Japan. In this study, we investigated the cranes and their coccidian parasites, through a targeted molecular approach using faecal DNA to develop a noninvasive method for infectious disease research. To determine the origin of noninvasively collected faecal samples, host species were identified by sequencing a region of approximately 470 bp of the mitochondrial 16S ribosomal RNA gene in the faecal DNA. Furthermore, to avoid sample redundancy, individual determination was performed by fragment analysis using microsatellite and sex-linked markers. For microsatellite genotyping, previously reported markers and markers isolated in this study were examined, and seven loci for red-crowned cranes, eight for hooded cranes and six for white-naped cranes displayed polymorphisms. A low error rate was demonstrated by comparing microsatellite data generated from faecal DNA samples with that generated from feather DNA samples, indicating a high reliability. Polymerase chain reaction-based capillary electrophoresis (PCR-CE), employing genetic markers in the second internal transcribed spacer (ITS2) of nuclear ribosomal DNA, was employed to detect crane coccidia. The sensitivity of detection of PCR-CE using faecal DNA was inferior to that with traditional microscopy; however, our results suggest that PCR-CE can depict crane coccidia diversity with higher resolution and it is a useful tool to characterize community composition of coccidia in detail.

  15. Host-species transferrin receptor 1 orthologs are cellular receptors for nonpathogenic new world clade B arenaviruses.

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    Jonathan Abraham


    Full Text Available The ability of a New World (NW clade B arenavirus to enter cells using human transferrin receptor 1 (TfR1 strictly correlates with its ability to cause hemorrhagic fever. Amapari (AMAV and Tacaribe (TCRV, two nonpathogenic NW clade B arenaviruses that do not use human TfR1, are closely related to the NW arenaviruses that cause hemorrhagic fevers. Here we show that pseudotyped viruses bearing the surface glycoprotein (GP of AMAV or TCRV can infect cells using the TfR1 orthologs of several mammalian species, including those of their respective natural hosts, the small rodent Neacomys spinosus and the fruit bat Artibeus jamaicensis. Mutation of one residue in human TfR1 makes it a functional receptor for TCRV, and mutation of four residues makes it a functional receptor for AMAV. Our data support an in vivo role for TfR1 in the replication of most, if not all, NW clade B arenaviruses, and suggest that with modest changes in their GPs the nonpathogenic arenaviruses could use human TfR1 and emerge as human pathogens.

  16. Commensal Bacteroides species induce colitis in host-genotype-specific fashion in a mouse model of inflammatory bowel disease (United States)

    Bloom, Seth M.; Bijanki, Vinieth N.; Nava, Gerardo M.; Sun, Lulu; Malvin, Nicole P.; Donermeyer, David L.; Dunne, W. Michael; Allen, Paul M.; Stappenbeck, Thaddeus S.


    SUMMARY The intestinal microbiota is important for induction of inflammatory bowel disease (IBD). IBD is associated with complex shifts in microbiota composition, but it is unclear whether specific bacterial subsets induce IBD and, if so, whether their proportions in the microbiota are altered during disease. Here we fulfilled Koch’s postulates in host-genotype-specific fashion using a mouse model of IBD with human-relevant disease-susceptibility mutations. From screening experiments we isolated common commensal Bacteroides species, introduced them into antibiotic-pretreated mice, and quantitatively re-isolated them in culture. The bacteria colonized IBD-susceptible and non-susceptible mice equivalently, but induced disease exclusively in susceptible animals. Conversely, commensal Enterobacteriaceae were >100-fold enriched during spontaneous disease but an Enterobacteriaceae isolate failed to induce disease in antibiotic-pretreated mice despite robust colonization. We thus demonstrate that IBD-associated microbiota alterations do not necessarily reflect underlying disease etiology. These findings establish important experimental criteria and a conceptual framework for understanding microbial contributions to IBD. PMID:21575910

  17. Genetic and morphological diversity of Trisetacus species (Eriophyoidea: Phytoptidae) associated with coniferous trees in Poland: phylogeny, barcoding, host and habitat specialization. (United States)

    Lewandowski, Mariusz; Skoracka, Anna; Szydło, Wiktoria; Kozak, Marcin; Druciarek, Tobiasz; Griffiths, Don A


    Eriophyoid species belonging to the genus Trisetacus are economically important as pests of conifers. A narrow host specialization to conifers and some unique morphological characteristics have made these mites interesting subjects for scientific inquiry. In this study, we assessed morphological and genetic variation of seven Trisetacus species originating from six coniferous hosts in Poland by morphometric analysis and molecular sequencing of the mitochondrial cytochrome oxidase subunit I gene and the nuclear D2 region of 28S rDNA. The results confirmed the monophyly of the genus Trisetacus as well as the monophyly of five of the seven species studied. Both DNA sequences were effective in discriminating between six of the seven species tested. Host-dependent genetic and morphological variation in T. silvestris and T. relocatus, and habitat-dependent genetic and morphological variation in T. juniperinus were detected, suggesting the existence of races or even distinct species within these Trisetacus taxa. This is the first molecular phylogenetic analysis of the Trisetacus species. The findings presented here will stimulate further investigations on the evolutionary relationships of Trisetacus as well as the entire Phytoptidae family.

  18. Biology and host specificity of Coelocephalapion gandolfoi Kissinger (Brentidae) a promising candidate for the biological control of invasive Prosopis species (Leguminosae) in South Africa (United States)

    Invasive Prosopis species (Leguminosae) (mesquite) pose a significant threat to biodiversity, pasture production, and water resources in South Africa. In an attempt to contain the spread of this noxious weed the South African authorities have supported the introduction of host-specific and damaging...

  19. The Microbiome of Field-Caught and Laboratory-Adapted Australian Tephritid Fruit Fly Species with Different Host Plant Use and Specialisation. (United States)

    Morrow, J L; Frommer, M; Shearman, D C A; Riegler, M


    Tephritid fruit fly species display a diversity of host plant specialisation on a scale from monophagy to polyphagy. Furthermore, while some species prefer ripening fruit, a few are restricted to damaged or rotting fruit. Such a diversity of host plant use may be reflected in the microbial symbiont diversity of tephritids and their grade of dependency on their microbiomes. Here, we investigated the microbiome of six tephritid species from three genera, including species that are polyphagous pests (Bactrocera tryoni, Bactrocera neohumeralis, Bactrocera jarvisi, Ceratitis capitata) and a monophagous specialist (Bactrocera cacuminata). These were compared with the microbiome of a non-pestiferous but polyphagous tephritid species that is restricted to damaged or rotting fruit (Dirioxa pornia). The bacterial community associated with whole fruit flies was analysed by 16S ribosomal DNA (rDNA) amplicon pyrosequencing to detect potential drivers of taxonomic composition. Overall, the dominant bacterial families were Enterobacteriaceae and Acetobacteraceae (both Proteobacteria), and Streptococcaceae and Enterococcaceae (both Firmicutes). Comparisons across species and genera found different microbial composition in the three tephritid genera, but limited consistent differentiation between Bactrocera species. Within Bactrocera species, differentiation of microbial composition seemed to be influenced by the environment, possibly including their diets; beyond this, tephritid species identity or ecology also had an effect. The microbiome of D. pornia was most distinct from the other five species, which may be due to its ecologically different niche of rotting or damaged fruit, as opposed to ripening fruit favoured by the other species. Our study is the first amplicon pyrosequencing study to compare the microbiomes of tephritid species and thus delivers important information about the turnover of microbial diversity within and between fruit fly species and their potential

  20. Host range and distribution of small mammal fleas in South Africa, with a focus on species of medical and veterinary importance. (United States)

    VAN DER Mescht, L; Matthee, S


    The host range and distribution of flea species on rodents and insectivores across multiple vegetation types in South Africa were investigated. Habitat suitability for flea species considered as important vectors of disease in humans and domestic animals was modelled. Data originated from fleas that were recovered from small mammals captured at 29 localities during 2009-2013 and published literature searched for flea records. Climate-based predictor variables, widely used in arthropod vector distribution, were selected and habitat suitability modelled for 10 flea vector species. A total of 2469 flea individuals representing 33 species and subspecies were collected from 1185 small mammals. Ten of each of the flea and rodent species are plague vectors and reservoirs, respectively. Multiple novel flea-host associations and locality records were noted. Three vector species were recorded from insectivores. Geographic distributions of flea species ranged from broad, across-biome distributions to narrower distributions within one or two biomes. Habitat suitability models performed excellently for the majority of flea vectors and identified regions of summer and all-year rainfall as representing suitable habitats for most vector species. Current knowledge of vector and disease ecology can benefit from similar sampling approaches that will be important not only for South Africa, but also for the sub-region. © 2017 The Royal Entomological Society.

  1. Disentangling Peronospora on Papaver: phylogenetics, taxonomy, nomenclature and host range of downy mildew of opium poppy (Papaver somniferum and related species.

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    Hermann Voglmayr

    Full Text Available Based on sequence data from ITS rDNA, cox1 and cox2, six Peronospora species are recognised as phylogenetically distinct on various Papaver species. The host ranges of the four already described species P. arborescens, P. argemones, P. cristata and P. meconopsidis are clarified. Based on sequence data and morphology, two new species, P. apula and P. somniferi, are described from Papaver apulum and P. somniferum, respectively. The second Peronospora species parasitizing Papaver somniferum, that was only recently recorded as Peronospora cristata from Tasmania, is shown to represent a distinct taxon, P. meconopsidis, originally described from Meconopsis cambrica. It is shown that P. meconopsidis on Papaver somniferum is also present and widespread in Europe and Asia, but has been overlooked due to confusion with P. somniferi and due to less prominent, localized disease symptoms. Oospores are reported for the first time for P. meconopsidis from Asian collections on Papaver somniferum. Morphological descriptions, illustrations and a key are provided for all described Peronospora species on Papaver. cox1 and cox2 sequence data are confirmed as equally good barcoding loci for reliable Peronospora species identification, whereas ITS rDNA does sometimes not resolve species boundaries. Molecular phylogenetic data reveal high host specificity of Peronospora on Papaver, which has the important phytopathological implication that wild Papaver spp. cannot play any role as primary inoculum source for downy mildew epidemics in cultivated opium poppy crops.

  2. Sequential Utilization of Hosts from Different Fly Families by Genetically Distinct, Sympatric Populations within the Entomophthora muscae Species Complex


    Gryganskyi, Andrii P.; Humber, Richard A.; Stajich, Jason E.; Bradley Mullens; Anishchenko, Iryna M.; Rytas Vilgalys


    The fungus Entomophthora muscae (Entomophthoromycota, Entomophthorales, Entomophthoraceae) is a widespread insect pathogen responsible for fatal epizootic events in many dipteran fly hosts. During epizootics in 2011 and 2012 in Durham, North Carolina, we observed a transition of fungal infections from one host, the plant-feeding fly Delia radicum, to a second host, the predatory fly Coenosia tigrina. Infections first appeared on Delia in the middle of March, but by the end of May, Coenosia co...

  3. A test of the nest sanitation hypothesis for the evolution of foreign egg rejection in an avian brood parasite rejecter host species (United States)

    Luro, Alec B.; Hauber, Mark E.


    Hosts of avian brood parasites have evolved diverse defenses to avoid the costs associated with raising brood parasite nestlings. In egg ejection, the host recognizes and removes foreign eggs laid in its nest. Nest sanitation, a behavior similar in motor pattern to egg ejection, has been proposed repeatedly as a potential pre-adaptation to egg ejection. Here, we separately placed blue 3D-printed, brown-headed cowbird ( Molothrus ater) eggs known to elicit interindividual variation in ejection responses and semi-natural leaves into American robins' ( Turdus migratorius) nests to test proximate predictions that (1) rejecter hosts should sanitize debris from nests more frequently and consistently than accepter hosts and (2) hosts that sanitize their nests of debris prior to the presentation of a foreign egg will be more likely to eject the foreign egg. Egg ejection responses were highly repeatable within individuals yet variable between them, but were not influenced by prior exposure to debris, nor related to sanitation tendencies as a whole, because nearly all individuals sanitized their nests. Additionally, we collected published data for eight different host species to test for a potential positive correlation between sanitation and egg ejection. We found no significant correlation between nest sanitation and egg ejection rates; however, our comparative analysis was limited to a sample size of 8, and we advise that more data from additional species are necessary to properly address interspecific tests of the pre-adaptation hypothesis. In lack of support for the nest sanitation hypothesis, our study suggests that, within individuals, foreign egg ejection is distinct from nest sanitation tendencies, and sanitation and foreign egg ejection may not correlate across species.

  4. Egg morphology, laying behavior and record of the host plants of Ricania speculum (Walker, 1851), a new alien species for Europe (Hemiptera: Ricaniidae). (United States)

    Rossi, Elisabetta; Stroiński, Adam; Lucchi, Andrea


    The exotic planthopper, Ricania speculum (Ricaniidae) was recently detected in Liguria, in northern Italy, and recorded as a first alert for Europe. The first morphological description of eggs and laying behavior are given. Eggs are inserted into the woody tissue of a wide range of different host plants in such a unique manner among native and alien planthoppers of Italy that it can be used to describe the prevalence and diffusion of the species in new environments, though in the absence of juveniles and/or adults. In addition, the paper lists the host plants utilized for egg laying and describes the eggs.

  5. Influence of Host Plant Species and Flush Growth Stage on the Asian Citrus Psyllid, Diaphorina citri Kuwayama

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    Stephen L.C. Teck


    Full Text Available Problem statement: In order to establish the important host range of D. citri, the performance of this psyllid on different rutacous host plants was assessed. Apparent regional differences in host preferences of D. citri as noted above and the need for empirical knowledge of its host preferences in Malaysia where it is lacking. Approach: Experiments on host plant preference between citrus, jasmine orange and curry leaf were conducted over a period of 14 days in the field cage in October 1998 at the agricultural research centre, Semonggok, 15 km from Kuching, Kuching Division, Sarawak in Malaysia. Results: A comparative life cycle study of the Asian Citrus Psyllid Diaphorina citri Kuwayama on three different Rutaceous plant hosts namely citrus, jasmine orange and curry leaf plants was conducted inside the temperature controlled growth chamber maintain at 26 ± 1°C temperature, 75-80% relative humidity with artificial illumination intensity of 10,000 lux equipped with a photoperiod of 14:10 h light: dark regime to permit normal growth. Conclusion: The screenhouse studies confirmed that D. citri can colonise and breed on citrus, jasmine orange and curry leaf plant and that jasmine orange is the preferred host. It is also confirmed that females prefer to oviposit on immature flush 3-10 mm in length. In growth chamber experiments the life cycle of the psyllid was 18.5 days on jasmine orange, 19.0 days on citrus and 23.0 days on curry leaf.

  6. Invasion biology in non-free-living species: interactions between abiotic (climatic) and biotic (host availability) factors in geographical space in crayfish commensals (Ostracoda, Entocytheridae). (United States)

    Mestre, Alexandre; Aguilar-Alberola, Josep A; Baldry, David; Balkis, Husamettin; Ellis, Adam; Gil-Delgado, Jose A; Grabow, Karsten; Klobučar, Göran; Kouba, Antonín; Maguire, Ivana; Martens, Andreas; Mülayim, Ayşegül; Rueda, Juan; Scharf, Burkhard; Soes, Menno; S Monrós, Juan; Mesquita-Joanes, Francesc


    In invasion processes, both abiotic and biotic factors are considered essential, but the latter are usually disregarded when modeling the potential spread of exotic species. In the framework of set theory, interactions between biotic (B), abiotic (A), and movement-related (M) factors in the geographical space can be hypothesized with BAM diagrams and tested using ecological niche models (ENMs) to estimate A and B areas. The main aim of our survey was to evaluate the interactions between abiotic (climatic) and biotic (host availability) factors in geographical space for exotic symbionts (i.e., non-free-living species), using ENM techniques combined with a BAM framework and using exotic Entocytheridae (Ostracoda) found in Europe as model organisms. We carried out an extensive survey to evaluate the distribution of entocytherids hosted by crayfish in Europe by checking 94 European localities and 12 crayfish species. Both exotic entocytherid species found, Ankylocythere sinuosa and Uncinocythere occidentalis, were widely distributed in W Europe living on the exotic crayfish species Procambarus clarkii and Pacifastacus leniusculus, respectively. No entocytherids were observed in the remaining crayfish species. The suitable area for A. sinuosa was mainly restricted by its own limitations to minimum temperatures in W and N Europe and precipitation seasonality in circum-Mediterranean areas. Uncinocythere occidentalis was mostly restricted by host availability in circum-Mediterranean regions due to limitations of P. leniusculus to higher precipitation seasonality and maximum temperatures. The combination of ENMs with set theory allows studying the invasive biology of symbionts and provides clues about biogeographic barriers due to abiotic or biotic factors limiting the expansion of the symbiont in different regions of the invasive range. The relative importance of abiotic and biotic factors on geographical space can then be assessed and applied in conservation plans. This

  7. Taxonomy, host-plant associations and phylogeny of African Crotalaria-feeding seed beetles (Coleoptera, Chrysomelidae, Bruchinae): the Conicobruchus strangulatus (Fåhraeus) species group. (United States)

    Le Ru, Bruno P; Delobel, Alex; György, Zoltán; Genson, Gwenaëlle; Kergoat, Gael J


    A small group of six morphologically related seed beetles (Coleoptera: Chrysomelidae: Bruchinae) belonging to the Conicobruchus genus is reviewed. Species in this group for which host-plants are known feed on various species of Crotalaria (Fabaceae, Crotalarieae). Here we provide diagnoses and a dichotomous key for all six species. The following synonymies are proposed: Conicobruchus cicatricosus (Fåhraeus, 1839) (= Bruchus cicatricosus pallidioripennis Pic, 1941) syn. nov.; Conicobruchus strangulatus (Fåhraeus, 1839) (= Bruchus hargreavesi Pic, 1933) syn. nov. The corresponding Conicobruchus strangulatus species group is hereby designated. New host-plant data are also included, which correspond to the results of recent collections of legume pods in East Africa. In addition we carried out molecular phylogenetic analyses on a representative sampling of Conicobruchus species (including the six species of interest). The latter allow us to assess the monophyly of the group of interest and to unravel their evolutionary relationships. Molecular phylogenetic analyses also indicate that at least two lineages of Conicobruchus successfully shifted toward Crotalarieae during the course of their diversification. 

  8. Prey preference and host suitability of the predatory and parasitoid carabid beetle, Lebia grandis, for several species of Leptinotarsa beetles


    Donald C. Weber; Rowley, Daniel L.; Greenstone, Matthew H.; Athanas, Michael M.


    Lebia grandis (Coleoptera: Carabidae), recorded as a parasitoid only on Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae), is capable of parasitizing the false potato beetle, L. juncta, and also L. haldemani. Historical records show that L. decemlineata, while the only recorded host, was not present in much of the original range of L. grandis, and may not have been its host prior to its expansion into eastern North America, where L. juncta is endemic. Our laborator...

  9. Systematic relationships and cospeciation of bacterial endosymbionts and their carpenter ant host species: proposal of the new taxon Candidatus Blochmannia gen. nov. (United States)

    Sauer, C; Stackebrandt, E; Gadau, J; Hölldobler, B; Gross, R


    The systematic relationships of intracellular bacteria of 13 Camponotus species (carpenter ants) from America and Europe were compared to those of their hosts. Phylogenetic trees of the bacteria and the ants were based on 16S rDNA (rrs) gene sequences and mitochondrial cytochrome oxidase subunit I (COI) gene sequences, respectively. The bacterial endosymbionts of Camponotus spp. form a distinct lineage in the y-subclass of the Proteobacteria. The taxa most closely related to these bacteria are endosymbionts of aphids and the tsetse fly. The bacterial and host phylogenies deduced from the sequence data show a high degree of congruence, providing significant evidence for cospeciation of the bacteria and the ants and a maternal transmission route of the symbionts. The cloned rrs genes of the endosymbionts contain putative intervening sequences (IVSs) with a much lower G+C content than the mean of the respective rrs genes. By in situ hybridization specific 16S rDNA oligonucleotide probes verified the presence of the bacteria within tissues of three of the eukaryotic hosts. It is proposed that the endosymbionts of these three carpenter ants be assigned to a new taxon 'Candidatus Blochmannia gen. nov.' with the symbionts of the individual ants being species named according to their host, 'Candidatus Blochmannia floridanus sp. nov.', 'Candidatus Blochmannia herculeanus sp. nov.' and 'Candidatus Blochmannia rufipes sp. nov.'.

  10. Ligophorus species (Monogenea: Ancyrocephalidae) from Mugil cephalus (Teleostei: Mugilidae) off Morocco with the description of a new species and remarks about the use of Ligophorus spp. as biological markers of host populations. (United States)

    El Hafidi, Fouzia; Rkhami, Ouafae Berrada; de Buron, Isaure; Durand, Jean-Dominique; Pariselle, Antoine


    Gill monogenean species of Ligophorus Euzet et Suriano, 1977 were studied from the teleost Mugil cephalus Linneaus (Mugilidae) from the Mediterranean and Atlantic coasts of Morocco. We report the presence of L. mediterraneus from both the Mediterranean and Atlantic coast and L. cephali and L. maroccanus sp. n. from the Atlantic coast only. The latter species, which is described herein as new, resembles L. guanduensis but differs from this species mainly in having a shorter penis compared to the accessory piece, a proportionally longer extremity of the accessory piece and a less developed heel. The utility of Ligophorus spp. as markers of cryptic species of the complex M. cephalus is discussed in the context of species diversity and geographical distribution of these monogeneans on this host around the world. Presence of different species of Ligophorus on M. cephalus sensu stricto from the Atlantic and Mediterranean coast of Morocco demonstrates the usefulness of these species as fine resolution markers of genetic populations of their host, which are known to inhabit those coasts.

  11. Plant Host Species and Geographic Distance Affect the Structure of Aboveground Fungal Symbiont Communities, and Environmental Filtering Affects Belowground Communities in a Coastal Dune Ecosystem. (United States)

    David, Aaron S; Seabloom, Eric W; May, Georgiana


    Microbial symbionts inhabit tissues of all plants and animals. Their community composition depends largely on two ecological processes: (1) filtering by abiotic conditions and host species determining the environments that symbionts are able to colonize and (2) dispersal-limitation determining the pool of symbionts available to colonize a given host and community spatial structure. In plants, the above- and belowground tissues represent such distinct habitats for symbionts that we expect different effects of filtering and spatial structuring on their symbiont communities. In this study, we characterized above- and belowground communities of fungal endophytes--fungi living asymptomatically within plants--to understand the contributions of filtering and spatial structure to endophyte community composition. We used a culture-based approach to characterize endophytes growing in leaves and roots of three species of coastal beachgrasses in dunes of the USA Pacific Northwest. For leaves, endophyte isolation frequency and OTU richness depended primarily on plant host species. In comparison, for roots, both isolation frequency and OTU richness increased from the nutrient-poor front of the dune to the higher-nutrient backdune. Endophyte community composition in leaves exhibited a distance-decay relationship across the region. In a laboratory assay, faster growth rates and lower spore production were more often associated with leaf- than root-inhabiting endophytes. Overall, our results reveal a greater importance of biotic filtering by host species and dispersal-limitation over regional geographic distances for aboveground leaf endophyte communities and stronger effects of abiotic environmental filtering and locally patchy distributions for belowground root endophyte communities.

  12. Metabolomic analysis reveals a common pattern of metabolic re-programming during invasion of three host plant species by Magnaporthe grisea. (United States)

    Parker, David; Beckmann, Manfred; Zubair, Hassan; Enot, David P; Caracuel-Rios, Zaira; Overy, David P; Snowdon, Stuart; Talbot, Nicholas J; Draper, John


    The mechanisms by which biotrophic and hemi-biotrophic fungal pathogens simultaneously subdue plant defences and sequester host nutrients are poorly understood. Using metabolite fingerprinting, we show that Magnaporthe grisea, the causal agent of rice blast disease, dynamically re-programmes host metabolism during plant colonization. Identical patterns of metabolic change occurred during M. grisea infections in barley, rice and Brachypodium distachyon. Targeted metabolite profiling by GC-MS confirmed the modulation of a conserved set of metabolites. In pre-symptomatic tissues, malate and polyamines accumulated, rather than being utilized to generate defensive reactive oxygen species, and the levels of metabolites associated with amelioration of redox stress in various cellular compartments increased dramatically. The activity of NADP-malic enzyme and generation of reactive oxygen species were localized to pathogen penetration sites, and both appeared to be suppressed in compatible interactions. Early diversion of the shikimate pathway to produce quinate was observed, as well as accumulation of non-polymerized lignin precursors. These data are consistent with modulation of defensive phenylpropanoid metabolism by M. grisea and the inability of susceptible hosts to mount a hypersensitive reaction or produce lignified papillae (both involving reactive oxygen species) to restrict pathogen invasion. Rapid proliferation of M. grisea hyphae in plant tissue after 3 days was associated with accelerated nutrient acquisition and utilization by the pathogen. Conversion of photoassimilate into mannitol and glycerol for carbon sequestration and osmolyte production appear to drive hyphal growth. Taken together, our results suggest that fungal pathogens deploy a common metabolic re-programming strategy in diverse host species to suppress plant defence and colonize plant tissue.

  13. Description of the immature stages and new host plant records of Deois (Deois) mourei (Berg) (Hemiptera: Cercopidae), a species newly recorded from Argentina and Paraguay. (United States)

    Foieri, Alvaro; Lenicov, Ana M Marino De Remes; Virla, Eduardo G


    Deois (Deois) mourei Cavichioli & Sakakibara (Hemiptera: Cercopidae) is recorded for the first time from Argentina and Paraguay. The eggs and immature stages of the species are described and illustrated; the main characters that distinguish instars are body size, color, number of flagellomeres, and number of tibial and metatarsomere spines. A key for identification of nymphs of D. (D.) mourei and a key to differentiate nymphs of the sympatric species D. (D.) mourei and Notozulia entreriana Berg are provided. In addition, a list of host plants of D. (D.) mourei in Argentina is given.

  14. The abundance and host-seeking behavior of culicine species (Diptera: Culicidae and Anopheles sinensis in Yongcheng city, people's Republic of China

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    Liu Xiao-Bo


    Full Text Available Abstract Background The knowledge of mosquito species diversity and the level of anthropophily exhibited by each species in a region are of great importance to the integrated vector control. Culicine species are the primary vectors of Japanese encephalitis (JE virus and filariasis in China. Anopheles sinensis plays a major role in the maintenance of Plasmodium vivax malaria transmission in China. The goal of this study was to compare the abundance and host-seeking behavior of culicine species and An. sinensis in Yongcheng city, a representative region of P. vivax malaria. Specifically, we wished to determine the relative attractiveness of different animal baits versus human bait to culicine species and An. sinensis. Results Culex tritaeniorhynchus was the most prevalent mosquito species and An. sinensis was the sole potential vector of P. vivax malaria in Yongcheng city. There were significant differences (P An. sinensis and Cx. tritaeniorhynchus collected in distinct baited traps. The relative attractiveness of animal versus human bait was similar towards both An. sinensis and Cx. tritaeniorhynchus. The ranking derived from the mean number of mosquitoes per bait indicated that pigs, goats and calves frequently attracted more mosquitoes than the other hosts tested (dogs, humans, and chickens. These trends were similar across all capture nights at three distinct villages. The human blood index (HBI of female An. sinensis was 2.94% when computed with mixed meals while 3.70% computed with only the single meal. 19:00~21:00 was the primary peak of host-seeking female An. sinensis while 4:00~5:00 was the smaller peak at night. There was significant correlation between the density of female An. sinensis and the average relative humidity (P Conclusions Pigs, goats and calves were more attractive to An. sinensis and Cx. tritaeniorhynchus than dogs, humans, and chickens. Female An. sinensis host-seeking activity mainly occurred from 19:00 to 21:00. Thus

  15. Analysis of multi-strain Bartonella pathogens in natural host population--do they behave as species or minor genetic variants? (United States)

    Chan, Kung-Sik; Kosoy, Michael


    Modern advances in genetic analysis have made it feasible to ascertain the variant type of a pathogen infecting a host. Classification of pathogen variants is commonly performed by clustering analysis of the observed genetic divergence among the variants. A natural question arises whether the genetically distinct variants are epidemiologically distinct. A broader question is whether the different variants constitute separate microbial species or represent minor variations of the same species. These important issues were addressed in the context of analyzing dynamics of genetically distinct variants of Bartonella bacteria in cotton rat hosts. Frequencies of acquiring a new variant were measured in relation to the genetic differences between variants successively infecting an individual rodent host. Two statistical techniques were introduced for performing such analysis, and the methodologies were illustrated with a set of data collected from a particular multi-strain Bartonella system. We carried out a frequency analysis of co-infection patterns, and a Markov chain analysis of panels of successive mixed infection time series for testing some particular gene-based grouping of the Bartonella variants with a panel of observed disease data from a rodent population. Our analysis suggests that the three genogroups A, B and C of Bartonella function as independent species but the variants within each genogroup enjoy some cross-immunity against each other. The newly developed methodologies are broadly applicable for analyzing other multi-strain pathogen data which are increasingly collected for diverse infectious diseases.

  16. Genetic characterization of oropharyngeal trichomonad isolates from wild birds indicates that genotype is associated with host species, diet and presence of pathognomonic lesions. (United States)

    Martínez-Herrero, M C; Sansano-Maestre, J; López Márquez, I; Obón, E; Ponce, C; González, J; Garijo-Toledo, M M; Gómez-Muñoz, M T


    Oropharyngeal trichomonad isolates of wild birds from Spain were studied. A total of 1688 samples (1214 of predator birds and 474 of prey species) from wildlife recovery centres and scientific bird-ringing campaigns were analysed from 2011 to 2013. The overall infection prevalence was 20.3% (11.4% in predator birds and 43.3% in prey species). Pathognomonic lesions were present in 26% of the infected birds (57.3% in predator birds and 4.9% in prey species). The most commonly parasitized species were the goshawk (Accipiter gentilis, 74.5%) and the rock pigeon (Columba livia, 79.4%). Host species in which the parasite has not been previously analysed by polymerase chain reaction and sequencing in Spain are also reported: Columba palumbus, Streptopelia turtur, Pica pica, A. gentilis, Accipiter nisus, Asio otus, Bubo bubo, Buteo buteo, Circus aeruginosus, Circus cyaneus, Falco naumanni, Falco peregrinus, Neophron percnopterus, Otus scops, Pernis apivorus and Strix aluco. Sequence analysis of the ITS1/5.8S/ITS2 region revealed five different genotypes and also some mixed infections. A relationship between genotype and host species was observed, but only two genotypes (ITS-OBT-Tg-1and ITS-OBT-Tg-2) were widely distributed. Genotype ITS-OBT-Tg-1 was most frequently found in predator birds and statistically associated with pathognomonic lesions. Non-strict ornithophagous species were at higher risk to develop disease than ornithophagous ones. Genotypes ITS-OBT-Tcl-1 and ITS-OBT-Tcl-2 are new reports, and ITS-OBT-Tvl-5 is reported for the first time in Spain. They showed higher genetic homology to Trichomonas canistomae and Trichomonas vaginalis than to Trichomonas gallinae, indicating the possibility of new species within this genus.

  17. The Fleas of Endemic and Introduced Small Mammals in Central Highland Forests of Madagascar: Faunistics, Species Diversity, and Absence of Host Specificity. (United States)

    Goodman, Steven M; Randrenjarison Andriniaina, H Rico; Soarimalala, Voahangy; Beaucournu, Jean-Claude


    Data are presented on the flea species of the genera Paractenopsyllus (Ceratophyllidae, Leptopsyllinae) and Synopsyllus (Pulicidae, Xenopsyllinae) obtained from small mammals during two 2014 seasonal surveys at a montane humid forest site (Ambohitantely) in the Central Highlands of Madagascar. The mammal groups included the endemic family Tenrecidae (tenrecs) and subfamily Nesomyinae (rodents) and two introduced families Muridae (rodents) and Soricidae (shrews); no fleas were recovered from the latter family. The surveys were conducted at the end of the wet and dry seasons with 288 individual small mammals captured, including 12 endemic and four introduced species. These animals yielded 344 fleas, representing nine species endemic to Madagascar; no introduced species was collected. Some seasonal variation was found in the number of trapped small mammals, but no marked difference was found in species richness. For flea species represented by sufficient samples, no parasite-host specificity was found, and there is evidence for considerable lateral exchange in the local flea fauna between species of tenrecs and the two rodent families (endemic and introduced). The implications of these results are discussed with regards to small mammal species richness and community structure, as well as a possible mechanism for the maintenance of sylvatic cycles of bubonic plague in the montane forests of Madagascar.

  18. Response of brown-headed cowbirds and three host species to thinning treatments in low-elevation ponderosa pine forests along the northern Colorado Front Range (United States)

    Keeley, W.H.; Germaine, Stephen S.; Stanley, Thomas R.; Spaulding, Sarah A.; Wanner, C.E.


    Thinning ponderosa pine (Pinus ponderosa) forests to achieve desired ecological conditions remains a priority in the North American west. In addition to reducing the risk of high-severity wildfires in unwanted areas, stand thinning may increase wildlife and plant diversity and provide increased opportunity for seedling recruitment. We initiated conservative (i.e. minimal removal of trees) ponderosa stand thinning treatments with the goals of reducing fire risk and improving habitat conditions for native wildlife and flora. We then compared site occupancy of brown-headed cowbirds (Molothrus ater), chipping sparrows (Spizella passerina), plumbeous vireos (Vireo plumbeus), and western wood-pewees (Contopus sordidulus) in thinned and unthinned (i.e., control) forest stands from 2007 to 2009. Survey stations located in thinned stands had 64% fewer trees/ha, 25% less canopy cover, and 23% less basal area than stations in control stands. Occupancy by all three host species was negatively associated with tree density, suggesting that these species respond favorably to forest thinning treatments in ponderosa pine forests. We also encountered plumbeous vireos more frequently in plots closer to an ecotonal (forest/grassland) edge, an association that may increase their susceptibility to edge-specialist, brood parasites like brown-headed cowbirds. Occupancy of brown-headed cowbirds was not related to forest metrics but was related to occupancy by plumbeous vireos and the other host species in aggregate, supporting previous reports on the affiliation between these species. Forest management practices that promote heterogeneity in forest stand structure may benefit songbird populations in our area, but these treatments may also confer costs associated with increased cowbird occupancy. Further research is required to understand more on the complex relationships between occupancy of cowbirds and host species, and between cowbird occupancy and realized rates of nest parasitism.

  19. A new feather mite species of the genus Neumannella Trouessart, 1916 (Analgoidea, Dermoglyphidae) from the Red-winged Tinamou Rhynchotus rufescens (Temminck, 1815) (Aves, Tinamiformes) with remarks to the evolution of host-parasite associations of the genus. (United States)

    Dabert, Jacek


    Neumannella skorackii, a new species of the feather mite family Dermoglyphidae (Acari, Astigmata) is described from the Red-winged Tinamou Rhynchotus rufescens (Temminck, 1815) (Aves, Tinamiformes) from Paraguay and a key to all known species of the genus is provided. The phylogenetic relationships (MP analysis of 25 morphological characters) between Neumannella species along with the evolutionary history of host-parasite associations revealed by Jungle reconciliation method are reconstructed. Relatively low cospeciation contribution to the recent host-parasite associations is discovered.

  20. Study on the Major Host Plant Species of Lac Insect, Wax Scale and Gall Aphids%紫胶虫、白蜡虫、倍蚜虫主要寄主 植物种类研究

    Institute of Scientific and Technical Information of China (English)

    陈玉培; 李文良


    Lac insect, wax scale and gall aphids are the important resource insect s in China. Host plant is not only the habitant and reproductive sites for resou rce insects but also their food resource. The species of host plant are various, and some of them are excellent hosts. The host plant species were extensively c ollected from the major production regions of lac, wax and Chinese gallnut, and then reproduced in Jingdong of Yunnan where locates in the southern subtropical region. It has been conserved in the Arboretum of Jingdong Trial Station by Ex-situ con servation. More than 200 species, which belong to 98 genuses,36 families of host plant of lac insect, wax scale and gall aphids have been collected over many ye ars. These species are valuable materials available for studying these resource insects and their host plant. From these species, it is possible to develop exce llent hosts that can be put into use in production. Also these species is the ba sic materials to be used in host plant breeding and enhancement and research on their multiple utility. The study was conducted during the period of 1993~1999, and its major results are reported.

  1. Duration of plant damage by host larvae affects attraction of two parasitoid species (Microplitis croceipes and Cotesia marginiventris) to cotton: implications for interspecific competition. (United States)

    Morawo, Tolulope; Fadamiro, Henry


    Volatile organic compounds (VOCs) released by herbivore-damaged plants can guide parasitoids to their hosts. The quantity and quality of VOC blends emitted by plants may be affected by the duration of plant damage by herbivores, which could have potential ramifications on the recruitment of competing parasitoids. We used two parasitoid species, Microplitis croceipes and Cotesia marginiventris (Hymenoptera: Braconidae), to address the question of whether duration of plant damage affects parasitoid use of plant VOCs for host location. Both wasp species are larval endoparasitoids of Heliothis virescens (Lepidoptera: Noctuidae), an important pest of cotton. Attraction of the two parasitoid species to odors emitted by undamaged (UD), fresh (6 h infestation) damage (FD), and old (24 h infestation) damage (OD) cotton plants infested by H. virescens larvae was investigated using a headspace volatile collection system coupled with four-choice olfactometer bioassay. Both sexes of M. croceipes showed a preference for FD- and OD-plant odors over UD-plants. On the other hand, more C. marginiventris females were attracted to UD- and FD-plants than to OD-plants. GC/MS analyses showed qualitative and quantitative differences in the VOC profiles of UD, FD, and OD-plants, which may explain the observed preferences of the parasitoids. These results suggest a temporal partitioning in the recruitment of M. croceipes and C. marginiventris to H. virescens-damaged cotton, and may have potential implications for interspecific competition between the two parasitoid species.

  2. A plasmid RK2-based broad-host-range cloning vector useful for transfer of metagenomic libraries to a variety of bacterial species. (United States)

    Aakvik, Trine; Degnes, Kristin Fløgstad; Dahlsrud, Rannveig; Schmidt, Frank; Dam, Ragnar; Yu, Lihua; Völker, Uwe; Ellingsen, Trond Erling; Valla, Svein


    The majority of microorganisms in natural environments are difficult to cultivate, but their genes can be studied via metagenome libraries. To enhance the chances that these genes become expressed we here report the construction of a broad-host-range plasmid vector (pRS44) for fosmid and bacterial artificial chromosome (BAC) cloning. pRS44 can be efficiently transferred to numerous hosts by conjugation. It replicates in such hosts via the plasmid RK2 origin of replication, while in Escherichia coli it replicates via the plasmid F origin. The vector was found to be remarkably stable due to the insertion of an additional stability element (parDE). The copy number of pRS44 is adjustable, allowing for easy modifications of gene expression levels. A fosmid metagenomic library consisting of 20 000 clones and BAC clones with insert sizes up to 200 kb were constructed. The 16S rRNA gene analysis of the fosmid library DNA confirmed that it represents a variety of microbial species. The entire fosmid library and the selected BAC clones were transferred to Pseudomonas fluorescens and Xanthomonas campestris (fosmids only), and heterologous proteins from the fosmid library were confirmed to be expressed in P. fluorescens. To our knowledge no other reported vector system has a comparable potential for functional screening across species barriers.

  3. On some Indo-Pacific boring endolithic Bivalvia species introduced into the Mediterranean Sea with their host – spread of Sphenia rueppelli A. Adams, 1850

    Directory of Open Access Journals (Sweden)



    Full Text Available The study of the endolithic molluscs found on/in living alien Spondylusshells collected in the Gulf of Iskenderun (Turkey brought to light three more alien bivalvia species namely Petricola hemprichi, Gastrochaena cymbium and Sphenia rueppelli. The presence of Sphenia rueppellideserves attention as it constitutes the first record of this species as living in the Mediterranean Sea. The definitive establishment and spreading of these bivalves in the basin seems to be also attested by careful analysis of specimens sampled in other southern Turkish localities and previously retained in local private collections. The present records raise some questions on the vector of arrival of the species in the Mediterranean Sea that could be strictly connected with their hosts.

  4. Dialeurolonga re-defined (Hemiptera: Aleyrodidae): with a new genus and species from India, two new genera from Australia, and discussion of host-correlated puparial variation. (United States)

    Dubey, Anil Kumar; Ramamurthy, V V


    Aleuropositus Dubey gen. n., Australeurodes Dubey gen. n. and Septemaleurodes Dubey gen. n. are proposed with their respective type species as A. sinus Dubey sp. n. from India, D. operculobata Martin & Carver from Australia, and D. swainei Martin from Australia. A. sinus sp. n. is described from Kerala, India, illustrated with line drawings, microphotographs and SEM images. The puparia are asymmetric in taxonomic characters and shape, and variation in puparia associated with a single host is discussed. A generic diagnosis of Dialeurolonga is provided based on SEM study of the type species, D. elongata. Australian species placed in this genus have puparial characteristics that distinguish them from Afrotropical assemblages, and are here referred to two new genera.

  5. Complete Genome sequence of Burkholderia phymatum STM815T, a broad host range and efficient nitrogen-fixing symbiont of Mimosa species (United States)

    Moulin, Lionel; Klonowska, Agnieszka; Caroline, Bournaud; Booth, Kristina; Vriezen, Jan A.C.; Melkonian, Rémy; James, Euan K.; Young, J. Peter W.; Bena, Gilles; Hauser, Loren; Land, Miriam; Kyrpides, Nikos; Bruce, David; Chain, Patrick; Copeland, Alex; Pitluck, Sam; Woyke, Tanja; Lizotte-Waniewski, Michelle; Bristow, Jim; Riley, Margaret


    Burkholderia phymatum is a soil bacterium able to develop a nitrogen-fixing symbiosis with species of the legume genus Mimosa, and is frequently found associated specifically with Mimosa pudica. The type strain of the species, STM 815T, was isolated from a root nodule in French Guiana in 2000. The strain is an aerobic, motile, non-spore forming, Gram-negative rod, and is a highly competitive strain for nodulation compared to other Mimosa symbionts, as it also nodulates a broad range of other legume genera and species. The 8,676,562 bp genome is composed of two chromosomes (3,479,187 and 2,697,374 bp), a megaplasmid (1,904,893 bp) and a plasmid hosting the symbiotic functions (595,108 bp). PMID:25197461

  6. Complete Genome sequence of Burkholderia phymatum STM815, a broad host range and efficient nitrogen-fixing symbiont of Mimosa species

    Energy Technology Data Exchange (ETDEWEB)

    Moulin, Lionel [UMR, France; Klonowska, Agnieszka [UMR, France; Caroline, Bournaud [UMR, France; Booth, Kristina [University of Massachusetts; Vriezen, Jan A.C. [University of Massachusetts; Melkonian, Remy [UMR, France; James, Euan [James Hutton Institute, Dundee, United Kingdom; Young, Peter W. [University of York, United Kingdom; Bena, Gilles [UMR, France; Hauser, Loren John [ORNL; Land, Miriam L [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Copeland, A [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Lizotte-Waniewski, Michelle [University of Massachusetts; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Riley, Monica [Woods Hole Oceanographic Institution (WHOI), Woods Hole


    Burkholderia phymatum is a soil bacterium able to develop a nitrogen-fixing symbiosis with species of the legume genus Mimosa, and is frequently found associated specifically with Mimosa pudica. The type strain of the species, STM 815T, was isolated from a root nodule in French Guiana in 2000. The strain is an aerobic, motile, non-spore forming, Gram-negative rod, and is a highly competitive strain for nodulation compared to other Mimosa symbionts, as it also nodulates a broad range of other legume genera and species. The 8,676,562 bp genome is composed of two chromosomes (3,479,187 and 2,697,374 bp), a megaplasmid (1,904,893 bp) and a plasmid hosting the symbiotic functions (595,108 bp).

  7. Complete Genome sequence of Burkholderia phymatum STM815(T), a broad host range and efficient nitrogen-fixing symbiont of Mimosa species. (United States)

    Moulin, Lionel; Klonowska, Agnieszka; Caroline, Bournaud; Booth, Kristina; Vriezen, Jan A C; Melkonian, Rémy; James, Euan K; Young, J Peter W; Bena, Gilles; Hauser, Loren; Land, Miriam; Kyrpides, Nikos; Bruce, David; Chain, Patrick; Copeland, Alex; Pitluck, Sam; Woyke, Tanja; Lizotte-Waniewski, Michelle; Bristow, Jim; Riley, Margaret


    Burkholderia phymatum is a soil bacterium able to develop a nitrogen-fixing symbiosis with species of the legume genus Mimosa, and is frequently found associated specifically with Mimosa pudica. The type strain of the species, STM 815(T), was isolated from a root nodule in French Guiana in 2000. The strain is an aerobic, motile, non-spore forming, Gram-negative rod, and is a highly competitive strain for nodulation compared to other Mimosa symbionts, as it also nodulates a broad range of other legume genera and species. The 8,676,562 bp genome is composed of two chromosomes (3,479,187 and 2,697,374 bp), a megaplasmid (1,904,893 bp) and a plasmid hosting the symbiotic functions (595,108 bp).

  8. Cryptic speciation and host specificity among Mycosphaerella spp. occurring on Australian Acacia species grown as exotics in the tropics

    NARCIS (Netherlands)

    Crous, P.W.; Groenewald, J.Z.; Pongpanich, K.; Himaman, W.; Arzanlou, M.; Wingfield, M.J.


    Species of Mycosphaerella and their anamorphs represent serious pathogens of two phyllodenous species of Acacia, A. mangium and A. crassicarpa. In recent years, these fungi have been collected during surveys in South America and South-East Asia, where these trees are widely planted as exotics. In

  9. Cryptic speciation and host specificity among Mycosphaerella spp. occurring on Australian Acacia species grown as exotics in the tropics

    NARCIS (Netherlands)

    Crous, P.W.; Groenewald, J.Z.; Pongpanich, K.; Himaman, W.; Arzanlou, M.; Wingfield, M.J.


    Species of Mycosphaerella and their anamorphs represent serious pathogens of two phyllodenous species of Acacia, A. mangium and A. crassicarpa. In recent years, these fungi have been collected during surveys in South America and South-East Asia, where these trees are widely planted as exotics. In th

  10. Osmia species (Hymenoptera, Megachilidae) from the southeastern United States with modified facial hairs: taxonomy, host plants, and conservation status (United States)

    We describe females and males of Osmia (Melanosmia) calaminthae, new species, an apparent floral specialist on Calamintha ashei (Lamiaceae). Females of O. calaminthae have short, erect, simple facial hairs. The species is currently only known from sandy scrub at a number of sites in the southern La...

  11. Behavioral analysis of Microphallus turgidus cercariae in relation to microhabitat of two host grass shrimp species (Palaemonetes spp.). (United States)

    O'Leary, Patricia A; Pung, Oscar J


    The behavior of Microphallus turgidus cercariae was examined and compared to microhabitat selection of the second intermediate hosts of the parasite, Palaemonetes spp. grass shrimp. Cercariae were tested for photokinetic and geotactic responses, and a behavioral ethogram was established for cercariae in control and grass shrimp-conditioned brackish water. Photokinesis trials were performed using a half-covered Petri dish, and geotaxis trials used a graduated cylinder. Both photokinesis and geotaxis trials were performed in lighted and unlighted conditions. In 9 of 10 photokinesis experiments, over half of the cercariae swam horizontally under the covered half of a Petri dish in both the lighted and the unlighted trials. However, movement of the cercariae to the covered half of the dish was highest (81.4%) when the parasites were exposed to light. In the geotaxis study, most cercariae were found in the bottom third of a graduated cylinder water column in both the lighted and unlighted trials. The most frequently observed activity of individual cercariae in a lighted Petri dish was swimming on the bottom of the dish. Activity patterns of the cercariae were not affected by shrimp-conditioned water. Movement of the cercariae away from light into dark, active swimming at or near the bottom of the water column, and a lack of response to host odors suggest that the cercariae utilize search patterns that place the parasite in the preferred microhabitat of the principle second intermediate host, the grass shrimp P. pugio.

  12. Host islands within the California Northern Channel Islands create fine-scale genetic structure in two sympatric species of the symbiotic ectomycorrhizal fungus Rhizopogon. (United States)

    Grubisha, Lisa C; Bergemann, Sarah E; Bruns, Thomas D


    We have examined fine-scale genetic structure of the symbiotic ectomycorrhizal fungi Rhizopogon occidentalis and R. vulgaris on two of the California Channel Islands using five and six microsatellite loci, respectively. Both Rhizopogon species are sympatric on Santa Cruz and Santa Rosa Islands and are ectomycorrhizal with bishop pine (Pinus muricata) on both islands or Santa Rosa Island Torrey pine (P. torreyana ssp. insularis) on Santa Rosa. The combination of disjunct pine host distributions and geographic barriers within and among the islands have created highly structured Rhizopogon populations over very short distances (8.5 km on Santa Cruz Island; F(ST) = 0.258, F(ST) = 0.056, R. occidentalis and R. vulgaris, respectively). Both species show similar patterns of genetic differentiation as a result of limited dispersal between host populations as revealed by a significant isolation by distance relationship (r = 0.69, P analyses, and is most likely a function of the small foraging range of the few mammals that disperse Rhizopogon on these islands and the enormous spore bank characteristic of Rhizopogon species.


    Directory of Open Access Journals (Sweden)

    Daniela Barbuceanu


    Full Text Available Observations carried out in May-September 2015 in two sites of Southern Romania reveal a rich spectrum of host plants for Metcalfa pruinosa, which consists of 204 species in 56 families. The species it is noticed on weeds and cultivated plants. The remarkable polyphagia of this species, the lack of natural enemies, and the climatic conditions of 2015 - warm and dry summer, had lead to an invasion of M. pruinosa, in the researched areas; the highest numerical abundances are noticed in shady habitats. Furthermore, on herbs, such as Levisticum officinale, Artemisia dracunculus, Ocimum basilicum, Mentha spp., usually avoided by pests, were observed colonies of the species. It is recorded high numerical abundance on fruit trees and shrubs: Hippophaë rhamnoides, Juglans regia, Prunus cerasus, Vitis vinifera, Rubus idaeus. The harmful effect occurs on apple trees Romus 1 variety as a result of the association with another pest of American origin, Eriosoma lanigerum, situation that favors the attack of the Erwinia amylovora bacteria, causing the collapse of the tree. It is found that altitudes higher than 200 m do not represent a limitative factor in the spreading of species, one of the investigated sites being located at 304 m altitude.

  14. A key to American genus Merobruchus Bridwell (Coleoptera: Chrysomelidae: Bruchinae) with descriptions of species and two new host plant records for the subfamily. (United States)

    Manfio, Daiara; Ribeiro-Costa, Cibele Stramare


    Merobruchus Bridwell is placed in the group Merobruchus of Acanthoscelidina (Bruchini) being distinguished from all bruchines mainly by the apical projections in the last abdominal ventrite of females and some males. All 25 species of Merobruchus are distributed in the New World, mainly in the Neotropical Region, feeding on seeds of Mimosoideae (Acacieae, Ingeae and Mimoseae). As well as some other bruchine genera, Merobruchus shows considerable morphological variation both in external and in internal (male genitalia) characters. Moreover, some species are very similar to each other in their colour and distribution pattern of pubescence on the dorsal surface, sometimes making species recognition difficult. Thus, the main objective of this paper is to provide a key including coloured illustrations for Merobruchus species to facilitate the process of identification and to avoid misunderstandings. Images of dorsal habitus, male and female pygidium and male genitalia are provided for all species. In addition, M. machadoi sp. nov. (Holotype male deposited in DZUP: Brazil, Rio Grande do Sul State) is described; M. bicoloripes (Pic) and M. pickeli (Pic) are redescribed; and a new synonymy is proposed: Pseudopachymerus pickeli Pic, 1927 = Pseudopachymerus pickeli var. subnotatus Pic, 1927 syn. nov. Two new host plants are recorded for Bruchinae: Parapiptadenia rigida (Benth.) Brenan (Mimosoideae) and Pterogyne nitens Tul. (Caesalpinioideae).

  15. Key to Holarctic species of Epitrix flea beetles (Coleoptera: Chrysomelidae: Galerucinae: Alticini) with review of their distribution, host plants and history of invasions. (United States)

    Bieńkowski, Andrzej O; Orlova-Bienkowskaja, Marina J


    The genus Epitrix Foudras, 1860a has a worldwide distribution. Some species of Epitrix are major pests of potato, tomato, eggplant, tobacco and other plants in North America and Europe. Some pest species have been inadvertently introduced from North America to Europe, from Europe to North America and from both continents to some islands in Atlantic and Pacific oceans. Therefore, a key for the identification of all Holarctic species is necessary for plant quarantine and protection services. We have compiled the key for distinguishing Epitrix from genera that could be confused with it and a key for all Holarctic species of Epitrix with the figures of spermathecae and aedeagi and the checklist with a review of the geographical distribution, host plants and history of invasions. The following species are included: E. abeillei (Bauduer), E. allardii (Wollaston), E. atropae Foudras, E. brevis Schwarz, E. caucasica (Heikertinger), E. cucumeris (Harris), E. dieckmanni (Mohr), E. ermischi (Mohr), E. fasciata Blatchley, E. flavotestacea Horn, E. fuscula Crotch, E. hirtipennis (Melsheimer), E. humeralis Dury, E. intermedia Foudras, E. krali Döberl, E. lobata Crotch, E. muehlei Döberl, E. priesneri (Heikertinger), E. pubescens (Koch), E. ogloblini (Iablokov-Khnzorian), E. robusta Jacoby, E. setosella (Fairmaire), E. similaris Gentner, E. solani (Blatchley), E. subcrinita (LeConte), E. tuberis Gentner, E. warchalowskii (Mohr) and E. papa Orlova-Bienkowskaja.

  16. Species-specific interactions between algal endosymbionts and coral hosts define their bleaching response to heat and light stress

    DEFF Research Database (Denmark)

    Abrego, David; Ulstrup, Karin E; Willis, Bette L


    The impacts of warming seas on the frequency and severity of bleaching events are well documented, but the potential for different Symbiodinium types to enhance the physiological tolerance of reef corals is not well understood. Here we compare the functionality and physiological properties...... and a potential role for host factors in determining the physiological performance of reef corals....... of juvenile corals when experimentally infected with one of two homologous Symbiodinium types and exposed to combined heat and light stress. A suite of physiological indicators including chlorophyll a fluorescence, oxygen production and respiration, as well as pigment concentration consistently demonstrated...

  17. Can other host species of cotton bollworm be non-Bt refuges to prolong the effectiveness of Bt-cotton?

    Institute of Scientific and Technical Information of China (English)


    The potential ecological risks of Bacillus thurigiensis (Bt) insecticides and Bt-crops have caused increasing concern since their commercial release in the field,among which pests' resistance to Bt-crops is the major ecological risk. Refuge tactic, which can produce sensitive populations, has proved to be a key and sound resistance management strategy in USA and Australia; however, no tactics have been performed in China where Bt-cotton is mostly planted with other host crops of cotton bollworm.Genetic variation and gene flow among different host populations of the cotton bollworm Helicoverpa armigera were analyzed using PCR fingerprinting method. The results show that maize and castor-oil plant, as well as cotton can take effect as refuges to prevent resistance of cotton bollworm to Bt-cotton, while peanut and sesame are not as suitable for planting with Bt-cotton as refuges in the field as low gene flow was detected among populations on peanut, sesame and Bt cotton.

  18. Native bacterial endophytes promote host growth in a species-specific manner; phytohormone manipulations do not result in common growth responses.

    Directory of Open Access Journals (Sweden)

    Hoang Hoa Long

    Full Text Available BACKGROUND: All plants in nature harbor a diverse community of endophytic bacteria which can positively affect host plant growth. Changes in plant growth frequently reflect alterations in phytohormone homoeostasis by plant-growth-promoting (PGP rhizobacteria which can decrease ethylene (ET levels enzymatically by 1-aminocyclopropane-1-carboxylate (ACC deaminase or produce indole acetic acid (IAA. Whether these common PGP mechanisms work similarly for different plant species has not been rigorously tested. METHODOLOGY/PRINCIPAL FINDINGS: We isolated bacterial endophytes from field-grown Solanum nigrum; characterized PGP traits (ACC deaminase activity, IAA production, phosphate solubilization and seedling colonization; and determined their effects on their host, S. nigrum, as well as on another Solanaceous native plant, Nicotiana attenuata. In S. nigrum, a majority of isolates that promoted root growth were associated with ACC deaminase activity and IAA production. However, in N. attenuata, IAA but not ACC deaminase activity was associated with root growth. Inoculating N. attenuata and S. nigrum with known PGP bacteria from a culture collection (DSMZ reinforced the conclusion that the PGP effects are not highly conserved. CONCLUSIONS/SIGNIFICANCE: We conclude that natural endophytic bacteria with PGP traits do not have general and predictable effects on the growth and fitness of all host plants, although the underlying mechanisms are conserved.

  19. Occurrence of Mycobacterium avium subspecies paratuberculosis across host species and European countries with evidence for transmission between wildlife and domestic ruminants

    Directory of Open Access Journals (Sweden)

    May Linda


    Full Text Available Abstract Background Mycobacterium avium subspecies paratuberculosis (Map causes an infectious chronic enteritis (paratuberculosis or Johne's disease principally of ruminants. The epidemiology of Map is poorly understood, particularly with respect to the role of wildlife reservoirs and the controversial issue of zoonotic potential (Crohn's disease. Genotypic discrimination of Map isolates is pivotal to descriptive epidemiology and resolving these issues. This study was undertaken to determine the genetic diversity of Map, enhance our understanding of the host range and distribution and assess the potential for interspecies transmission. Results 164 Map isolates from seven European countries representing 19 different host species were genotyped by standardized IS900 - restriction fragment length polymorphism (IS900-RFLP, pulsed-field gel electrophoresis (PFGE, amplified fragment length polymorphisms (AFLP and mycobacterial interspersed repeat unit-variable number tandem repeat (MIRU-VNTR analyses. Six PstI and 17 BstEII IS900-RFLP, 31 multiplex [SnaBI-SpeI] PFGE profiles and 23 MIRU-VNTR profiles were detected. AFLP gave insufficient discrimination of isolates for meaningful genetic analysis. Point estimates for Simpson's index of diversity calculated for the individual typing techniques were in the range of 0.636 to 0.664 but a combination of all three methods increased the discriminating power to 0.879, sufficient for investigating transmission dynamics. Two predominant strain types were detected across Europe with all three typing techniques. Evidence for interspecies transmission between wildlife and domestic ruminants on the same property was demonstrated in four cases, between wildlife species on the same property in two cases and between different species of domestic livestock on one property. Conclusion The results of this study showed that it is necessary to use multiple genotyping techniques targeting different sources of genetic

  20. Prevalence of viral haemorrhagic septicaemia virus in Danish marine fishes and its occurrence in new host species

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Olesen, Niels Jørgen; Mellergaard, Stig


    In order to analyse the occurrence of viral haemorrhagic septicaerma virus (VHSV) in the marine waters around Denmark, staff from the Danish Institute for Food and Veterinary Research participated in 5 research cruises during 1998 to 2002 as a follow-up to 4 research cruises performed in 1996...... to 1997. In total, 16 655 fish were examined virologically as 3569 samples. Forty fish species and 3 invertebrate species were represented. VHSV was isolated from 133 samples representing 8 species: herring Clupea harengus, sprat Sprattus sprattus, dab Limanda limanda, flounder Platichthys flesus, plaice...... Pleuronectes platessa, cod Gadus morhua, sand eel Ammodytes sp. and sand goby Pomatochistus minutus. Calculations showed that VHSV was more prevalent in the Baltic Sea in an area between Zealand and the island of Bornholm and the waters surrounding Bornholm than in the Kattegat, Skagerrak and along the North...

  1. Comparative Evaluation of DNA Extraction Methods from Feces of Multiple Host Species for Downstream Next-Generation Sequencing. (United States)

    Hart, Marcia L; Meyer, Alexandra; Johnson, Philip J; Ericsson, Aaron C


    The gastrointestinal tract contains a vast community of microbes that to this day remain largely unculturable, making studies in this area challenging. With the newly affordable advanced sequencing technology, important breakthroughs in this exciting field are now possible. However, standardized methods of sample collection, handling, and DNA extraction have yet to be determined. To help address this, we investigated the use of 5 common DNA extraction methods on fecal samples from 5 different species. Our data show that the method of DNA extraction impacts DNA concentration and purity, successful NGS amplification, and influences microbial communities seen in NGS output dependent on the species of fecal sample and the DNA extraction method used. These data highlight the importance of careful consideration of DNA extraction method used when designing and interpreting data from cross species studies.


    Institute of Scientific and Technical Information of China (English)

    Wahizatul Afzan A; Che Salmah M R


    Adult dragonfly communities were dominated by Libellulidae as 29 species were successfully collected from this family in marginal areas of Saleh, Setul and Serdang rivers. Zygopterans Coenagrionidae, Platycnemididae, Calopterygidae were common while Gomphidae and Chlorocyphidae were rather rare. Libellulids Neurothemis fluctuans, Trithemis aurora, Crocothemis servilia, T. festiva and Orthetrum chrysis were widely distributed in shaded, muddy areas. Among the zygopterans, Pseudagrion pruinosumwas the most dominant species. Agriocnemis femina, Ictinogomphus rapax, Cratilla lineata, Lathrecista asiatica, Neurothemis tullia, Tholymis tillarga and Copera ciliata were strictly found at Saleh River implicating their preference for smaller, slow moving and polluted river with floating microphytes and few other surrounding plant species. Neurobasis chinensis and Vestalis gracilis were only found in open, undisturbed, fast flowing waters of Setul and Serdang rivers. Generally the adults perched on marginal vegetation as well as those on the river bank areas.

  3. APOBEC3G polymorphism as a selective barrier to cross-species transmission and emergence of pathogenic SIV and AIDS in a primate host.

    Directory of Open Access Journals (Sweden)

    Annabel Krupp

    Full Text Available Cellular restriction factors, which render cells intrinsically resistant to viruses, potentially impose genetic barriers to cross-species transmission and emergence of viral pathogens in nature. One such factor is APOBEC3G. To overcome APOBEC3G-mediated restriction, many lentiviruses encode Vif, a protein that targets APOBEC3G for degradation. As with many restriction factor genes, primate APOBEC3G displays strong signatures of positive selection. This is interpreted as evidence that the primate APOBEC3G locus reflects a long-term evolutionary "arms-race" between retroviruses and their primate hosts. Here, we provide direct evidence that APOBEC3G has functioned as a barrier to cross-species transmission, selecting for viral resistance during emergence of the AIDS-causing pathogen SIVmac in captive colonies of Asian macaques in the 1970s. Specifically, we found that rhesus macaques have multiple, functionally distinct APOBEC3G alleles, and that emergence of SIVmac and simian AIDS required adaptation of the virus to evade APOBEC3G-mediated restriction. Our evidence includes the first comparative analysis of APOBEC3G polymorphism and function in both a reservoir and recipient host species (sooty mangabeys and rhesus macaques, respectively, and identification of adaptations unique to Vif proteins of the SIVmac lineage that specifically antagonize rhesus APOBEC3G alleles. By demonstrating that interspecies variation in a known restriction factor selected for viral counter-adaptations in the context of a documented case of cross-species transmission, our results lend strong support to the evolutionary "arms-race" hypothesis. Importantly, our study confirms that APOBEC3G divergence can be a critical determinant of interspecies transmission and emergence of primate lentiviruses, including viruses with the potential to infect and spread in human populations.

  4. Evidence of a species complex within the food-borne trematode Opisthorchis viverrini and possible co-evolution with their first intermediate hosts. (United States)

    Saijuntha, Weerachai; Sithithaworn, Paiboon; Wongkham, Sopit; Laha, Thewarach; Pipitgool, Vichit; Tesana, Smarn; Chilton, Neil B; Petney, Trevor N; Andrews, Ross H


    The food-borne trematodes, Opisthorchis viverrini, O. felineus and Clonorchis sinensis, have long been recognized as the cause of major human health problems, with an estimated 40 million infected persons. Of the three species of liver fluke, only O. viverrini is classified as a type 1 carcinogen because of its role as an initiator of chronic inflammation and the subsequent development of cholangiocarcinoma. At present, there are no techniques for the early diagnosis of cholangiocarcinoma and it is fatal for most patients. There is considerable variation in parasite prevalence and disease presentation in different geographical areas, the latter of which may be associated with genetic differences among parasites. In the present study, multilocus enzyme electrophoresis was used to provide a comprehensive genetic characterization of O. viverrini from different geographical localities in Thailand and the Peoples' Democratic Republic of Laos. Parasites from different localities were compared genetically at 32 enzyme loci. The results of the genetic analyses are sufficient to reject the null hypothesis that O. viverrini represents a single species. Therefore, O. viverrini consists of at least two genetically distinct, yet morphologically similar (i.e. cryptic) species. Moreover, there was also separation of the different populations of snails (i.e. the first intermediate hosts) into two distinct genetic groups that corresponded with the delineation of O. viverrini into two species. This suggests that there may be a history of co-evolution in this host-parasite lineage. Additionally, five distinct genetic groups of parasites were detected, each of which occurred within a different and independent river wetland system. Our findings have major implications for the implementation of effective control and surveillance programs targeted to these medically important food-borne parasites.

  5. A new species of Heteronybelinia (Cestoda: Trypanorhyncha) from Sympterygia bonapartii (Rajidae), Nemadactylus bergi (Cheilodactylidae) and Raneya brasiliensis (Ophidiidae) in the south-western Atlantic, with comments on host specificity of the genus. (United States)

    Menoret, A; Ivanov, V A


    Adults and plerocercoids of a new species of Heteronybelinia (Trypanorhyncha, Tentaculariidae) were recovered from the skate Sympterygia bonapartii (Rajiformes: Rajidae) and two species of teleosts, Raneya brasiliensis (Ophidiiformes: Ophidiidae) and Nemadactylus bergi (Perciformes: Cheilodactylidae), respectively. Heteronybelinia mattisi n. sp. differs from its congeners in its possession of a tentacular armature consisting of hooks with slight differences in size and shape on opposite surfaces of the tentacle (uncinate with rounded bases on the bothrial surface and uncinate with elongate bases on the antibothrial surface), without a characteristic basal armature, hooks increasing in size toward the tip of the tentacles, and pars bothrialis slightly overlapping with bulbs. The description of Heteronybelinia is emended regarding the distribution of testes to include species without postovarian testes (H. palliata and H. mattisi), and without testes anterior to cirrus sac on the poral side (H. robusta and H. mattisi). Host data are summarized for all 15 valid species of Heteronybelinia. Host specificity of adults and plerocercoids of Heteronybelinia is variable among species, the adults being more host specific than the plerocercoids. With the exception of H. mattisi, the definitive hosts of all species of Heteronybelinia for which adults are known include carcharhiniform sharks. Heteronybelinia mattisi seems to have oioxenous specificity for its definitive batoid host, S. bonapartii, and to be more specific for the intermediate hosts than most of its congeners.

  6. Host species and strain combination determine growth reduction of spruce and birch seedlings colonized by root-associated dark septate endophytes. (United States)

    Reininger, Vanessa; Grünig, Christoph R; Sieber, Thomas N


    Interactions of Betula pendula and Picea abies with dark septate endophytes of the Phialocephala fortinii-Acephala applanata species complex (PAC) were studied. PAC are ubiquitous fungal root symbionts of many woody plant species but their ecological role is largely unknown. Sterile birch and spruce seedlings in monoculture and mixed culture were exposed to four PAC strains, added either singularly or paired in all possible combinations at 18°C and 23°C. Plant and fungal biomass was determined after 4 months. The most significant factors were strain and host combination. One of the strains significantly reduced biomass gain of spruce but not of birch. Plant biomass was negatively correlated with total endophytic fungal biomass in half of the strain - plant combinations. Endophytic PAC biomass was four times higher in spruce (≈ 40 mg g(-1) drw) than in birch (≈ 10 mg g(-1) drw). Competition between strains was strain-dependent with some strains significantly reducing colonization density of other strains, and, thus, attenuating adverse effects of 'pathogenic' strains on plant growth in some strain - plant combinations. Biomass gain of spruce but not of birch was significantly reduced at higher temperature. In conclusion, host, fungal genotype, colonization density and presence of a competing PAC strain were the main determining factors for plant growth.

  7. Discovery of intermediate hosts for two species of blood flukes Cardicola orientalis and Cardicola forsteri (Trematoda: Aporocotylidae) infecting Pacific bluefin tuna in Japan. (United States)

    Shirakashi, Sho; Tani, Kazuki; Ishimaru, Katsuya; Shin, Sang Phil; Honryo, Tomoki; Uchida, Hiro'omi; Ogawa, Kazuo


    Fish blood flukes (Aporocotylidae) are important pathogens of farmed finfish around the world. Among them, Cardicola spp. infecting farmed tuna are considered to be serious threats to tuna farming and have received tremendous attention. We conducted periodical samplings at a tuna farming site in Japan between January and May, 2015 to determine the life cycle of Cardicola spp. We collected over 4700 terebellid polychaetes from ropes, floats and frames of tuna culture cages and found nearly 400 infected worms. Sporocysts and cercariae found in Nicolea gracilibranchis were genetically identified as Cardicola orientalis by 28S and ITS2 ribosomal DNA sequences. This was the first discovery of the intermediate host for this parasite species. Infection prevalence and the abundance of N. gracilibranchis significantly varied between sampling points and the highest number of infected terebellids were collected from ropes. We also demonstrated morphologically and molecularly that asexual stages found in a single Amphitrite sp. (Terebellidae) and adult worms isolated from farmed juvenile tuna were Cardicola forsteri. This is the first report of C. forsteri in Pacific bluefin tuna (PBT) Thunnus orientalis in Japan. Our results demonstrated that all three species of Cardicola orientalis, C. forsteri and Cardicola opisthorchis exist in Japanese farmed PBTs and that they all use terebellid polychaetes as the intermediate hosts. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  8. Effects of tea saponin on growth and development, nutritional indicators, and hormone titers in diamondback moths feeding on different host plant species. (United States)

    Cai, Hongjiao; Bai, Yan; Wei, Hui; Lin, Shuo; Chen, Yixin; Tian, Houjun; Gu, Xiaojun; Murugan, Kadarkarai


    The diamondback moth (DBM) is an important worldwide pest. This insect has been studied for several decades; however, its control remains problematic. Numerous chemical insecticides have become ineffective and chemical residues constitute an important problem. In the present study, we determined the mortality of 3rd instar DBM larvae feeding on three different host plant species and exposed to various concentrations of tea saponin (TS). In addition, we evaluated growth and development parameters, nutritional indicators, and juvenile hormone (JH) and molting hormone (MH) titers in 2nd instar larvae exposed to LC20 and LC50 doses of TS. We found that treatment of DBM larvae with LC20 and LC50 doses of TS led to lower growth rates, decreased feed consumption, reduced frass production, lower pupal weights, reduced percentage pupation, slower adult emergence percentages, and diminished fecundity, but prolonged durations of the larval and pupal periods. The efficiency of conversion of ingested and digested food increased, but the approximate digestibility did not differ significantly between treatments and controls. JH and MH titers were higher after TS treatment; these increases varied according to the host species and TS concentration. Our results indicate that TS represents a potential new alternative insecticide based on its natural origin, low cost, and minimum environmental impact.

  9. Suitability of five species of stored-product insects as hosts for development and reproduction of the parasitoid Anisopteromalus calandrae (Hymenoptera: Pteromalidae). (United States)

    Ghimire, Mukti N; Phillips, Thomas W


    We investigated the ability of two populations of Anisopteromalus calandrae (Hymenoptera: Pteromalidae), to parasitize and develop on late instars of five different stored-product insects that typically complete their development inside seeds of grain or legume species or other dry commodity. The host species were the cigarette beetle, Lasioderma serricorne (F.); cowpea weevil, Callosobruchus maculatus (F.); rice weevil, Sitophilus oryzae (L.); lesser grain borer, Rhyzopertha dominica (F.); and Angoumois grain moth, Sitotroga cerealella (Olivier). Experiments were conducted in the laboratory in a no-choice design by using petri dishes (15 by 100 mm) as experimental arenas with 20 host larvae. A. calandrae females from populations originating in Georgia (GA) and Oklahoma (OK) were introduced singly into experimental arenas and allowed to sting and oviposit for 24 h. Parasitism by the OK population was greater than that for the GA population across all hosts. However, no or very low parasitism was found on Angoumois grain moth for either population in this experiment. The highest number of parasitoid progeny was recorded on cowpea weevil (15.9) followed by rice weevil (11.5) and cigarette beetle (10.8) for the OK population. A similar trend was observed in the GA population. The highest proportion of female progeny was produced on cowpea weevil (73.0%) by the OK population. Conversely, a higher proportion of female progeny was produced on rice weevil (64.6%) by the GA population than produced by the OK population. Parasitoid adults were significantly larger and heavier when they developed on cowpea weevil irrespective of parasitoid population. The possible application of these results for biological control of stored-product insects is discussed.

  10. Genetic differences between blight-causing Erwinia species with differing host specificities, identified by suppression subtractive hybridization. (United States)

    Triplett, Lindsay R; Zhao, Youfu; Sundin, George W


    PCR-based subtractive hybridization was used to isolate sequences from Erwinia amylovora strain Ea110, which is pathogenic on apples and pears, that were not present in three closely related strains with differing host specificities: E. amylovora MR1, which is pathogenic only on Rubus spp.; Erwinia pyrifoliae Ep1/96, the causal agent of shoot blight of Asian pears; and Erwinia sp. strain Ejp556, the causal agent of bacterial shoot blight of pear in Japan. In total, six subtractive libraries were constructed and analyzed. Recovered sequences included type III secretion components, hypothetical membrane proteins, and ATP-binding proteins. In addition, we identified an Ea110-specific sequence with homology to a type III secretion apparatus component of the insect endosymbiont Sodalis glossinidius, as well as an Ep1/96-specific sequence with homology to the Yersinia pestis effector protein tyrosine phosphatase YopH.

  11. Molecular species identification, host preference and detection of myxoma virus in the Anopheles maculipennis complex (Diptera: Culicidae) in southern England, UK. (United States)

    Brugman, Victor A; Hernández-Triana, Luis M; Prosser, Sean W J; Weland, Chris; Westcott, David G; Fooks, Anthony R; Johnson, Nicholas


    Determining the host feeding patterns of mosquitoes by identifying the origin of their blood-meals is an important part of understanding the role of vector species in current and future disease transmission cycles. Collecting large numbers of blood-fed mosquitoes from the field is difficult, therefore it is important to maximise the information obtained from each specimen. This study aimed to use mosquito genome sequence to identify the species within Anopheles maculipennis sensu lato (An. maculipennis s.l.), identify the vertebrate hosts of field-caught blood-fed An. maculipennis s.l. , and to test for the presence of myxoma virus (Poxviridae, genus Leporipoxvirus) in specimens found to have fed on the European rabbit (Oryctolagus cuniculus). Blood-fed An. maculipennis s.l. were collected from resting sites at Elmley Nature Reserve, Kent, between June and September 2013. Hosts that An. maculipennis s.l. had fed on were determined by a PCR-sequencing approach based on the partial amplification of the mitochondrial cytochrome C oxidase subunit I gene. Mosquitoes were then identified to species by sequencing a region of the internal transcribed spacer-2. DNA extracts from all mosquitoes identified as having fed on rabbits were subsequently screened using PCR for the presence of myxoma virus. A total of 94 blood-fed Anopheles maculipennis s.l. were collected, of which 43 (46%) provided positive blood-meal identification results. Thirty-six of these specimens were identified as Anopheles atroparvus, which had fed on rabbit (n = 33, 92%) and cattle (n = 3, 8%). Seven mosquitoes were identified as Anopheles messeae, which had fed on cattle (n = 6, 86%) and dog (n = 1, 14%). Of the 33 An. atroparvus that contained rabbit blood, nine (27%) were positive for myxoma virus. Results demonstrate that a single DNA extract from a blood-fed mosquito can be successfully used for molecular identification of members of the An. maculipennis complex, blood

  12. A 10-year wildlife survey of 15 species of Canadian carnivores identifies new hosts or geographic locations for Trichinella genotypes T2, T4, T5, and T6. (United States)

    Gajadhar, Alvin A; Forbes, Lorry B


    A survey of wild carnivores in Canada was conducted over a 10-year period to determine the prevalence and genotypes of Trichinella. Muscle samples collected from 1409 animals representing 15 hosts species were enzymatically digested to recover Trichinella larvae. Larvae were recovered from a total of 287 (20.4%) animals and PCR identified four genotypes of Trichinella. Trichinella nativa was found in 5 host species and was the most commonly found genotype. Trichinella T6 was present in 7 species of carnivores, and coyote and badger are new host records for this genotype. The recovery of T. pseudospiralis and T. murrelli from cougars is the first documentation of these species in Canada and in cougars. The cougar was also the only host species in which all four genotypes of Trichinella were identified. Black bears and walruses had the highest tissue levels of larvae in this study and are also the species most frequently associated with human trichinellosis in Canada. This work identifies additional host species and expanded geographic ranges for 4 genotypes of Trichinella in North America. Failure to demonstrate T. spiralis in wildlife and continued negative results from ongoing surveillance activities in swine provide additional evidence that T. spiralis is not present in Canada.

  13. The genome of African yam (Dioscorea cayenensis-rotundata complex) hosts endogenous sequences from four distinct Badnavirus species. (United States)

    Umber, Marie; Filloux, Denis; Muller, Emmanuelle; Laboureau, Nathalie; Galzi, Serge; Roumagnac, Philippe; Iskra-Caruana, Marie-Line; Pavis, Claudie; Teycheney, Pierre-Yves; Seal, Susan E


    Several endogenous viral elements (EVEs) have been identified in plant genomes, including endogenous pararetroviruses (EPRVs). Here, we report the first characterization of EPRV sequences in the genome of African yam of the Dioscorea cayenensis-rotundata complex. We propose that these sequences should be termed 'endogenous Dioscorea bacilliform viruses' (eDBVs). Molecular characterization of eDBVs shows that they constitute sequences originating from various parts of badnavirus genomes, resulting in a mosaic structure that is typical of most EPRVs characterized to date. Using complementary molecular approaches, we show that eDBVs belong to at least four distinct Badnavirus species, indicating multiple, independent, endogenization events. Phylogenetic analyses of eDBVs support and enrich the current taxonomy of yam badnaviruses and lead to the characterization of a new Badnavirus species in yam. The impact of eDBVs on diagnosis, yam germplasm conservation and movement, and breeding is discussed. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  14. A new species of Smicromorpha (Hymenoptera, Chalcididae from Vietnam, with notes on the host association of the genus

    Directory of Open Access Journals (Sweden)

    Chris Darling


    Full Text Available Smicromorpha masneri Darling, sp. n. is described from Bach Ma National Park, Thua Thien-Hue Province, Vietnam. This is the first confirmed record for the genus on mainland southeast Asia. It is generally accepted that species of Smicromorpha are parasitoids of green tree or weaver ants, Oecophylla smaragdina (Fabricius but this is first rearing record of these parasitoids from the nests of weaver ants.

  15. Sea lamprey mark type, marking rate, and parasite-host relationships for lake trout and other species in Lake Ontario (United States)

    Lantry, Brian F.; Adams, Jean V.; Christie, Gavin; Schaner, Teodore; Bowlby, James; Keir, Michael; Lantry, Jana; Sullivan, Paul; Bishop, Daniel; Treska, Ted; Morrison, Bruce


    We examined how attack frequency by sea lampreys on fishes in Lake Ontario varied in response to sea lamprey abundance and preferred host abundance (lake trout > 433 mm). For this analysis we used two gill net assessment surveys, one angler creel survey, three salmonid spawning run datasets, one adult sea lamprey assessment, and a bottom trawl assessment of dead lake trout. The frequency of fresh sea lamprey marks observed on lake trout from assessment surveys was strongly related to the frequency of sea lamprey attacks observed on salmon and trout from the creel survey and spawning migrations. Attack frequencies on all salmonids examined were related to the ratio between the abundances of adult sea lampreys and lake trout. Reanalysis of the susceptibility to sea lamprey attack for lake trout strains stocked into Lake Ontario reaffirmed that Lake Superior strain lake trout were among the most and Seneca Lake strain among the least susceptible and that Lewis Lake strain lake trout were even more susceptible than the Superior strain. Seasonal attack frequencies indicated that as the number of observed sea lamprey attacks decreased during June–September, the ratio of healing to fresh marks also decreased. Simulation of the ratios of healing to fresh marks indicated that increased lethality of attacks by growing sea lampreys contributed to the decline in the ratios and supported laboratory studies about wound healing duration.

  16. One Shroom to Rule Them All: Identifying the mechanisms employed in ectomycorrhizal mutualisms for the generalist fungus Thelephora terrestris and seven genetically diverse host tree species (United States)

    Francis, N.; Laura, B.; Peay, K.


    This summer, through the Stanford EARTH Young Investigators Internship, I worked in the Peay fungal ecology lab to set up an experiment to identify what fungal mechanisms are at work in ectomycorrhizal mutualisms between seven phylogenetically distinct tree species and the generalist fungus Thelephora terrestris. Ectomycorrhizal fungi occupy an important niche in terrestrial ecology through their symbiotic mutualisms with plant hosts that allow for the exchange of carbon and nitrogen. However, very little is known about what determines partner choice for ectomycorrhizal fungal mutualists. Among pathogenic fungi, specialization on particular hosts is common, likely because the pathogen must work in specialized ways with the host's immune system. Ectomycorrhizal mutualists, however, tend to be generalists, even though their associations with plants are physically intimate and chemically complex. In order to understand how ectomycorrhizal fungi maintain a broad host range, I grew and planted seedlings and cuttings of Pinus muricata (bishop pine), Pseudotsuga menziesii (Douglas fir), Salix lasiolepis (arroyo willow), Populus trichocarpa (black cottonwood), Quercus agrifolia (coastal live oak), Eucalyptus globulus (blue gum), and Arbutus menziesii (Pacific madrone). Within each pot, the seven seedlings was planted around a previously planted donor bishop pine in potting mixture inoculated with Thelephora terrestris so that the fungus could spread from the donor pine to the others. I also helped analyze the extent of Thelephora terrestris growth on the plant roots from a preliminary round of the experiment in order to refine the data collection protocol for the coming experiment. Several months from now, my research mentor will label the carbon and nitrogen moving between the fungus and the plant to find out how well the symbiosis is working for each partner, and will sequence the RNA from the fungus to see if it uses different genes to communicate and associate with

  17. Combining a Climatic Niche Model of an Invasive Fungus with Its Host Species Distributions to Identify Risks to Natural Assets: Puccinia psidii Sensu Lato in Australia (United States)

    Kriticos, Darren J.; Morin, Louise; Leriche, Agathe; Anderson, Robert C.; Caley, Peter


    Puccinia psidii sensu lato (s.l.) is an invasive rust fungus threatening a wide range of plant species in the family Myrtaceae. Originating from Central and South America, it has invaded mainland USA and Hawai'i, parts of Asia and Australia. We used CLIMEX to develop a semi-mechanistic global climatic niche model based on new data on the distribution and biology of P. psidii s.l. The model was validated using independent distribution data from recently invaded areas in Australia, China and Japan. We combined this model with distribution data of its potential Myrtaceae host plant species present in Australia to identify areas and ecosystems most at risk. Myrtaceaeous species richness, threatened Myrtaceae and eucalypt plantations within the climatically suitable envelope for P. psidii s.l in Australia were mapped. Globally the model identifies climatically suitable areas for P. psidii s.l. throughout the wet tropics and sub-tropics where moist conditions with moderate temperatures prevail, and also into some cool regions with a mild Mediterranean climate. In Australia, the map of species richness of Myrtaceae within the P. psidii s.l. climatic envelope shows areas where epidemics are hypothetically more likely to be frequent and severe. These hotspots for epidemics are along the eastern coast of New South Wales, including the Sydney Basin, in the Brisbane and Cairns areas in Queensland, and in the coastal region from the south of Bunbury to Esperance in Western Australia. This new climatic niche model for P. psidii s.l. indicates a higher degree of cold tolerance; and hence a potential range that extends into higher altitudes and latitudes than has been indicated previously. The methods demonstrated here provide some insight into the impacts an invasive species might have within its climatically suited range, and can help inform biosecurity policies regarding the management of its spread and protection of valued threatened assets. PMID:23704988

  18. Combining a climatic niche model of an invasive fungus with its host species distributions to identify risks to natural assets: Puccinia psidii Sensu Lato in Australia.

    Directory of Open Access Journals (Sweden)

    Darren J Kriticos

    Full Text Available Puccinia psidii sensu lato (s.l. is an invasive rust fungus threatening a wide range of plant species in the family Myrtaceae. Originating from Central and South America, it has invaded mainland USA and Hawai'i, parts of Asia and Australia. We used CLIMEX to develop a semi-mechanistic global climatic niche model based on new data on the distribution and biology of P. psidii s.l. The model was validated using independent distribution data from recently invaded areas in Australia, China and Japan. We combined this model with distribution data of its potential Myrtaceae host plant species present in Australia to identify areas and ecosystems most at risk. Myrtaceaeous species richness, threatened Myrtaceae and eucalypt plantations within the climatically suitable envelope for P. psidii s.l in Australia were mapped. Globally the model identifies climatically suitable areas for P. psidii s.l. throughout the wet tropics and sub-tropics where moist conditions with moderate temperatures prevail, and also into some cool regions with a mild Mediterranean climate. In Australia, the map of species richness of Myrtaceae within the P. psidii s.l. climatic envelope shows areas where epidemics are hypothetically more likely to be frequent and severe. These hotspots for epidemics are along the eastern coast of New South Wales, including the Sydney Basin, in the Brisbane and Cairns areas in Queensland, and in the coastal region from the south of Bunbury to Esperance in Western Australia. This new climatic niche model for P. psidii s.l. indicates a higher degree of cold tolerance; and hence a potential range that extends into higher altitudes and latitudes than has been indicated previously. The methods demonstrated here provide some insight into the impacts an invasive species might have within its climatically suited range, and can help inform biosecurity policies regarding the management of its spread and protection of valued threatened assets.

  19. Identification of fruit volatiles from green hawthorn (Crataegus viridis) and blueberry hawthorn (Crataegus brachyacantha) host plants attractive to different phenotypes of Rhagoletis pomonella flies in the southern United States. (United States)

    Cha, Dong H; Powell, Thomas H Q; Feder, Jeffrey L; Linn, Charles E


    The apple maggot fly, Rhagoletis pomonella, infests several hawthorn species in the southern USA. In a companion paper, we showed that R. pomonella flies infesting two different mayhaw species (Crataegus opaca and C. aestivalis) can discriminate between volatile blends developed for each host fruit, and that these blends are different from previously constructed blends for northern fly populations that infest domestic apple (Malus domestica), downy hawthorn (Crataegus mollis), and flowering dogwood (Cornus florida). Here, we show by using coupled gas chromatography and electroantennographic detection (GC-EAD), gas chromatography with mass spectrometry (GC-MS), and flight tunnel bioassays, that two additional southern hawthorn fly populations infesting C. viridis (green hawthorn) and C. brachyacantha (blueberry hawthorn) also can discriminate between volatile blends for each host fruit type. A 9-component blend was developed for C. viridis (3-methylbutan-1-ol [5%], butyl butanoate [19.5%], propyl hexanoate [1.5%], butyl hexanoate [24%], hexyl butanoate [24%], pentyl hexanoate [2.5%], 1-octen-3-ol [0.5%], pentyl butanoate [2.5%], and (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) [20.5%]) and an 8-component blend for C. brachyacantha (3-methylbutan-1-ol [0.6%], butyl acetate [50%], pentyl acetate [3.5%], butyl butanoate [9%], butyl hexanoate [16.8%], hexyl butanoate [16.8%], 1-octen-3-ol [0.3%], and pentyl butanoate [3%]). Crataegus viridis and C. brachyacantha-origin flies showed significantly higher levels of upwind oriented flight to their natal blend in flight tunnel assays compared to the alternate, non-natal blend and previously developed northern host plant blends. The presence of DMNT in C. viridis and butyl acetate in C. brachyacantha appeared to be largely responsible for driving the differential response. This sharp behavioral distinction underscores the diversity of odor response phenotypes in the southern USA, points to possible host race formation in these

  20. A small-molecule norspermidine and norspermidine-hosting polyelectrolyte coatings inhibit biofilm formation by multi-species wastewater culture. (United States)

    Si, Xiurong; Quan, Xiangchun; Wu, Yachuan


    Norspermidine is a potent and non-bactericidal small-molecule inhibitor of biofilm growth. In this study, impacts of norspermidine on biofilm control and existing biofilm dispersal by a mixed culture from wastewater treatment systems were investigated. A surface-mediated releasing approach for prevention of bacterial biofilm formation was established via encapsulating norspermidine into polyelectrolyte multilayer coatings. Results showed that the presence of norspermidine (500-1000 μM) in medium remarkably prevented biofilm formation. Norspermidine was also effective in disassembling pre-formed biofilms. Norspermidine-containing multilayer coatings were successfully fabricated on glass slides via layer-by-layer deposition in polyethylenimine (PEI) and poly(acrylic acid) (PAA) solution. This coating exhibited a high anti-biofilm property against a mixed culture and three pure strains (Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli). The loading amount and space distribution of norspermidine in the multilayer coating were key factors influencing its anti-biofilm efficacy. The polymer coating with norspermidine loaded in each bilayer (each-layer-type) exhibited better anti-biofilm efficacy than the bottom-type and the top-type coating, which showed a stable biofilm inhibition rate of about 60 % even after 5-day leaching in aqueous solution. Norspermidine could retard bacterial adhesion and destruct biofilm matrix by reducing exopolysaccharides and extracellular DNA (eDNA) associated with bacteria instead of growth inhibition. Norspermidine and the norspermidine-hosting coatings in this study offer a great potential for the control of biofilms in the settings of water purification and wastewater treatment systems, which shows the advantage of broad spectrum and less risk of evolved bacterial resistance compared to conventional microbicidal agents (e.g., antibiotics).

  1. Review of the largest species group of the New World seed beetle genus Sennius Bridwell (Coleoptera: Chrysomelidae), with host plant associations. (United States)

    Viana, Jéssica Herzog; Ribeiro-Costa, Cibele Stramare


    Sennius Bridwell is a New World genus of Bruchinae. Most species are placed in eight groups. In this study the species of the S. abbreviatus group are reviewed based on characters of the external morphology and the male genitalia. The group includes 14 species, two of which are new: Sennius abbreviatus (Say, 1824), S. bondari (Pic, 1929), S. durangensis Johnson & Kingsolver, 1973, S. lawrencei Johnson, 1977, S. lebasi (Fåhraeus, 1839), S. leucostauros Johnson & Kingsolver, 1973, S. lojaensis (Pic, 1933), S. medialis (Sharp, 1885), S. nappi Ribeiro-Costa & Reynaud, 1998, S. rufomaculatus (Motschulsky, 1874), S. transversesignatus (Fåhraeus, 1839), S. trinotaticollis (Pic, 1930), S. vivi sp. nov. and S. flinte sp. nov. The S. abbreviatus group differs from other groups by the pattern of sclerites and the shape of the internal sac of the male genitalia, and has three subgroups, defined here. The lectotype of S. lebasi is designated. New host plant records are presented for S. lojaensis and S. transversesignatus, and new distribution records for S. lawrencei, S. lojaensis and S. trinotaticollis. 

  2. Osmia species (Hymenoptera, Megachilidae from the southeastern United States with modified facial hairs: taxonomy, host plants, and conservation status

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    Molly Rightmyer


    Full Text Available We describe females and males of Osmia (Melanosmia calaminthae sp. n., an apparent floral specialist on Calamintha ashei (Lamiaceae, and provide observations on the behavior of female bees on flowers of this plant. We also provide diagnostic information for Osmia (Diceratosmia conjunctoides Robertson, stat. n., and synonymize O. (Diceratosmia subfasciata miamiensis Mitchell with O. conjunctoides syn. n. Females of both O. calaminthae and O. conjunctoides are unique among North American Osmia forshort, erect, simple facial hairs, which are apparent adaptations for collecting pollen from nototribic flowers. Osmia calaminthae is currently only known from sandy scrub at four nearby sites in the southern Lake Wales Ridge in Highlands County, Florida, USA, while O. conjunctoides is known from limited but widespread sites in the southeastern USA. We discuss the conservation status of both species based on known or speculated floral associates and distributions.

  3. Host factors do not influence the colonization or infection by fluconazole resistant Candida species in hospitalized patients

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    Ho Yu-Huai


    Full Text Available Abstract Nosocomial yeast infections have significantly increased during the past two decades in industrialized countries, including Taiwan. This has been associated with the emergence of resistance to fluconazole and other antifungal drugs. The medical records of 88 patients, colonized or infected with Candida species, from nine of the 22 hospitals that provided clinical isolates to the Taiwan Surveillance of Antimicrobial Resistance of Yeasts (TSARY program in 1999 were reviewed. A total of 35 patients contributed fluconazole resistant strains [minimum inhibitory concentrations (MICs ≧ 64 mg/l], while the remaining 53 patients contributed susceptible ones (MICs ≦ 8 mg/l. Fluconazole resistance was more frequent among isolates of Candida tropicalis (46.5% than either C. albicans (36.8% or C. glabrata (30.8%. There was no significant difference in demographic characteristics or underlying diseases among patients contributing strains different in drug susceptibility.

  4. Insights into the relationships of Palearctic and Nearctic lymnaeids (Mollusca : Gastropoda by rDNA ITS-2 sequencing and phylogeny of stagnicoline intermediate host species of Fasciola hepatica

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    Bargues M.D.


    Full Text Available Fascioliasis by Fasciola hepatica is the vector-borne disease presenting the widest latitudinal, longitudinal and altitudinal distribution known. F. hepatica shows a great adaptation power to new environmental conditions which is the consequence of its own capacities together with the adaptation and colonization abilities of its specific vector hosts, freshwater snails of the family Lymnaeidae. Several lymnaeid species only considered as secondary contributors to the liver fluke transmission have, however, played a very important role in the geographic expansion of this disease. Many of them belong to the so-called "stagnicoline" type group. Stagnicolines have, therefore, a very important applied interest in the Holarctic region, to which they are geographically restricted. The present knowledge on the genetics of stagnicolines and on their parasite-host interrelationships is, however, far from being sufficient. The present paper analyses the relationships between Palaearctic and Nearctic stagnicoline species on the base of the new light furnished by the results obtained in nuclear rDNA ITS-2 sequencing and corresponding phylogenetic studies of the lymnaeid taxa Lymnaea (Stagnicola occulta, L. (S. palustris palustris (topotype specimens and L.(S. p. turricula from Europe. Natural infections with F. hepatica have been reported in all of them. Surprisingly, ITS-2 length and G C content of L. occulta were similar and perfectly fitted within the respective ranges known in North American stagnicolines. Nucleotide differences and genetic distances were higher between L. occulta and the other European stagnicolines than between L. occulta and the North American ones. The ITS-2 sequence of L. p. turricula from Poland differed from the other genotypes known from turricula in Europe. The phylogenetic trees using the maximum-parsimony, distance and maximum-likelihood methods confirmed (i the inclusion of L. occulta in the branch of North American

  5. Comparative infectivity of Fasciola hepatica metacercariae from isolates of the main and secondary reservoir animal host species in the Bolivian Altiplano high human endemic region. (United States)

    Valero, M A; Mas-Coma, S


    Fascioliasis due to Fasciola hepatica (Linnaeus, 1758) is an endemic disease on the Northern Bolivian Altiplano, where human prevalences and intensities are the highest known, sheep and cattle are the main reservoir hosts, and pigs and donkeys the secondary ones. Investigations were carried out to study the viability of metacercariae experimentally obtained from eggs shed by naturally infected Altiplanic sheep, cattle, pigs and donkeys. A total of 157 Wistar rats were infected with doses of 5, 10, 20 and 150 metacercariae. Metacercariae aged for different number of weeks were used to analyse the influence of age on their viability. The number of worms successfully developed in each rat was established by dissection. Results obtained show that metacercarial infectivity is dependent upon storage time, being lower when metacercariae are older. The maximum longevity is 31 weeks using doses of 20 metacercariae per rat and 48 weeks with 150 metacercariae per rat, although in the latter case only a very low percentage of worms is recovered. Age-related infectivity of metacercariae from Altiplanic F. hepatica does not significantly differ from that of the liver fluke in lowlands of other countries. Concerning the influence of the isolate according to host species, results indicate that metacercarial viabilities of pig and donkey isolates are similar to the viabilities of metacercariae of sheep and cattle isolates. Thus, pig and donkey have a high transmission potential capacity concerning this aspect. This fact is of great importance for the control of human and animal fascioliasis in this highly endemic zone.

  6. A global phylogenetic analysis in order to determine the host species and geography dependent features present in the evolution of avian H9N2 influenza hemagglutinin

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    Andrew R. Dalby


    Full Text Available A complete phylogenetic analysis of all of the H9N2 hemagglutinin sequences that were collected between 1966 and 2012 was carried out in order to build a picture of the geographical and host specific evolution of the hemagglutinin protein. To improve the quality and applicability of the output data the sequences were divided into subsets based upon location and host species.The phylogenetic analysis of hemagglutinin reveals that the protein has distinct lineages between China and the Middle East, and that wild birds in both regions retain a distinct form of the H9 molecule, from the same lineage as the ancestral hemagglutinin. The results add further evidence to the hypothesis that the current predominant H9N2 hemagglutinin lineage might have originated in Southern China. The study also shows that there are sampling problems that affect the reliability of this and any similar analysis. This raises questions about the surveillance of H9N2 and the need for wider sampling of the virus in the environment.The results of this analysis are also consistent with a model where hemagglutinin has predominantly evolved by neutral drift punctuated by occasional selection events. These selective events have produced the current pattern of distinct lineages in the Middle East, Korea and China. This interpretation is in agreement with existing studies that have shown that there is widespread intra-country sequence evolution.

  7. Temporal Patterns in the Abundance and Species Composition of Spiders on Host Plants of the Invasive Moth Epiphyas postvittana (Lepidoptera: Tortricidae). (United States)

    Hogg, Brian N; Mills, Nicholas J; Daane, Kent M


    Generalist predators such as spiders may help mitigate the spread and impact of exotic herbivores. The lack of prey specificity and long generation times of spiders may allow them to persist when pests are scarce, and to limit the growth of pest populations before they reach damaging levels. We examined whether resident spiders are likely to play a role in maintaining populations of the invasive light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), below outbreak levels in California. We surveyed the spider community on two E. postvittana host plants, the ornamental Australian tea tree, Leptospermum laevigatum, and the weed French broom, Genista monspessulana, to characterize spider and larval E. postvittana abundance and spider species composition throughout the year. Spider densities and species composition showed slight seasonal changes. Spiders were present during periods of high and low E. postvittana abundance. Anyphaenid hunting spiders, Anyphaena aperta Banks in Australian tea tree and Anyphaena pacifica Banks in French broom, dominated spider species composition at four of five sampled sites, and underwent only slight seasonal variation in abundance. Adult A. aperta were rare at all times of the year, suggesting that high mortality among juvenile A. aperta limits the potential of this species as a predator of E. postvittana. Nevertheless, the continued presence of spiders throughout the year indicates that the resident spider community is likely to play a key role in reducing E. postvittana populations in California. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  8. Parasitic worms stimulate host NADPH oxidases to produce reactive oxygen species that limit plant cell death and promote infection. (United States)

    Siddique, Shahid; Matera, Christiane; Radakovic, Zoran S; Hasan, M Shamim; Gutbrod, Philipp; Rozanska, Elzbieta; Sobczak, Miroslaw; Torres, Miguel Angel; Grundler, Florian M W


    Plants and animals produce reactive oxygen species (ROS) in response to infection. In plants, ROS not only activate defense responses and promote cell death to limit the spread of pathogens but also restrict the amount of cell death in response to pathogen recognition. Plants also use hormones, such as salicylic acid, to mediate immune responses to infection. However, there are long-lasting biotrophic plant-pathogen interactions, such as the interaction between parasitic nematodes and plant roots during which defense responses are suppressed and root cells are reorganized to specific nurse cell systems. In plants, ROS are primarily generated by plasma membrane-localized NADPH (reduced form of nicotinamide adenine dinucleotide phosphate) oxidases, and loss of NADPH oxidase activity compromises immune responses and cell death. We found that infection of Arabidopsis thaliana by the parasitic nematode Heterodera schachtii activated the NADPH oxidases RbohD and RbohF to produce ROS, which was necessary to restrict infected plant cell death and promote nurse cell formation. RbohD- and RbohF-deficient plants exhibited larger regions of cell death in response to nematode infection, and nurse cell formation was greatly reduced. Genetic disruption of SID2, which is required for salicylic acid accumulation and immune activation in nematode-infected plants, led to the increased size of nematodes in RbohD- and RbohF-deficient plants, but did not decrease plant cell death. Thus, by stimulating NADPH oxidase-generated ROS, parasitic nematodes fine-tune the pattern of plant cell death during the destructive root invasion and may antagonize salicylic acid-induced defense responses during biotrophic life stages.

  9. Molecular and Morphological Characterization of Fasciola spp. Isolated from Different Host Species in a Newly Emerging Focus of Human Fascioliasis in Iran

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    Reza Shafiei


    Full Text Available The current study aimed to find out the morphometric and genotypic divergences of the flukes isolated from different hosts in a newly emerging focus of human fascioliasis in Iran. Adult Fasciola spp. were collected from 34 cattle, 13 sheep, and 11 goats from Kohgiluyeh and Boyer-Ahmad province, southwest of Iran. Genomic DNA was extracted from the flukes and PCR-RFLP was used to characterize the isolates. The ITS1, ITS2, and mitochondrial genes (mtDNA of NDI and COI from individual liver flukes were amplified and the amplicons were sequenced. Genetic variation within and between the species was evaluated by comparing the sequences. Moreover, morphometric characteristics of flukes were measured through a computer image analysis system. Based on RFLP profile, from the total of 58 isolates, 41 isolates (from cattle, sheep, and goat were identified as Fasciola hepatica, while 17 isolates from cattle were identified as Fasciola gigantica. Comparison of the ITS1 and ITS2 sequences showed six and seven single-base substitutions, resulting in segregation of the specimens into two different genotypes. The sequences of COI markers showed seven DNA polymorphic sites for F. hepatica and 35 DNA polymorphic sites for F. gigantica. Morphological diversity of the two species was observed in linear, ratios, and areas measurements. The findings have implications for studying the population genetics, epidemiology, and control of the disease.

  10. Molecular and Morphological Characterization of Fasciola spp. Isolated from Different Host Species in a Newly Emerging Focus of Human Fascioliasis in Iran. (United States)

    Shafiei, Reza; Sarkari, Bahador; Sadjjadi, Seyed Mahmuod; Mowlavi, Gholam Reza; Moshfe, Abdolali


    The current study aimed to find out the morphometric and genotypic divergences of the flukes isolated from different hosts in a newly emerging focus of human fascioliasis in Iran. Adult Fasciola spp. were collected from 34 cattle, 13 sheep, and 11 goats from Kohgiluyeh and Boyer-Ahmad province, southwest of Iran. Genomic DNA was extracted from the flukes and PCR-RFLP was used to characterize the isolates. The ITS1, ITS2, and mitochondrial genes (mtDNA) of NDI and COI from individual liver flukes were amplified and the amplicons were sequenced. Genetic variation within and between the species was evaluated by comparing the sequences. Moreover, morphometric characteristics of flukes were measured through a computer image analysis system. Based on RFLP profile, from the total of 58 isolates, 41 isolates (from cattle, sheep, and goat) were identified as Fasciola hepatica, while 17 isolates from cattle were identified as Fasciola gigantica. Comparison of the ITS1 and ITS2 sequences showed six and seven single-base substitutions, resulting in segregation of the specimens into two different genotypes. The sequences of COI markers showed seven DNA polymorphic sites for F. hepatica and 35 DNA polymorphic sites for F. gigantica. Morphological diversity of the two species was observed in linear, ratios, and areas measurements. The findings have implications for studying the population genetics, epidemiology, and control of the disease.

  11. Diversity Profile and Dynamics of Peptaibols Produced by Green Mould Trichoderma Species in Interactions with Their Hosts Agaricus bisporus and Pleurotus ostreatus. (United States)

    Marik, Tamás; Urbán, Péter; Tyagi, Chetna; Szekeres, András; Leitgeb, Balázs; Vágvölgyi, Máté; Manczinger, László; Druzhinina, Irina S; Vágvölgyi, Csaba; Kredics, László


    Certain Trichoderma species are causing serious losses in mushroom production worldwide. Trichoderma aggressivum and Trichoderma pleuroti are among the major causal agents of the green mould diseases affecting Agaricus bisporus and Pleurotus ostreatus, respectively. The genus Trichoderma is well-known for the production of bioactive secondary metabolites, including peptaibols, which are short, linear peptides containing unusual amino acid residues and being synthesised via non-ribosomal peptide synthetases (NRPSs). The aim of this study was to get more insight into the peptaibol production of T. aggressivum and T. pleuroti. HPLC/MS-based methods revealed the production of peptaibols closely related to hypomurocins B by T. aggressivum, while tripleurins representing a new group of 18-residue peptaibols were identified in T. pleuroti. Putative NRPS genes enabling the biosynthesis of the detected peptaibols could be found in the genomes of both Trichoderma species. In vitro experiments revealed that peptaibols are potential growth inhibitors of mushroom mycelia, and that the host mushrooms may have an influence on the peptaibol profiles of green mould agents. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  12. Effects of host species and life stage on the helminth communities of sympatric northern leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) in the Sheyenne National Grasslands, North Dakota. (United States)

    Gustafson, Kyle D; Newman, Robert A; Tkach, Vasyl V


    We studied helminth communities in sympatric populations of leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) and assessed the effects of host species and life stage on helminth community composition and helminth species richness. We examined 328 amphibians including 218 northern leopard frogs and 110 wood frogs collected between April and August of 2009 and 2010 in the Sheyenne National Grasslands of southeastern North Dakota. Echinostomatid metacercariae were the most common helminths found, with the highest prevalence in metamorphic wood frogs. Host species significantly influenced helminth community composition, and host life stage significantly influenced the component community composition of leopard frogs. In these sympatric populations, leopard frogs were common hosts for adult trematodes whereas wood frogs exhibited a higher prevalence of nematodes with direct life cycles. Metamorphic frogs were commonly infected with echinostomatid metacercariae and other larval trematodes whereas juvenile and adult frogs were most-frequently infected with directly transmitted nematodes and trophically transmitted trematodes. Accordingly, helminth species richness increased with the developmental life stage of the host.

  13. Host-parasite relationships of Rhabdochona kidderi Pearse, 1936 (Nematoda: Rhabdochonidae) in fishes of the Lacantún River in the Lacandon rain forest of Chiapas State, southern Mexico, with a key to Mexican species of Rhabdochona Railliet, 1916. (United States)

    Moravec, František; Salgado-Maldonado, Guillermo; González-Solís, David; Caspeta-Mandujano, Juan M


    For the first time, the nematode Rhabdochona kidderi kidderi Pearse, 1936 (Rhabdochonidae) was recorded from fishes of the Lacantún River (Usumacinta River basin) in the Lacandon rain forest, Chiapas State, southern Mexico. Amphilophus nourissati (Allgayer) and Theraps irregularis Günther (both Perciformes: Cichlidae) were found to be the only definitive hosts in the locality, whereas Eugerres mexicanus (Steindachner) (Perciformes: Gerreidae), Ariopsis sp., Cathorops aguadulce (Meek) and Potomarius nelsoni (Evermann & Goldsborough) (all Siluriformes: Ariidae), Ictalurus furcatus (Valenciennes) (Siluriformes: Ictaluridae) and Strongylura hubbsi Collette (Beloniformes: Belonidae) all harboured the nematode's fourth-stage larva and only served as paratenic hosts. All these fish species represent new host records for this parasite. The morphology of both adults and larvae was studied in detail by light and scanning electron microscopy, and some conspecific museum specimens from three other host species were also examined for comparison. Rhabdochona ictaluri Aguilar-Aguilar, Rosas-Valdez & Pérez-Ponce de León, 2010 is considered here to be a junior synonym of R. kidderi kidderi. A high degree of the variability of some morphological and biometrical features (deirid shape, left spicule length) and an unusually wide range of hosts suggest that R. kidderi may represent a species complex, but further studies are necessary in this respect. A key to Rhabdochona species and subspecies occurring in Mexico is provided.

  14. The Perfect Burrow, but for What? Identifying Local Habitat Conditions Promoting the Presence of the Host and Vector Species in the Kazakh Plague System (United States)

    Wilschut, Liesbeth; Addink, Elisabeth; Ageyev, Vladimir; Yeszhanov, Aidyn; Sapozhnikov, Valerij; Belayev, Alexander; Davydova, Tania; Eagle, Sally; Begon, Mike


    Introduction The wildlife plague system in the Pre-Balkhash desert of Kazakhstan has been a subject of study for many years. Much progress has been made in generating a method of predicting outbreaks of the disease (infection by the gram negative bacterium Yersinia pestis) but existing methods are not yet accurate enough to inform public health planning. The present study aimed to identify characteristics of individual mammalian host (Rhombomys opimus) burrows related to and potentially predictive of the presence of R.opimus and the dominant flea vectors (Xenopsylla spp.). Methods Over four seasons, burrow characteristics, their current occupancy status, and flea and tick burden of the occupants were recorded in the field. A second data set was generated of long term occupancy trends by recording the occupancy status of specific burrows over multiple occasions. Generalised linear mixed models were constructed to identify potential burrow properties predictive of either occupancy or flea burden. Results At the burrow level, it was identified that a burrow being occupied by Rhombomys, and remaining occupied, were both related to the characteristics of the sediment in which the burrow was constructed. The flea burden of Rhombomys in a burrow was found to be related to the tick burden. Further larger scale properties were also identified as being related to both Rhombomys and flea presence, including latitudinal position and the season. Conclusions Therefore, in advancing our current predictions of plague in Kazakhstan, we must consider the landscape at this local level to increase our accuracy in predicting the dynamics of gerbil and flea populations. Furthermore this demonstrates that in other zoonotic systems, it may be useful to consider the distribution and location of suitable habitat for both host and vector species at this fine scale to accurately predict future epizootics. PMID:26325073

  15. Especies de Megacerus (Coleoptera: Bruchidae y sus plantas hospederas en Yucatán Megacerus species (Coleoptera: Bruchidae and their host plants in Yucatán

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    Enrique Reyes


    . hederifolia and I. triloba ones by M. (M. cubiculus, and I. nil ones by M. (M. tricolor. Individuals of Megacerus (M. sp., hatched exclusively from J. penthanta seeds. At level of host plant gender, Ipomoea was overall attacked by M. (M. cubiculus and Merremia was by M. (M. porosus. Our results increase the number of host plants reported for Megacerus and suggest a close interaction between one lineage of Bruchidae and species of the Convolvulaceae family.

  16. Host Phylogeny Determines Viral Persistence and Replication in Novel Hosts (United States)

    Longdon, Ben; Hadfield, Jarrod D.; Webster, Claire L.


    Pathogens switching to new hosts can result in the emergence of new infectious diseases, and determining which species are likely to be sources of such host shifts is essential to understanding disease threats to both humans and wildlife. However, the factors that determine whether a pathogen can infect a novel host are poorly understood. We have examined the ability of three host-specific RNA-viruses (Drosophila sigma viruses from the family Rhabdoviridae) to persist and replicate in 51 different species of Drosophilidae. Using a novel analytical approach we found that the host phylogeny could explain most of the variation in viral replication and persistence between different host species. This effect is partly driven by viruses reaching a higher titre in those novel hosts most closely related to the original host. However, there is also a strong effect of host phylogeny that is independent of the distance from the original host, with viral titres being similar in groups of related hosts. Most of this effect could be explained by variation in general susceptibility to all three sigma viruses, as there is a strong phylogenetic correlation in the titres of the three viruses. These results suggest that the source of new emerging diseases may often be predictable from the host phylogeny, but that the effect may be more complex than simply causing most host shifts to occur between closely related hosts. PMID:21966271

  17. Infection of type I interferon receptor-deficient mice with various old world arenaviruses: a model for studying virulence and host species barriers.

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    Toni Rieger

    Full Text Available Lassa virus causes hemorrhagic Lassa fever in humans, while the related Old World arenaviruses Mopeia, Morogoro, and Mobala are supposedly apathogenic to humans and cause only inapparent infection in non-human primates. Here, we studied whether the virulence of Old World arenaviruses in humans and non-human primates is reflected in type I interferon receptor deficient (IFNAR(-/- mice by testing several strains of Lassa virus vs. the apathogenic viruses Mopeia, Morogoro, and Mobala. All Lassa virus strains tested-Josiah, AV, BA366, and Nig04-10-replicated to high titers in blood, lung, kidney, heart, spleen, brain, and liver and caused disease as evidenced by weight loss and elevation of aspartate and alanine aminotransferase (AST and ALT levels with a high AST/ALT ratio. Lassa fever-like pathology included acute hepatitis, interstitial pneumonia, and pronounced disturbance of splenic cytoarchitecture. Infiltrations of activated monocytes/macrophages expressing inducible nitric oxide synthase and T cells were found in liver and lung. In contrast, Mopeia, Morogoro, and Mobala virus replicated poorly in the animals and acute inflammatory alterations were not noted. Depletion of CD4(+ and CD8(+ T cells strongly enhanced susceptibility of IFNAR(-/- mice to the apathogenic viruses. In conclusion, the virulence of Old World arenaviruses in IFNAR(-/- mice correlates with their virulence in humans and non-human primates. In addition to the type I interferon system, T cells seem to regulate whether or not an arenavirus can productively infect non-host rodent species. The observation that Lassa virus overcomes the species barrier without artificial depletion of T cells suggests it is able to impair T cell functionality in a way that corresponds to depletion.

  18. Infection of type I interferon receptor-deficient mice with various old world arenaviruses: a model for studying virulence and host species barriers. (United States)

    Rieger, Toni; Merkler, Doron; Günther, Stephan


    Lassa virus causes hemorrhagic Lassa fever in humans, while the related Old World arenaviruses Mopeia, Morogoro, and Mobala are supposedly apathogenic to humans and cause only inapparent infection in non-human primates. Here, we studied whether the virulence of Old World arenaviruses in humans and non-human primates is reflected in type I interferon receptor deficient (IFNAR(-/-)) mice by testing several strains of Lassa virus vs. the apathogenic viruses Mopeia, Morogoro, and Mobala. All Lassa virus strains tested-Josiah, AV, BA366, and Nig04-10-replicated to high titers in blood, lung, kidney, heart, spleen, brain, and liver and caused disease as evidenced by weight loss and elevation of aspartate and alanine aminotransferase (AST and ALT) levels with a high AST/ALT ratio. Lassa fever-like pathology included acute hepatitis, interstitial pneumonia, and pronounced disturbance of splenic cytoarchitecture. Infiltrations of activated monocytes/macrophages expressing inducible nitric oxide synthase and T cells were found in liver and lung. In contrast, Mopeia, Morogoro, and Mobala virus replicated poorly in the animals and acute inflammatory alterations were not noted. Depletion of CD4(+) and CD8(+) T cells strongly enhanced susceptibility of IFNAR(-/-) mice to the apathogenic viruses. In conclusion, the virulence of Old World arenaviruses in IFNAR(-/-) mice correlates with their virulence in humans and non-human primates. In addition to the type I interferon system, T cells seem to regulate whether or not an arenavirus can productively infect non-host rodent species. The observation that Lassa virus overcomes the species barrier without artificial depletion of T cells suggests it is able to impair T cell functionality in a way that corresponds to depletion.

  19. Association and host selectivity in multi-host pathogens.

    Directory of Open Access Journals (Sweden)

    José M Malpica

    Full Text Available The distribution of multi-host pathogens over their host range conditions their population dynamics and structure. Also, host co-infection by different pathogens may have important consequences for the evolution of hosts and pathogens, and host-pathogen co-evolution. Hence it is of interest to know if the distribution of pathogens over their host range is random, or if there are associations between hosts and pathogens, or between pathogens sharing a host. To analyse these issues we propose indices for the observed patterns of host infection by pathogens, and for the observed patterns of co-infection, and tests to analyse if these patterns conform to randomness or reflect associations. Applying these tests to the prevalence of five plant viruses on 21 wild plant species evidenced host-virus associations: most hosts and viruses were selective for viruses and hosts, respectively. Interestingly, the more host-selective viruses were the more prevalent ones, suggesting that host specialisation is a successful strategy for multi-host pathogens. Analyses also showed that viruses tended to associate positively in co-infected hosts. The developed indices and tests provide the tools to analyse how strong and common are these associations among different groups of pathogens, which will help to understand and model the population biology of multi-host pathogens.

  20. Molecular Characterization of Staphylococcus aureus Isolated from Bovine Mastitis and Close Human Contacts in South African Dairy Herds: Genetic Diversity and Inter-Species Host Transmission (United States)

    Schmidt, Tracy; Kock, Marleen M.; Ehlers, Marthie M.


    Staphylococcus aureus is one of the most common etiological agents of contagious bovine mastitis worldwide. The purpose of this study was to genetically characterize a collection of S. aureus isolates (bovine = 146, human = 12) recovered from cases of bovine mastitis and nasal swabs of close human contacts in the dairy environment. Isolates were screened for a combination of clinically significant antimicrobial and virulence gene markers whilst the molecular epidemiology of these isolates and possible inter-species host transmission was investigated using a combination of genotyping techniques. None of the isolates under evaluation tested positive for methicillin or vancomycin resistance encoding genes. Twenty seven percent of the bovine S. aureus isolates tested positive for one or more of the pyrogenic toxin superantigen (PTSAg) genes with the sec and sell genes predominating. Comparatively, 83% of the human S. aureus isolates tested positive for one or more PTSAg genes with a greater variety of genes being detected. Genomic DNA macrorestriction followed by pulsed-field gel electrophoresis (PFGE) of the bovine isolates generated 58 electrophoretic patterns which grouped into 10 pulsotypes at an 80% similarity level. The majority of the bovine isolates, 93.2% (136/146), clustered into four major pulsotypes. Seven sequence types (ST) were identified among the representative bovine S. aureus isolates genotyped, including: ST8 (CC8), ST97 (CC97), ST351 (CC705), ST352 (CC97), ST508 (CC45), ST2992 (CC97) and a novel sequence type, ST3538 (CC97). Based on PFGE analysis, greater genetic diversity was observed among the human S. aureus isolates. Bovine and human isolates from three sampling sites clustered together and were genotypically indistinguishable. Two of the isolates, ST97 and ST352 belong to the common bovine lineage CC97, and their isolation from close human contacts suggests zoonotic transfer. In the context of this study, the third isolate, ST8 (CC8), is

  1. Jumping-ship can have its costs: implications of predation and host plant species for the maintenance of pea aphid (Acyrthosiphon pisum Harris) colour polymorphism. (United States)

    Balog, Adalbert


    The interplay between the host plant of an insect herbivore and an insect predator (here two-spot ladybird beetles; Adalia bipunctata (L).; Coleoptera: Coccinellidae), feeding upon such a herbivore was examined in the laboratory as factors possibly determining the differential abundance and success of green and red host races of pea aphid, Acyrthosiphon pisum Harris. The experiment comprised three treatments: two host plants (bean and clover), two treatment levels (control and predation) and three colour morph levels (green alone, red alone and green and red in mixture). Green morphs had higher fitness on the general host plant, bean Vicia faba, than on the derived host, clover (Trifolium pratense), in the absence of predation. Although green morph fitness was reduced by predation when infesting bean together with reds, there was no observable net fitness loss due to predation on clover in mixed colonies with red morphs. Red morphs exhibited fitness loss alone on both bean and clover, while clover plants seemingly prevented fitness loss in the presence of predation when red morphs were mixed with green ones. According to this scenario, when colour morphs existed as a mixed colony, the net fitness of either pea aphid morph was not influenced by predation on clover. Predators had significant effects only on red morphs on broad bean either when alone or were mixed together with green morphs. Thus, only red morphs experienced the benefits of switching from the general to the derived host red clover in the presence of predation. For green morphs, there was no apparent cost of switching host plants when they faced predation. Hence, the co-existence of green-red colour polymorphism of pea aphids on single host plants appears to be maintained by the morph gaining fitness on the derived host due to a host plant– and predation–reduction effect. These findings have important implications for understanding the ecology and evolution of host switching by different colour

  2. HostPhinder: A Phage Host Prediction Tool

    DEFF Research Database (Denmark)

    Villarroel, Julia; Kleinheinz, Kortine Annina; Jurtz, Vanessa Isabell


    The current dramatic increase of antibiotic resistant bacteria has revitalised the interest in bacteriophages as alternative antibacterial treatment. Meanwhile, the development of bioinformatics methods for analysing genomic data places high-throughput approaches for phage characterization within...... reach. Here, we present HostPhinder, a tool aimed at predicting the bacterial host of phages by examining the phage genome sequence. Using a reference database of 2196 phages with known hosts, HostPhinder predicts the host species of a query phage as the host of the most genomically similar reference...... phages. As a measure of genomic similarity the number of co-occurring k-mers (DNA sequences of length k) is used. Using an independent evaluation set, HostPhinder was able to correctly predict host genus and species for 81% and 74% of the phages respectively, giving predictions for more phages than BLAST...

  3. Evidence for potential of managing some african fruit fly species (Diptera: Tephritidae) using the mango fruit fly host-marking pheromone (United States)

    We investigated conspecific and heterospecific oviposition host discrimination among four economically important fruit fly pests of mango in Africa (Ceratitis capitata, Wiedemann; C. fasciventris, Bezzi; C. rosa, Karsch, and C. cosyra, Walker) with regard to host-marking behavior and fecal matter aq...

  4. Conserved host-pathogen PPIs. Globally conserved inter-species bacterial PPIs based conserved host-pathogen interactome derived novel target in C. pseudotuberculosis, C. diphtheriae, M. tuberculosis, C. ulcerans, Y. pestis, and E. coli targeted by Piper betel compounds

    DEFF Research Database (Denmark)

    Barh, Debmalya; Gupta, Krishnakant; Jain, Neha


    to generate a conserved host-pathogen interaction (HP-PPI) network considering human, goat, sheep, bovine, and horse as hosts. The HP-PPI network was validated, and acetate kinase (Ack) was identified as a novel broad spectrum target. Ceftiofur, penicillin, and two natural compounds derived from Piper betel...... were predicted to inhibit Ack activity. One of these Piper betel compounds found to inhibit E. coli O157:H7 growth similar to penicillin. The target specificity of these betel compounds, their effects on other studied pathogens, and other in silico results are currently being validated and the results...

  5. Host-derived pentapeptide affecting adhesion, proliferation, and local pH in biofilm communities composed of Streptococcus and Actinomyces species

    DEFF Research Database (Denmark)

    Drobni, M.; Li, T.; Krüger, C.


    genospecies 2 (5 of 10 strains) but not of S. gordonii (n=5). The inhibitable A. naeslundii strains alone displayed the same binding profile as S. gordonii to hybrid peptides terminating in RGRPQ or GQSPQ, derived from the middle or C-terminal segments of PRP-1. The present findings indicate the presence...... of a host-bacterium interaction in which a host peptide released by bacterial proteolysis affects key properties in biofilm formation....

  6. Plantas cultivadas e invasoras como habitat para predadores do gênero Orius(Wolff (Heteroptera: anthocoridae Crops and weeds as host plants Orius species (Heteroptera: anthocoridae

    Directory of Open Access Journals (Sweden)

    Luís Cláudio Paterno Silveira


    Full Text Available O objetivo deste trabalho foi registrar as espécies de Orius associadas a plantas cultivadas e invasoras presentes em uma localidade de Minas Gerais e três de São Paulo, nos anos de 1999 e 2000. As coletas foram realizadas através de batidas das plantas no interior de sacos plásticos para desalojar os insetos. Posteriormente, as espécies foram separadas em laboratório. O predador Orius insidiosus (Say foi coletado nas culturas de milho (Zea mays L., milheto (Pennisetum glaucum (L. R.Br., sorgo (Sorghum spp., feijão (Phaseolus vulgaris L., girassol (Helianthus annuus L., alfafa (Medicago sativa L., soja [Glycine max (L. Merr.], crisântemo (Chrysanthemum spp., tango (Solidago canadensis L. e cartamus (Carthamus tinctorius L. e nas plantas invasoras picão-preto (Bidens pilosa L., caruru (Amaranthus sp., losna-branca (Parthenium hysterophorus L. e apaga-fogo (Alternanthera ficoidea L.. Orius thyestes Herring foi encontrado nas plantas invasoras picão-preto, caruru e apaga-fogo. Orius perpunctatus (Reuter e Orius sp. foram coletados principalmente nas plantas invasoras picão-preto, caruru e apaga-fogo e no milho. Constatou-se que muitas dessas plantas são reservatórios naturais para esses predadores, em termos de habitat, abrigo, presas e pólen.The aim of this research was to record the Orius species present on some crops and weeds in areas located in the southeast region in Brazil, during 1999 and 2000. The insect collections were made through the tapping method to dislodge the insects from the plant into a plastic bag. The identifications of the specimens was done in the laboratory. Orius insidiosus (Say was collected on the following crops: corn (Zea mays L., pearl millet (Pennisetum glaucum (L. R.Br., sorghum (Sorghum spp., bean (Phaseolus vulgaris L., sunflower (Helianthus annuus L., alfalfa (Medicago sativa L., soybean (Glycine max (L. Merr., chrysanthemum (Chrysanthemum spp., tango (Solidago canadensis L. and carthamus

  7. Ability of a Generalist Seed Beetle to Colonize an Exotic Host: Effects of Host Plant Origin and Oviposition Host. (United States)

    Amarillo-Suárez, A; Repizo, A; Robles, J; Diaz, J; Bustamante, S


    The colonization of an exotic species by native herbivores is more likely to occur if that herbivore is a generalist. There is little information on the life-history mechanisms used by native generalist insects to colonize exotic hosts and how these mechanisms are affected by host properties. We examined the ability of the generalist seed beetle Stator limbatus Horn to colonize an exotic species. We compared its host preference, acceptability, performance, and egg size when ovipositing and developing on two native (Pithecellobium dulce (Roxb.) Benth and Senegalia riparia (Kunth)) and one exotic legume species (Leucaena leucocephala (Lam.)). We also analyzed the seed chemistry. We found that females recognize the exotic species as an unfavorable host for larval development and that they delayed oviposition and laid fewer and larger eggs on the exotic species than on the native species. Survivorship on the exotic host was 0%. Additionally, seeds of the native species contain five chemical compounds that are absent in the exotic species, and the exotic species contains three sterols, which are absent in the native legumes. Genetically based differences between beetles adapted to different hosts, plastic responses toward new hosts, and chemical differences among seeds are important in host colonization and recognition of the exotic host. In conclusion, the generalist nature of S. limbatus does not influence its ability to colonize L. leucocephala. Explanations for the colonization of exotic hosts by generalist native species and for the success of invasive species must be complemented with studies measuring local adaptation and plasticity.

  8. Visual mimicry of host nestlings by cuckoos (United States)

    Langmore, Naomi E.; Stevens, Martin; Maurer, Golo; Heinsohn, Robert; Hall, Michelle L.; Peters, Anne; Kilner, Rebecca M.


    Coevolution between antagonistic species has produced instances of exquisite mimicry. Among brood-parasitic cuckoos, host defences have driven the evolution of mimetic eggs, but the evolutionary arms race was believed to be constrained from progressing to the chick stage, with cuckoo nestlings generally looking unlike host young. However, recent studies on bronze-cuckoos have confounded theoretical expectations by demonstrating cuckoo nestling rejection by hosts. Coevolutionary theory predicts reciprocal selection for visual mimicry of host young by cuckoos, although this has not been demonstrated previously. Here we show that, in the eyes of hosts, nestlings of three bronze-cuckoo species are striking visual mimics of the young of their morphologically diverse hosts, providing the first evidence that coevolution can select for visual mimicry of hosts in cuckoo chicks. Bronze-cuckoos resemble their own hosts more closely than other host species, but the accuracy of mimicry varies according to the diversity of hosts they exploit. PMID:21227972

  9. The first record of Baccharis L. (Asteraceae) as a host-plant genus for Nepticulidae (Lepidoptera), with description of new Stigmella species from South America (United States)

    We record the first Nepticulidae species found to feed on Baccharis L. (Asteraceae). Despite the high species richness of Baccharis in the Western Hemisphere, no nepticulid has ever been recorded feeding on Baccharis. In this paper we describe four new Stigmella Schrank species feeding on Baccharis:...

  10. Tabela de vida de fertilidade de três espécies neotropicais de Trichogrammatidae em ovos de hospedeiros alternativos como critério de seleção hospedeira Fertility life table of three neotropical species of Trichogrammatidae on factitious hosts as a criterion for selection of hosts

    Directory of Open Access Journals (Sweden)

    Nivia da Silva Dias


    Full Text Available Tabela de vida de fertilidade de três espécies neotropicais de Trichogrammatidae em ovos de hospedeiros alternativos como critério de seleção hospedeira. O objetivo deste trabalho foi selecionar o hospedeiro alternativo que permita o melhor desenvolvimento das três espécies neotropicais de tricogramatídeos, Trichogramma atopovirilia Oatman & Platner, 1983; Trichogramma bruni Nagaraja, 1983 e Trichogrammatoidea annulata De Santis, 1972, utilizando-se como parâmetro comparativo as tabelas de vida de fertilidade nos respectivos hospedeiros. Foram estimados a duração média de uma geração (T, taxa líquida de reprodução (Ro, razão infinitesimal (r m e a razão finita de aumento (λ. A tabela de vida de fertilidade pode ser utilizada para selecionar o hospedeiro alternativo mais adequado para as espécies de tricogramatídeos. Corcyra cephalonica (Stainton, 1865 (Lepidoptera, Pyralidae foi o hospedeiro alternativo mais adequado para criação de T. annulata e de T. bruni, enquanto que para T. atopovirilia, Anagasta kuehniella (Zeller, 1879 (Lepidoptera, Pyralidae e/ou C. cephalonica foram os hospedeiros mais adequados. Sitotroga cerealella (Olivier, 1819 (Lepidoptera, Gelechiidae apresentou baixa capacidade de aumento populacional para as três espécies de parasitóides, sendo, portanto, uma espécie inadequada como hospedeiro alternativo para as mesmas.The objective of this work was to select the factitious host that permit the best development of three neotropical Trichogrammatidae species, Trichogramma atopovirilia Oatman & Platner, 1983; Trichogramma bruni Nagaraja, 1983, and Trichogrammatoidea annulata De Santis, 1972, using the fertility life table on their respective hosts as a comparative parameter. Mean generation time (T, net reproductive rate (Ro, intrinsic rate of natural increase (r m and the finite rate of increase (λ were estimated. A fertility life table is useful to select the most adequate factitious hosts for the

  11. Central venous catheter-related bacteremia due to Tsukamurella species in the immunocompromised host: a case series and review of the literature. (United States)

    Schwartz, M A; Tabet, S R; Collier, A C; Wallis, C K; Carlson, L C; Nguyen, T T; Kattar, M M; Coyle, M B


    We report 6 cases of bacteremia due to Tsukamurella species, all of which were in immunosuppressed patients with indwelling central venous catheters (CVCs). Fewer than 20 cases of serious illness due to these gram-positive bacilli have been reported in the medical literature; these cases have mostly been ascribed to the species Tsukamurella paurometabola. Tsukamurella species are frequently misidentified as Rhodococcus or Corynebacterium species. We used high-performance liquid chromatography to identify these organisms to the genus level and 16S ribosomal RNA gene sequencing and DNA-DNA dot blots for species identification. Three of our isolates were identified as Tsukamurella pulmonis, 1 was identified as Tsukamurella tyrosinosolvans, and 1 was identified as a unique species. One isolate was not maintained long enough for species identification. All patients were successfully treated with antimicrobial therapy and CVC removal. Infection with this organism should be considered in the immunosuppressed patient with an indwelling CVC and gram-positive bacilli in the blood.

  12. HostPhinder: A Phage Host Prediction Tool

    Directory of Open Access Journals (Sweden)

    Julia Villarroel


    Full Text Available The current dramatic increase of antibiotic resistant bacteria has revitalised the interest in bacteriophages as alternative antibacterial treatment. Meanwhile, the development of bioinformatics methods for analysing genomic data places high-throughput approaches for phage characterization within reach. Here, we present HostPhinder, a tool aimed at predicting the bacterial host of phages by examining the phage genome sequence. Using a reference database of 2196 phages with known hosts, HostPhinder predicts the host species of a query phage as the host of the most genomically similar reference phages. As a measure of genomic similarity the number of co-occurring k-mers (DNA sequences of length k is used. Using an independent evaluation set, HostPhinder was able to correctly predict host genus and species for 81% and 74% of the phages respectively, giving predictions for more phages than BLAST and significantly outperforming BLAST on phages for which both had predictions. HostPhinder predictions on phage draft genomes from the INTESTI phage cocktail corresponded well with the advertised targets of the cocktail. Our study indicates that for most phages genomic similarity correlates well with related bacterial hosts. HostPhinder is available as an interactive web service [1] and as a stand alone download from the Docker registry [2].

  13. Mitochondrial COI and morphological evidence for host specificity of the black cherry aphids Myzus cerasi (Fabricius, 1775 collected from different cherry tree species in Europe (Hemiptera, Aphididae

    Directory of Open Access Journals (Sweden)

    Rimantas Rakauskas


    Full Text Available Partial sequences of the mitochondrial COI gene of forty eight European and two Turkish population samples of Myzus cerasi from different winter hosts (Prunus spp. were subjected to phylogenetic analyses. The analysed M. cerasi samples emerged as paraphyletic relative to a Myzus borealis sample used as an out-group, and formed two major clades in neighbor joining, maximum parsimony, maximum likelihood and Bayesian inference trees, corresponding to subspecies living specifically on Prunus avium and P. cerasus. Multivariate discriminant analysis (method of canonical variates was applied to find out if morphological variation of samples correlated with mitochondrial COI and host plant information. Mean scores on the first two canonical variables clustered samples fully in accordance with their COI haplotypes and host plants confirming the existence of two morphologically similar winter host - specific subspecies of M.cerasi in Europe. No single morphological character enabled satisfactory discrimination between apterous viviparous females of the two subspecies. A three-character linear discriminant function enabled 92.37% correct identification of apterous viviparous females of M. cerasi cerasi (n=118 and 93.64% of M. cerasi pruniavium (n=110. A key for the morphological identification of the two subspecies is presented and their taxonomic status is discussed.

  14. Habronyx Förster (Hymenoptera: Ichneumonidae: Anomaloninae) in Peru and Ecuador: three new species, a range extension, and a new host record. (United States)

    Alvarado, Mabel; Grados, Juan


    The ichneumonid genus Habronyx is recorded for the first time from Peru and Ecuador, and three new species are described and figured-Habronyx (Camposcopus) flavus Alvarado, new species, H. (Habronyx) nigrofasciata Alvarado, new species, and H. (H.) saqsaywaman Alvarado, new species. Hadronyx (H.) punensis is recorded for the first time in Peru. Habronyx (H.) nigrofasciata was reared from Paracles tapina (Dyar, 1913) (Erebidae: Arctiinae). In addition, the distribution of P. tapina is expanded and figures of its larvae, pupae, and adult female and male are provided.

  15. Molecular and Morphological Characterization of Fasciola spp. Isolated from Different Host Species in a Newly Emerging Focus of Human Fascioliasis in Iran


    Reza Shafiei; Bahador Sarkari; Seyed Mahmuod Sadjjadi; Gholam Reza Mowlavi; Abdolali Moshfe


    The current study aimed to find out the morphometric and genotypic divergences of the flukes isolated from different hosts in a newly emerging focus of human fascioliasis in Iran. Adult Fasciola spp. were collected from 34 cattle, 13 sheep, and 11 goats from Kohgiluyeh and Boyer-Ahmad province, southwest of Iran. Genomic DNA was extracted from the flukes and PCR-RFLP was used to characterize the isolates. The ITS1, ITS2, and...

  16. A new species of microphallid (Trematoda: Digenea) infecting a novel host family, the Muraenidae, on the northern Great Barrier Reef, Australia. (United States)

    Kudlai, Olena; Cribb, Thomas H; Cutmore, Scott C


    A new species of microphallid, Longiductotrema tethepae n. sp., is reported from a muraenid eel Gymnothorax pseudothyrsoideus (Bleeker) on the northern Great Barrier Reef. The new species is described based on adults from Gy. pseudothyrsoideus and metacercariae from a grapsid crab, Grapsus albolineatus Latreille in Milbert, collected from off Lizard Island, Queensland, Australia. The new species is assigned to Longiductotrema Deblock & Heard, 1969 based on morphological characters (presence of a cirrus-sac; a long metraterm, intensively ensheathed by gland-cells; an entirely postcaecal uterus; vitellarium composed of two lateral clusters each of about ten follicles, situated in the testicular and post-testicular areas). Longiductotrema tethepae n. sp. is the third species assigned to the genus, differing from its congeners in having a distinctly larger body dimensions, a smaller pharynx in relation to oral sucker, the anterior limits of the vitelline fields at the level of the testes (vs at the level of the ovary) and in its parasitism of a muraenid fish (vs birds). Additionally, the new species differs from L. floridense Deblock & Heard, 1969 in having a shorter metraterm and from L. scandolensis Deblock & Bartoli, 1988 in having a less elongate forebody in relation to body length, shorter caeca and prepharynx, and slightly larger eggs. Phylogenetic analyses, based on partial 28S rRNA gene sequences, showed that the present species is sister to all other microphallids for which sequence data are available. This is the fourth report of a microphallid from a marine eel, the first from the Muraenidae Rafinesque and the first from a marine fish in the Indo-west Pacific. A summary of all species of the Microphallidae parasitising fish is provided.

  17. Eriophyes species (Acari: Eriophyoidea) inhabiting lime trees (Tilia spp.: Tiliaceae)--supplementary description and morphological variability related to host plants and female forms. (United States)

    Soika, Grazyna; Kozak, Marcin


    Three poorly known species of the subfamily Eriophyinae living on Tilia spp. (Tiliaceae) are illustrated and supplementary descriptions are provided. Two of them, Eriophyes exilis (Nalepa 1892) and Eriophyes nervalis (Nalepa 1918), were recorded both in vein angle galls on leaves of Tilia platyphyllos Scop. and in erinea on leaves of Tilia tomentosa Moench, Tilia americana L. 'Moltkei', Tilia americana var. heterophylla (Vent.) Loudon, Tilia cordata Mill., Tiliajaponica (Miq.) Simonk., Tilia petiolaris DC. and Tilia zamoyskiana Wr6bl. The third species, Eriophyes tiliae Nalepa 1890, was found in nail galls on leaves of T platyphyllos, T americana and T. cordata. All of these Eriophyes species showed noticeable morphological differences between protogyne and deutogyne females in terms of the number of dorsal annuli, location of setae d, length of setae e and 3a, distance between tubercles 3a and the length and pattern of the prodorsal shield. Based on a comparative morphological analysis of this original data with that published by A. Nalepa, new synonyms for the following species are proposed: Erophyes exilis (Nalepa) = Eriophyes leiosoma Nalepa syn. nov.; Eriophyes nervalis (Nalepa) = Eriophyes tiliaceus Nalepa syn. nov., Eriophyes tiliae Nalepa = Eriophyes rudis Nalepa syn. nov. = Eriophyes tomentosae Nalepa syn. nov. A key to all studied Eriophyes species living on lime trees is included.

  18. A novel technique based on the ratio of potentio-charge capacity to galvano-charge capacity (RPG) for determination of the diffusion coefficient of intercalary species within insertion-host materials: theories and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Xincun Tang; Chunyue Pan [Central South Univ., College of Chemistry and Chemical Engineering, Changsha (China); Liping He; Zongzhang Chen [Hunan Univ., College of Chemistry and Chemical Engineering, Changsha (China); Liqing Li [Hunan Univ., Dept. of Environmental Science and Engineering, Changsha (China)


    The diffusion process of intercalary species within insertion-host materials is the key step during the whole electrode reaction. Here a novel method based on the ratio (q) of the potentio-charge capacity to the galvano-charge capacity (RPG) was developed to determine the diffusion coefficient of intercalary species for porous electrode by the spherical diffusion model. By the RPG method, the Li{sup +} diffusion coefficients within graphite were determined from the galvano-potentio-charge curves. The values of diffusion coefficient measured at different galvano-charge current or at different cutoff voltage suggested that the RPG method has a good reliability for determination of the diffusion coefficient. (Author)

  19. [Epidemiological data on human distomatosis (Fasciola hepatica L.) in the Limousin region of France. The species of plants eaten and snail hosts]. (United States)

    Rondelaud, D


    These epidemiological studies concern 187 cases of human fasciolasis which occurred in the region of Limousin, France on a period of 24 years. Four species of plants have been eaten: Nasturtium officinale, Roripa silvestris, Taraxacum gr. officinale, Valerianella olitoria. These plants have been eaten during all months of the year, but with higher numbers in July-August and from November to February. The cases of human fasciolasis almost take place on all years, but their numbers are high in years showing a very important infestation of cattle by Fasciola hepatica. In 2/3 of cases, the plants come from stations situated out of cattle pastures. The water-cress almost comes from natural stations or from familial plantations. Five species of snails have been observed in these stations: Lymnaea glabra, L. palustris, L. peregra, L. stagnalis, L. truncatula. The young snails of these species experimentally have been observed. The significance of these results is discussed.

  20. The first record of Baccharis L. (Asteraceae) as a host-plant genus for Nepticulidae (Lepidoptera), with description of new Stigmella species from South America. (United States)

    Stonis, Jonas R; Diškus, Arūnas; Remeikis, Andrius; Remeikis, Andrius; Davis, Donald R; Solis, M Alma; Torres, Nixon Cumbicus


    We record the first Nepticulidae species found to feed on Baccharis L. (Asteraceae). Despite the high species richness of Baccharis in the Western Hemisphere, no nepticulid has ever been recorded feeding on Baccharis. In this paper we describe six new Stigmella Schrank species feeding on Baccharis: S. emarginatae Diškus & Stonis, sp. nov., S. bipartita Diškus & Stonis, sp. nov., S. tripartita Diškus & Stonis, sp. nov., S. latifoliae Remeikis, Diškus & Stonis, sp. nov., S. baccharicola Diškus & Stonis, sp. nov., and S. confertae Diškus & Stonis, sp. nov. The remaining two taxa are left unnamed. All taxa are illustrated with photographs of adults, their genitalia, and their leaf-mines. Additionally, leaf-mines on Baccharis salicifolia are documented.

  1. Meagre Argyrosomus regius (Osteichthyes) as host of a gonad-infecting species of Philometra (Nematoda: Philometridae) off the Atlantic coast of Portugal. (United States)

    Moravec, Frantisek; Prista, Nuno; Costa, Maria José


    Subgravid females (up to 439 mm long) of the nematode Philometra sp. were found in meagre Argyrosomus regius (Asso, 1801) (Sciaenidae: Perciformes) off the southern Atlantic coast of Portugal in 2006. The general morphology of these nematodes somewhat resembles that of Philometra lateolabracis (Yamaguti, 1935), but the gravid females of the species from A. regius are apparently much longer. This is the first documented record of a gonad-infecting species of Philometra in marine fishes off the Atlantic coast of Europe. The possible importance of the gonad-parasitizing Philometra spp. as pathogens of marine fishes is stressed.

  2. A new cryptic species of Diatraea (Lepidoptera: Crambidae: Crambinae) feeding on eastern gama grass and a novel host association with a braconid (Hymenoptera) in the United States (United States)

    The genus Diatraea currently consists of seven species in the United States, including Diatraea crambidoides (Grote), an economic pest of corn. Larvae of D. crambidoides are also reported to feed on sorghum (Sorghum bicolor (L.) Moench.), Johnsongrass (Sorghum halepense (L.) Pers.), sugar cane (Sacc...

  3. Effect of curtovirus species competitiveness in host plants on transmission and incidence of Beet severe curly top virus and Beet mild curly top virus (United States)

    Curly top disease, caused by viruses in the genus Curtovirus, causes significant economic losses for sugarbeet and other crops throughout the western United States. Recent studies demonstrated the two most abundant curtovirus species in the US are Beet severe curly top virus (BSCTV) and Beet mild c...

  4. Minimal standards for describing new host-associated species belonging to the families Campylobacteraceae and Helicobacteraceae: Campylobacter, Arcobacter, Helicobacter and Wolinella spp (United States)

    Ongoing changes in taxonomic methods, and in the rapid development of the taxonomic structure of species assigned to the Epsilonproteobacteria have lead the International Committee of Systematic Bacteriology Subcommittee on the Taxonomy of Campylobacter and Related Bacteria to discuss significant up...

  5. The weevil genus Achia champion (Coleoptera: Curculionidae): new species associate with urvillea (Sapindaceae) and New Serjania Host Plant records for A. ancile Burke and A. affinis Hustache (United States)

    Three new species of the weevil genus Achia Champion are described: A. urvilleae Clark and Burke from the state of Santa Catarina, Brazil and Misiones Province, Argentina; A. uniformis Clark and Burke from Bolivia; and A. boliviana Clark and Burke from Bolivia and Salta and Santiago del Estero prov...

  6. The desert tortoise trichotomy: Mexico hosts a third, new sister-species of tortoise in the Gopherus morafkai–G. agassizii group (United States)

    Edwards, Taylor; Karl, Alice E.; Vaughn, Mercy; Rosen, Philip C.; Torres, Cristina Meléndez; Murphy, Robert W.


    Abstract Desert tortoises (Testudines; Testudinidae; Gopherus agassizii group) have an extensive distribution throughout the Mojave, Colorado, and Sonoran desert regions. Not surprisingly, they exhibit a tremendous amount of ecological, behavioral, morphological and genetic variation. Gopherus agassizii was considered a single species for almost 150 years but recently the species was split into the nominate form and Morafka’s desert tortoise, Gopherus morafkai, the latter occurring south and east of the Colorado River. Whereas a large body of literature focuses on tortoises in the United States, a dearth of investigations exists for Mexican animals. Notwithstanding, Mexican populations of desert tortoises in the southern part of the range of Gopherus morafkai are distinct, particularly where the tortoises occur in tropical thornscrub and tropical deciduous forest. Recent studies have shed light on the ecology, morphology and genetics of these southern ‘desert’ tortoises. All evidence warrants recognition of this clade as a distinctive taxon and herein we describe it as Gopherus evgoodei sp. n. The description of the new species significantly reduces and limits the distribution of Gopherus morafkai to desertscrub habitat only. By contrast, Gopherus evgoodei sp. n. occurs in thornscrub and tropical deciduous forests only and this leaves it with the smallest range of the three sister species. We present conservation implications for the newly described Gopherus evgoodei, which already faces impending threats. PMID:27006625

  7. Host-derived pentapeptide affecting adhesion, proliferation, and local pH in biofilm communities composed of Streptococcus and Actinomyces species

    DEFF Research Database (Denmark)

    Drobni, M.; Li, T.; Krüger, C.


    Salivary proline-rich proteins (PRPs) attach commensal Actinomyces and Streptococcus species to teeth. Here, gel filtration, mass spectrometry and Edman degradation were applied to show the release of a pentapeptide, RGRPQ, from PRP-1 upon proteolysis by Streptococcus gordonii. Moreover, synthetic...

  8. Host population genetic structure and zooxanthellae diversity of two reef-building coral species along the Florida Reef Tract and wider Caribbean (United States)

    Baums, I. B.; Johnson, M. E.; Devlin-Durante, M. K.; Miller, M. W.


    In preparation for a large-scale coral restoration project, we surveyed host population genetic structure and symbiont diversity of two reef-building corals in four reef zones along the Florida reef tract (FRT). There was no evidence for coral population subdivision along the FRT in Acropora cervicornis or Montastraea faveolata based on microsatellite markers. However, in A. cervicornis, significant genetic differentiation was apparent when extending the analysis to broader scales (Caribbean). Clade diversity of the zooxanthellae differed along the FRT. A. cervicornis harbored mostly clade A with clade D zooxanthellae being prominent in colonies growing inshore and in the mid-channel zones that experience greater temperature fluctuations and receive significant nutrient and sediment input. M. faveolata harbored a more diverse array of symbionts, and variation in symbiont diversity among four habitat zones was more subtle but still significant. Implications of these results are discussed for ongoing restoration and conservation work.

  9. Morphological and molecular characterization of a new species of leech (Glossiphoniidae, Hirudinida: Implications for the health of its imperiled amphibian host (Cryptobranchus alleganiensis

    Directory of Open Access Journals (Sweden)

    William A. Hopkins


    Full Text Available The hellbender (Cryptobranchus alleganiensis is among the most intriguing and imperiled amphibians in North America. Since the 1970s and 80s, western populations of the Ozark and eastern subspecies in Missouri have declined by nearly 80%. As a result of population declines, the Ozark hellbender was recently federally protected as an endangered species, and the eastern subspecies was granted protection under CITES. Although habitat degradation is probably the biggest threat to hellbender populations, recent evidence suggests that pathogens including chytrid fungus and “flesh-eating” bacteria may also contribute to declines in Ozark hellbenders. Leeches, which are very common on Ozark hellbenders, have recently been implicated as possible vectors of disease among Ozark hellbenders but have not been described in eastern hellbenders or outside of Missouri and Arkansas. We discovered a population of leeches on eastern hellbenders in southwest Virginia and confirmed that the species of leech is within the genus Placobdella, but is morphologically and genetically distinct from all previously described leech species. We named the new species Placobdella appalachiensis sp. n. Moser and Hopkins, based on the mountainous region in which it was discovered. Our surveys over a three consecutive year period suggested that this leech species may be patchily distributed and/or have a narrow geographic range. We consistently detected leeches at one site (mean prevalence in 80 hellbenders = 27.5%; median intensity = 3.0 leeches per parasitized hellbender [range 1 - >250 leeches] during three years of surveys, but we never found leeches in any of our other seven study sites in two streams (mean prevalence in 139 hellbenders = 0%. We found a significant positive relationship between hellbender body size and the intensity of parasitism, and we suggest the possibility that the behavioral ecology of adults leading up to reproduction may increase their encounter

  10. Oogonial biometry and phylogenetic analyses of the Pythium vexans species group from woody agricultural hosts in South Africa reveal distinct groups within this taxon. (United States)

    Spies, Christoffel F J; Mazzola, Mark; Botha, Wilhelm J; Van Der Rijst, Marieta; Mostert, Lizel; Mcleod, Adéle


    Pythium vexans fits into the internal transcribed spacer (ITS) clade K sensu Lévesque & De Cock (2004). Within clade K, P. vexans forms a distinct clade containing two enigmatic species, Pythium indigoferae and Pythium cucurbitacearum of which no ex-type strains are available. In South Africa, as well as in other regions of the world, P. vexans isolates are known to be heterogeneous in their ITS sequences and may consist of more than one species. This study aimed to investigate the diversity of South African P. vexans isolates, mainly from grapevines, but also citrus and apple using (i) phylogenetic analyses of the ITS, cytochrome c oxidase (cox) I, cox II, and β-tubulin regions and (ii) seven biometric oogonial parameters. Each of the phylogenies clustered P. vexans isolates into a single well-supported clade, distinct from other clade K species. The β-tubulin region was phylogenetically uninformative regarding the P. vexans group. The ITS phylogeny and combined cox I and II phylogenies, although each revealing several P. vexans subclades, were incongruent. One of the most striking incongruences was the presence of one cox subclade that contained two distinct ITS subclades (Ib and IV). Three groups (A-C) were subjectively identified among South African P. vexans isolates using (i) phylogenetic clades (ITS and cox), (ii) univariate analysis of oogonial diameters, and (iii) multivariate analyses of biometric oogonial parameters. Group A is considered to be P. vexans s. str. since it contained the P. vexans CBS reference strain from Van der Plaats-Niterink (1981). This group had significantly smaller oogonial diameters than group B and C isolates. Group B contained the isolates from ITS subclades Ib and IV, which formed a single cox subclade. The ITS subclade IV isolates were all sexually sterile or produced mainly abortive oospores, as opposed to the sexually fertile subclade Ib isolates, and may thus represent a distinct assemblage within group B. Although ITS

  11. Sea lamprey mark type, wounding rate, and parasite-host preference and abundance relationships for lake trout and other species in Lake Ontario (United States)

    Lantry, Brian F.; Adams, Jean; Christie, Gavin; Schaner, Teodore; Bowlby, James; Keir, Michael; Lantry, Jana; Sullivan, Paul; Bishop, Daniel; Treska, Ted; Morrison, Bruce


    We examined how attack frequency by sea lampreys on fishes in Lake Ontario varied in response to sea lamprey abundance and preferred host abundance (lake trout > 433 mm). For this analysis we used two gill net assessment surveys, one angler creel survey, three salmonid spawning run datasets, one adult sea lamprey assessment, and a bottom trawl assessment of dead lake trout. The frequency of fresh sea lamprey marks observed on lake trout from assessment surveys was strongly related to the frequency of sea lamprey attacks observed on salmon and trout from the creel survey and spawning migrations. Attack frequencies on all salmonids examined were related to the ratio between the abundances of adult sea lampreys and lake trout. Reanalysis of the susceptibility to sea lamprey attack for lake trout strains stocked into Lake Ontario reaffirmed that Lake Superior strain lake trout were among the most and Seneca Lake strain among the least susceptible and that Lewis Lake strain lake trout were even more susceptible than the Superior strain. Seasonal attack frequencies indicated that as the number of observed sea lamprey attacks decreased during June–September, the ratio of healing to fresh marks also decreased. Simulation of the ratios of healing to fresh marks indicated that increased lethality of attacks by growing sea lampreys contributed to the decline in the ratios and supported laboratory studies about wound healing duration.

  12. Systematics, host plants, and life histories of three new Phyllocnistis species from the central highlands of Costa Rica (Lepidoptera, Gracillariidae, Phyllocnistinae

    Directory of Open Access Journals (Sweden)

    Akito Kawahara


    Full Text Available Three new species of Phyllocnistis Zeller are described from the central highlands of Costa Rica: Phyllocnistis drimiphaga sp. n., P. maxberryi sp. n., and P. tropaeolicola sp. n. Larvae of all three are serpentine leaf miners. Phyllocnistis drimiphaga feeds on Drimys granadensis (Winteraceae, P. maxberryi on Gaiadendron punctatum (Loranthaceae, and P. tropaeolicola on Tropaeolum emarginatum (Tropaeolaceae. All specimens were collected as larvae or pupae in their mines and reared in captivity. Parasitoid wasps were reared from P. drimiphaga and P. maxberryi. Description of the adults, pupae, and life histories are supplemented with photographs, illustrations, and scanning electron micrographs.

  13. Molecular analysis of clonal trichomonad isolates indicate the existence of heterogenic species present in different birds and within the same host. (United States)

    Grabensteiner, Elvira; Bilic, Ivana; Kolbe, Thomas; Hess, Michael


    Trichomonas gallinae is a flagellated protozoon and the etiological agent of avian trichomoniasis. Despite its importance, especially in columbiformes and falconiformes, only a few molecular studies have yet been performed in order to investigate the degree of genetic diversity and cross-transmissibility between different isolates of this parasite. To address these questions 63 clonal cultures of Trichomonas spp. isolates were established by successful isolation of single trichomonads from a mixture of micro-organisms obtained from 17 birds belonging to five different species. All birds were from Austria with the exception of one bird which originated from the Czech Republic. The sequence of the complete genomic region spanning the two ribosomal RNA internal transcribed spacers (ITS1 and ITS2) and the 5.8S rRNA gene was determined for all 63 isolates. In addition, in order to compare the results obtained with the ITS1-5.8S-ITS2 region the sequence of the 18S rRNA gene was determined from a subset of isolates. Unrooted phylogenetic trees inferred by distance, parsimony, and likelihood methods suggest the existence of at least three clusters within the T. gallinae species complex, two groups being closely related to the human pathogens, Trichomonas vaginalis and Trichomonas tenax. Furthermore, for the first time two different trichomonad sequence types isolated at the same time from a single bird could be detected in the crops of two pigeons. (c) 2010 Elsevier B.V. All rights reserved.

  14. Investigation on species of freshwater crabs-the second intermediate host of paragonimus westermanii%肺吸虫第二中间宿主淡水溪蟹种类调查

    Institute of Scientific and Technical Information of China (English)

    周腾坚; 洪加林; 陈海强


    Objective:To investigate the species and distribution of freshwater crabs,the second imermediate host of paragonimus westermanii in Yongjia county.Methods:The freshwater crabs in Yongjia county were collected by field-investigation for morphology identification to discover new species.Results:There were four major kinds of freshwater crabs in Yongjia county,composed by S.chekiangense,S.yangtsekiense,Nanhaipotamon and Bottapotamon.And the Nanhaipotamon and Bottapotamon were new species.Conclusion:It proves that new species of freshwater crabs existed in Yongjia county,so awareness of the species,infection rate and changes of freshwater crabs can help study the life history of paragonimus westermanii and provide etiological basis for prevention and control of paragonimiasis.%目的:调查永嘉县肺吸虫第二中间宿主淡水溪蟹的种类与分布情况.方法:通过实地考察,捕捉分布于永嘉县境内的淡水溪蟹,并进行形态学鉴定,以期发现新蟹种.结果:分类显示目前永嘉县淡水溪蟹类主要为浙江华溪蟹、长江华溪蟹、南海溪蟹和博特溪蟹,其中南海溪蟹和博特溪蟹为新发现蟹种.结论:永嘉县存在淡水溪蟹新种属,了解溪蟹及其囊蚴感染率与变迁,有助于肺吸虫生活史的研究,能为防治肺吸虫病提供可靠的病原学依据.

  15. Antimicrobial activity of cathelicidins BMAP28, SMAP28, SMAP29, and PMAP23 against Pasteurella multocida is more broad-spectrum than host species specific. (United States)

    Brogden, Kim A; Nordholm, Gwen; Ackermann, Mark


    The antimicrobial activity of linear, cationic alpha-helical peptides from cattle (BMAP28), sheep (SMAP28 and SMAP29), and pigs (PMAP23) were assessed to determine if activity was selective for Pasteurella multocida from a particular animal species or broad-spectrum against all P. multocida tested. The antimicrobial activities of synthetic peptides were determined for P. multocida isolated from cattle (10 isolates), sheep (10 isolates), and pigs (10 isolates) in a broth microdilution assay. All thirty isolates of P. multocida were susceptible to BMAP28 (MICs and MBCs, 1.0-1.9 microM); SMAP28 and SMAP29 (MICs and MBCs, 0.2-0.7 microM); and PMAP23 (MICs and MBCs, 4.3 to > or = 6.8 microM). Overall, the results of this study suggest that synthesized cathelicidins from cattle, sheep, and pigs had broad-spectrum antimicrobial activity against all P. multocida.

  16. Two new species of coccidia (Apicomplexa: Eimeriidae) from leaf-tailed geckos, Uroplatus spp. (Sauria: Gekkonidae) from Madagascar, including a new host of Eimeria brygooi Upton & Barnard, 1987. (United States)

    McAllister, Chris T; Scott Seville, R; Hartdegen, Ruston


    During May and June 2015, four common leaf-tailed geckos, Uroplatus fimbriatus (Schneider), five satanic leaf-tailed geckos, Uroplatus phantasticus (Boulenger), and four mossy leaf-tailed geckos, Uroplatus sikorae Boettger originally collected from Madagascar and housed at the Dallas Zoo, USA, had their faeces examined for coccidian parasites. Eight (62%) geckos were found to be passing oöcysts, including a new eimerian, a new isosporan and a previously described eimerian. Three of four (75%) U. fimbratus (type-host) and one of five (20%) U. phantasticus were infected with Eimeria schneideri n. sp.; oöcysts were subspheroidal to ellipsoidal with a bi-layered wall and measured (mean length × width, L × W) 15.1 × 13.5 µm, with a length/width (L/W) ratio of 1.1. A micropyle and oöcyst residuum were absent but one to many polar granules were present. Sporocysts were ovoidal, 6.9 × 5.3 µm, L/W = 1.3. Stieda, sub-Stieda and para-Stieda bodies were absent. A globular sporocyst residuum was present as dispersed granules. Four of five (80%) U. phantasticus harboured Isospora boulengeri n. sp.; oöcysts were subpheroidal to ellipsoidal with a bi-layered wall and measured 17.3 × 16.0 µm, L/W = 1.1. A micropyle and oöcyst residuum were absent but a polar granule was present. Sporocysts were ellipsoidal, 9.5 × 6.9 µm, L/W = 1.4. Stieda and sub-Stieda bodies were present but a para-Stieda body was absent. A globular sporocyst residuum was present with dispersed granules. In addition, one of four (25%) U. sikorae was infected with an eimerian indistinguishable from Eimeria brygooi Upton & Barnard, 1987, previously reported from Madagascar day gecko, Phelsuma grandis Gray and golddust day gecko, Phelsuma laticauda (Boettger) from Madagascar. These are the first coccidians described from Uroplatus spp.

  17. Mercury species in dab (Limanda limanda) from the North Sea, Baltic Sea and Icelandic waters in relation to host-specific variables. (United States)

    Lang, Thomas; Kruse, Reinhard; Haarich, Michael; Wosniok, Werner


    In the framework of the ICON project (Integrated Assessment of Contaminant Impacts on the North Sea), muscle tissue from a total of 135 common dab (Limanda limanda) (20-28 cm total length) was collected in seven offshore sampling areas in the North Sea, at Iceland and in the Baltic Sea during Aug/Sept and December 2008 for a chemical mercury speciation analysis by means of gas chromatography and detection by cold vapour atomic fluorescence spectroscopy (GC-CVAFS). There was a highly significant correlation between concentrations of methylmercury (MeHg(+)) and inorganic mercury (Hg(2+)) in individual fish, and the mean ratio of MeHg(+) compared to Σ Hg (MeHg(+) + Hg(2+)) was 94.0%. The results revealed statistically significant differences in concentrations of MeHg(+) and Hg(2+), respectively, between sampling areas. Mean concentrations in the German Bight (North Sea), in Icelandic waters and in Mecklenburg Bight (Baltic Sea) were low (MeHg(+): 0.023-0.036; Hg(2+): 0.001-0.002 mg/kg wet weight), while concentrations in dab from the Dogger Bank, Firth of Forth and the vicinity of the Ekofisk oil field (all North Sea) were significantly higher (MeHg(+): 0.059-0.101; Hg(2+): 0.003-0.004 mg/kg wet weight). Statistical correlation analysis on effects of host-specific factors revealed that neither length, weight, age, sex nor condition factor showed a significant relationship with Hg concentrations. However, Hg concentrations were significantly correlated with the Fish Disease Index (FDI), indicating a relationship between Hg concentrations and the health status of dab. Multiple linear regression analysis aiming to find factors affecting Hg concentrations revealed that only the sampling area had a highly significant main effect on Hg concentrations, and in some cases, additionally the condition factor contributed significantly to the final model. From the results, it cannot be excluded that elevated Hg concentration recorded in dab were linked to discharges from

  18. The Role of Within-Host Competition for Coexistence in Multiparasitoid-Host Systems. (United States)

    van Velzen, Ellen; Pérez-Vila, Saleta; Etienne, Rampal S


    Multiparasitism (females of multiple species parasitizing the same host) is a ubiquitous phenomenon in parasitoids, yet the role of within-host competition has been mostly ignored in multiparasitoid-host models. Here we study the effect of varying the degree of competition at different life stages: competition over oviposition sites (between-adult competition) and larval competition over resources within the host (within-host competition). We adapt a Nicholson-Bailey model to allow for varying levels of between-adult competition (varying the overlap in species distributions) and within-host competition (varying the number of offspring that can successfully emerge from a host). Surprisingly, while stronger between-adult competition reduces coexistence, stronger within-host competition promotes it. Asymmetric between-adult competition (a fecundity difference between the two species) reduces coexistence when compared to symmetric competition; this can be counteracted by asymmetric within-host competition (within-host competitive advantage of the lower-fecundity species), but only when within-host competition is strong and the correlation between the parasitoids' distributions is intermediate. We discuss our results in the context of the interaction between two parasitoid species, Nasonia vitripennis and Nasonia giraulti, which have strongly correlated distributions and high levels of multiparasitism in the field. We conclude that either low or asymmetric within-host competition is unlikely to explain their coexistence.

  19. Bottom-up effects of host-plant species diversity and top-down effects of ants interactively increase plant performance. (United States)

    Moreira, Xoaquín; Mooney, Kailen A; Zas, Rafael; Sampedro, Luis


    While plant diversity is well known to increase primary productivity, whether these bottom-up effects are enhanced by reciprocal top-down effects from the third trophic level is unknown. We studied whether pine tree species diversity, aphid-tending ants and their interaction determined plant performance and arthropod community structure. Plant diversity had a positive effect on aphids, but only in the presence of mutualistic ants, leading to a threefold greater number of both groups in the tri-specific cultures than in monocultures. Plant diversity increased ant abundance not only by increasing aphid number, but also by increasing ant recruitment per aphid. The positive effect of diversity on ants in turn cascaded down to increase plant performance; diversity increased plant growth (but not biomass), and this effect was stronger in the presence of ants. Consequently, bottom-up effects of diversity within the same genus and guild of plants, and top-down effects from the third trophic level (predatory ants), interactively increased plant performance.

  20. Genetic characterisation of Fasciola samples from different host species and geographical localities revealed the existence of F. hepatica and F. gigantica in Niger. (United States)

    Ali, H; Ai, L; Song, H Q; Ali, S; Lin, R Q; Seyni, B; Issa, G; Zhu, X Q


    In the present study, 16 samples representing Fasciola (Platyhelminthes: Trematoda: Digenea) from sheep and cattle from seven geographical locations in Niger were characterized genetically by sequences of the first (ITS-1) and second (ITS-2) internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA). The ITS rDNA was amplified from individual liver flukes by polymerase chain reaction (PCR), and the amplicons were sequenced directly. The lengths of the ITS-1 and ITS-2 sequences were 422 and 361/362 bp, respectively, for all liver fluke samples sequenced. Comparison of the ITS sequences of the Niger Fasciola samples examined in the present study with that of Fasciola hepatica, Fasciola gigantica, and the "intermediate Fasciola" from elsewhere revealed that the Niger Fasciola samples examined represent two species, namely F. hepatica and F. gigantica. This is the first demonstration of the existence of both F. hepatica and F. gigantica in Niger by a genetic approach, which provides foundation for further studies on F. hepatica and F. gigantica in Niger and has implications for studying the population genetic structure of the Niger Fasciola and for the diagnosis and control of the disease they cause.

  1. The effect of host plant species on the development ofTrabala vishnou gigantina Yang (Lepidoptera:Lasiocampidae)%栎黄枯叶蛾生长发育与几种寄主内含物的关系

    Institute of Scientific and Technical Information of China (English)

    温冬梅; 刘永华; 任利利; 陆鹏飞; 骆有庆


    【目的】探讨饲喂不同寄主植物对栎黄枯叶蛾Trabala vishnou gigantina Yang生长发育及繁殖的影响,分析寄主植物内含物与其生长发育及繁殖的关系,为研究不同寄主植物对栎黄枯叶蛾种群动态的影响提供理论依据。【方法】在室内条件下,利用沙棘Hippophae rhamnoides、山杏Armeniaca sibirica、山杨Populus davidiana、旱柳Salix matsudana饲养该虫,观察幼虫发育历期、蛹历期、蛹重及产卵量等指标,同时测定寄主叶片中可溶性糖、可溶性蛋白质、水分、单宁及黄酮的含量,并进行线性回归分析。【结果】不同寄主植物饲喂栎黄枯叶蛾幼虫的发育历期、蛹历期、蛹重及产卵量均存在显著差异。取食沙棘的幼虫历期最短,仅为(74.50±1.76)d,而取食旱柳历期最长,达(106.00±1.51)d。取食山杨的蛹历期最长,为(44.00±1.41)d,最短的是取食旱柳的,仅为(32.70±3.13)d。饲喂沙棘和山杏的雌、雄蛹重和成虫产卵量显著高于饲喂山杨和旱柳的。对不同寄主的营养物质、次生物质和水分含量测定结果表明:不同寄主间营养物质、次生物质与水分的含量差异显著。回归相关分析表明:幼虫发育历期与寄主植物可溶性蛋白质含量呈显著负相关;雌蛹重和产卵量与寄主植物可溶性糖含量呈显著负相关;雌、雄蛹重与寄主植物含水量呈显著正相关;蛹历期与单宁含量呈显著正相关,但黄酮含量的高低与栎黄枯叶蛾生长发育等指标无相关性。【结论】沙棘是栎黄枯叶蛾生长发育及繁殖的最适寄主植物;并且寄主植物中可溶性糖、单宁的含量低、含水量和可溶性蛋白质含量高有利于栎黄枯叶蛾的生长发育和繁殖。%Objectives] To examine the effects of feeding on different host plant species on the development of Trabala vishnou gigantina Yang,and determine the relative

  2. Southern plains woodrats (Neotoma micropus) from southern Texas are important reservoirs of two genotypes of Trypanosoma cruzi and host of a putative novel Trypanosoma species. (United States)

    Charles, Roxanne A; Kjos, Sonia; Ellis, Angela E; Barnes, John C; Yabsley, Michael J


    Trypanosoma cruzi, the causative agent of Chagas' disease, is an important public health and veterinary pathogen. Although human cases are rare in the United States, infections in wildlife, and in some areas domestic dogs, are common. In 2008 and 2010, we investigated T. cruzi prevalence in possible vertebrate reservoirs in southern Texas, with an emphasis on southern plains woodrats (Neotoma micropus). Infection status was determined using a combination of culture isolation, polymerase chain reaction (PCR), and serologic testing. Based on PCR and/or culture, T. cruzi was detected in 35 of 104 (34%) woodrats, 3 of 4 (75%) striped skunks (Mephitis mephitis), 12 of 20 (60%) raccoons (Procyon lotor), and 5 of 28 (18%) other rodents including a hispid cotton rat (Sigmodon hispidus), rock squirrel (Otospermophilus variegatus), black rat (Rattus rattus), and two house mice (Mus musculus). Additionally, another Trypanosoma species was detected in 41 woodrats, of which 27 were co-infected with T. cruzi. Genetic characterization of T. cruzi revealed that raccoon, rock squirrel, and cotton rat isolates were genotype TcIV, while woodrats and skunks were infected with TcI and TcIV. Based on the Chagas Stat-Pak assay, antibodies were detected in 27 woodrats (26%), 13 raccoons (65%), 4 skunks (100%), and 5 other rodents (18%) (two white-ankled mice [Peromyscus pectoralis laceianus], two house mice, and a rock squirrel). Seroprevalence based on indirect immunofluorescence antibody testing was higher for both woodrats (37%) and raccoons (90%), compared with the Chagas Stat-Pak. This is the first report of T. cruzi in a hispid cotton rat, black rat, rock squirrel, and white-ankled mouse. These data indicate that based on culture and PCR testing, the prevalence of T. cruzi in woodrats is comparable with other common reservoirs (i.e., raccoons and opossums) in the United States. However, unlike raccoons and opossums, which tend to be infected with a particular genotype, southern

  3. Host compatibility rather than vector-host-encounter rate determines the host range of avian Plasmodium parasites. (United States)

    Medeiros, Matthew C I; Hamer, Gabriel L; Ricklefs, Robert E


    Blood-feeding arthropod vectors are responsible for transmitting many parasites between vertebrate hosts. While arthropod vectors often feed on limited subsets of potential host species, little is known about the extent to which this influences the distribution of vector-borne parasites in some systems. Here, we test the hypothesis that different vector species structure parasite-host relationships by restricting access of certain parasites to a subset of available hosts. Specifically, we investigate how the feeding patterns of Culex mosquito vectors relate to distributions of avian malaria parasites among hosts in suburban Chicago, IL, USA. We show that Plasmodium lineages, defined by cytochrome b haplotypes, are heterogeneously distributed across avian hosts. However, the feeding patterns of the dominant vectors (Culex restuans and Culex pipiens) are similar across these hosts, and do not explain the distributions of Plasmodium parasites. Phylogenetic similarity of avian hosts predicts similarity in their Plasmodium parasites. This effect was driven primarily by the general association of Plasmodium parasites with particular host superfamilies. Our results suggest that a mosquito-imposed encounter rate does not limit the distribution of avian Plasmodium parasites across hosts. This implies that compatibility between parasites and their avian hosts structure Plasmodium host range.

  4. Local host specialization, host-switching, and dispersal shape the regional distributions of avian haemosporidian parasites. (United States)

    Ellis, Vincenzo A; Collins, Michael D; Medeiros, Matthew C I; Sari, Eloisa H R; Coffey, Elyse D; Dickerson, Rebecca C; Lugarini, Camile; Stratford, Jeffrey A; Henry, Donata R; Merrill, Loren; Matthews, Alix E; Hanson, Alison A; Roberts, Jackson R; Joyce, Michael; Kunkel, Melanie R; Ricklefs, Robert E


    The drivers of regional parasite distributions are poorly understood, especially in comparison with those of free-living species. For vector-transmitted parasites, in particular, distributions might be influenced by host-switching and by parasite dispersal with primary hosts and vectors. We surveyed haemosporidian blood parasites (Plasmodium and Haemoproteus) of small land birds in eastern North America to characterize a regional parasite community. Distributions of parasite populations generally reflected distributions of their hosts across the region. However, when the interdependence between hosts and parasites was controlled statistically, local host assemblages were related to regional climatic gradients, but parasite assemblages were not. Moreover, because parasite assemblage similarity does not decrease with distance when controlling for host assemblages and climate, parasites evidently disperse readily within the distributions of their hosts. The degree of specialization on hosts varied in some parasite lineages over short periods and small geographic distances independently of the diversity of available hosts and potentially competing parasite lineages. Nonrandom spatial turnover was apparent in parasite lineages infecting one host species that was well-sampled within a single year across its range, plausibly reflecting localized adaptations of hosts and parasites. Overall, populations of avian hosts generally determine the geographic distributions of haemosporidian parasites. However, parasites are not dispersal-limited within their host distributions, and they may switch hosts readily.

  5. Investigation of Host Species and Damage of Anoplophora glabripennis in Zhengzhou%郑州市光肩星天牛寄主植物种类及危害现状调查

    Institute of Scientific and Technical Information of China (English)

    丁鑫; 沈植国; 李永成; 程建明; 李高杨


    Urban landscape tree species in Zhengzhou vulnerably damaged by Anoplophora glabripennis were fully investigated in order to comprehensively understand the distribution and damage of A. Glabripennis in 2009 - 2010. The results showed that A. Glabripennis was distributed widely and had a significant spatial aggregation state. A. Glabripennis gathered more intensively in western and northern regions than in the eastern and south regions in Zhengzhou urban areas. Population density of A. Glabripennis showed a decreasing trend from west to east and from north to south in the same areas. The order of aggregation density was North > West > North Central> South Central > South >. East. The seriously damaged host plant species were willow > poplar>sycamore >acer mono. Willow with diameter at 1 m height more than 30 cm had the highest incidence, reaching 75. 24%. Sycamore with diameter at 1 m height less than 20 cm had the lowest incidence of 16. 82%. In the areas where various host plants were distributed, different hosts had significantly different damage levels. While in the areas where a single plant species was distributed, different individuals were not damaged at the same degree.%2009-2010年,对郑州市城市园林绿化常见树种中易受光肩星天牛危害的寄主植物进行全面调查,以了解郑州市光肩星天牛的分布及危害情况.调查发现,郑州市光肩星天牛分布广泛,有较为明显的空间聚集状态;市区西部、北部聚集区域光肩星天牛较东部、南部密集,虫口密度从西向东、由北往南呈递减趋势;聚集密度由大到小依次为:北部>西部>中北部>中南部>南部>东部.危害严重的树种依次为柳树>杨树>悬铃木>五角枫,其中米径30cm以上的柳树,虫株率最高,达到75.24%.米径20cm以下的悬铃木受危害较轻,虫株率为16.82%.多数杨树栽植时间长,树体高大,虫株率较高,而五角枫栽植面积及密度较小且分散,受危害

  6. Host plant quality mediates competition between arbuscular mycorrhizal fungi

    NARCIS (Netherlands)

    B. Knegt; J. Jansa; O. Franken; D.J.P. Engelmoer; G.D.A. Werner; H. Bücking; E.T. Kiers


    Arbuscular mycorrhizal fungi exchange soil nutrients for carbon from plant hosts. Empirical works suggests that hosts may selectively provide resources to different fungal species, ultimately affecting fungal competition. However, fungal competition may also be mediated by colonization strategies of

  7. Host plant quality mediates competition between arbuscular mycorrhizal fungi

    NARCIS (Netherlands)

    Knegt, B.; Jansa, J.; Franken, O.; Engelmoer, D.J.P.; Werner, G.D.A.; Bücking, H.; Kiers, E.T.


    Arbuscular mycorrhizal fungi exchange soil nutrients for carbon from plant hosts. Empirical works suggests that hosts may selectively provide resources to different fungal species, ultimately affecting fungal competition. However, fungal competition may also be mediated by colonization strategies of

  8. Host plant quality mediates competition between arbuscular mycorrhizal fungi

    NARCIS (Netherlands)

    Knegt, B.; Jansa, J.; Franken, O.; Engelmoer, D.J.P.; Werner, G.D.A.; Bücking, H.; Kiers, E.T.


    Arbuscular mycorrhizal fungi exchange soil nutrients for carbon from plant hosts. Empirical works suggests that hosts may selectively provide resources to different fungal species, ultimately affecting fungal competition. However, fungal competition may also be mediated by colonization strategies of

  9. Host conservatism or host specialization? Patterns of fungal diversification are influenced by host specificity in Ophiognomonia (Gnomoniaceae, Diaporthales) (United States)

    Species of Ophiognomonia (Gnomoniaceae) are perithecial fungi that occur as endophytes, pathogens, and latent saprobes on leaf and stem tissue of plants in the Betulaceae, Fagaceae, Juglandaceae, Lauraceae, Malvaceae, Platanaceae, Rosaceae, Salicaceae, and Sapindaceae. In this study host plant patte...

  10. Early-season host switching in Adelphocoris spp. (Hemiptera: Miridae of differing host breadth.

    Directory of Open Access Journals (Sweden)

    Hongsheng Pan

    Full Text Available The mirid bugs Adelphocoris suturalis (Jakovlev, Adelphocoris lineolatus (Goeze and Adelphocoris fasciaticollis (Reuter (Hemiptera: Miridae are common pests of several agricultural crops. These three species have vastly different geographical distributions, phenologies and abundances, all of which are linked to their reliance on local plants. Previous work has shown notable differences in Adelphocoris spp. host use for overwintering. In this study, we assessed the extent to which each of the Adelphocoris spp. relies on some of its major overwinter hosts for spring development. Over the course of four consecutive years (2009-2012, we conducted population surveys on 77 different plant species from 39 families. During the spring, A. fasciaticollis used the broadest range of hosts, as it was found on 35 plant species, followed by A. suturalis (15 species and A. lineolatus (7 species. Abundances of the species greatly differed between host plants, with A. fasciaticollis reaching the highest abundance on Chinese date (Ziziphus jujuba Mill., whereas both A. suturalis and A. lineolatus preferred alfalfa (Medicago sativa L.. The host breadths of the three Adelphocoris spp. differed greatly between subsequent spring and winter seasons. The generalist species exhibited the least host fidelity, with A. suturalis and A. lineolatus using 8 of 22 and 4 of 12 overwinter host species for spring development, respectively. By contrast, the comparative specialist A. fasciaticollis relied on 9 of its 11 overwinter plants as early-season hosts. We highlight important seasonal changes in host breadth and interspecific differences in the extent of host switching behavior between the winter and spring seasons. These findings benefit our understanding of the evolutionary interactions between mirid bugs and their host plants and can be used to guide early-season population management.

  11. Host plant adaptation in Drosophila mettleri populations.

    Directory of Open Access Journals (Sweden)

    Sergio Castrezana

    Full Text Available The process of local adaptation creates diversity among allopatric populations, and may eventually lead to speciation. Plant-feeding insect populations that specialize on different host species provide an excellent opportunity to evaluate the causes of ecological specialization and the subsequent consequences for diversity. In this study, we used geographically separated Drosophila mettleri populations that specialize on different host cacti to examine oviposition preference for and larval performance on an array of natural and non-natural hosts (eight total. We found evidence of local adaptation in performance on saguaro cactus (Carnegiea gigantea for populations that are typically associated with this host, and to chemically divergent prickly pear species (Opuntia spp. in a genetically isolated population on Santa Catalina Island. Moreover, each population exhibited reduced performance on the alternative host. This finding is consistent with trade-offs associated with adaptation to these chemically divergent hosts, although we also discuss alternative explanations for this pattern. For oviposition preference, Santa Catalina Island flies were more likely to oviposit on some prickly pear species, but all populations readily laid eggs on saguaro. Experiments with non-natural hosts suggest that factors such as ecological opportunity may play a more important role than host plant chemistry in explaining the lack of natural associations with some hosts.

  12. Host preferences of blood-feeding mosquitoes

    NARCIS (Netherlands)

    Takken, W.; Verhulst, N.O.


    Mosquitoes use plant sugars and vertebrate blood as nutritional resources. When searching for blood hosts, some mosquitoes express preferential behavior for selected species. Here, we review the available knowledge on host preference, as this is expected to affect the life history and transmission

  13. Host allometry influences the evolution of parasite host-generalism: theory and meta-analysis (United States)

    Hurford, Amy; Ellison, Amy R.


    Parasites vary widely in the diversity of hosts they infect: some parasite species are specialists—infecting just a single host species, while others are generalists, capable of infecting many. Understanding the factors that drive parasite host-generalism is of basic biological interest, but also directly relevant to predicting disease emergence in new host species, identifying parasites that are likely to have unidentified additional hosts, and assessing transmission risk. Here, we use mathematical models to investigate how variation in host body size and environmental temperature affect the evolution of parasite host-generalism. We predict that parasites are more likely to evolve a generalist strategy when hosts are large-bodied, when variation in host body size is large, and in cooler environments. We then explore these predictions using a newly updated database of over 20 000 fish–macroparasite associations. Within the database we see some evidence supporting these predictions, but also highlight mismatches between theory and data. By combining these two approaches, we establish a theoretical basis for interpreting empirical data on parasites' host specificity and identify key areas for future work that will help untangle the drivers of parasite host-generalism. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’. PMID:28289257

  14. Mosquito host selection varies seasonally with host availability and mosquito density.

    Directory of Open Access Journals (Sweden)

    Tara C Thiemann


    Full Text Available Host selection by vector mosquitoes is a critical component of virus proliferation, particularly for viruses such as West Nile (WNV that are transmitted enzootically to a variety of avian hosts, and tangentially to dead-end hosts such as humans. Culex tarsalis is a principal vector of WNV in rural areas of western North America. Based on previous work, Cx. tarsalis utilizes a variety of avian and mammalian hosts and tends to feed more frequently on mammals in the late summer than during the rest of the year. To further explore this and other temporal changes in host selection, bloodfed females were collected at a rural farmstead and heron nesting site in Northern California from May 2008 through May 2009, and bloodmeal hosts identified using either a microsphere-based array or by sequencing of the mitochondrial cytochrome c oxidase I (COI gene. Host composition during summer was dominated by four species of nesting Ardeidae. In addition, the site was populated with various passerine species as well as domestic farm animals and humans. When present, Cx. tarsalis fed predominantly (>80% upon the ardeids, with Black-crowned Night-Herons, a highly competent WNV host, the most prevalent summer host. As the ardeids fledged and left the area and mosquito abundance increased in late summer, Cx. tarsalis feeding shifted to include more mammals, primarily cattle, and a high diversity of avian species. In the winter, Yellow-billed Magpies and House Sparrows were the predominant hosts, and Yellow-billed Magpies and American Robins were fed upon more frequently than expected given their relative abundance. These data demonstrated that host selection was likely based both on host availability and differences in utilization, that the shift of bloodfeeding to include more mammalian hosts was likely the result of both host availability and increased mosquito abundance, and that WNV-competent hosts were fed upon by Cx. tarsalis throughout the year.

  15. Host range expansion is density dependent. (United States)

    Castagneyrol, Bastien; Jactel, Hervé; Brockerhoff, Eckehard G; Perrette, Nicolas; Larter, Maximilien; Delzon, Sylvain; Piou, Dominique


    The realized host range of herbivores is expected to increase with herbivore population density. Theory also predicts that trait similarity and phylogenetic relatedness between native and exotic plants is expected to increase the susceptibility of introduced plants to feeding by native herbivores. Whether the ability of native herbivores to extend their host range to introduced species is density dependent is still unknown. We addressed this question by monitoring pine processionary moth (PPM, Thaumetopoea pityocampa) attacks during nine consecutive years on 41 pine species (8 native and 33 introduced) planted in an arboretum. The survey encompassed latent and outbreak periods. A total of 28 pine species were attacked by PPM. There was no difference in the probability of attack between native and introduced pine species. Host range increased and was more phylogenetically clustered during outbreak than latent periods. When population density increased, PPM expanded its diet breadth by attacking introduced pine species that were closely related to native hosts. This study demonstrates the density dependence of host range expansion in a common pine herbivore. Importantly, it supports the idea that the degree of phylogenetic proximity between host species can be a better predictor of attacks than the introduction status, which may help to predict the outcomes of new plant-herbivore interactions.

  16. Chemical similarity between historical and novel host plants promotes range and host expansion of the mountain pine beetle in a naïve host ecosystem. (United States)

    Erbilgin, Nadir; Ma, Cary; Whitehouse, Caroline; Shan, Bin; Najar, Ahmed; Evenden, Maya


    Host plant secondary chemistry can have cascading impacts on host and range expansion of herbivorous insect populations. We investigated the role of host secondary compounds on pheromone production by the mountain pine beetle (Dendroctonus ponderosae) (MPB) and beetle attraction in response to a historical (lodgepole pine, Pinus contorta var. latifolia) and a novel (jack pine, Pinus banksiana) hosts, as pheromones regulate the host colonization process. Beetles emit the same pheromones from both hosts, but more trans-verbenol, the primary aggregation pheromone, was emitted by female beetles on the novel host. The phloem of the novel host contains more α-pinene, a secondary compound that is the precursor for trans-verbenol production in beetle, than the historical host. Beetle-induced emission of 3-carene, another secondary compound found in both hosts, was also higher from the novel host. Field tests showed that the addition of 3-carene to the pheromone mixture mimicking the aggregation pheromones produced from the two host species increased beetle capture. We conclude that chemical similarity between historical and novel hosts has facilitated host expansion of MPB in jack pine forests through the exploitation of common host secondary compounds for pheromone production and aggregation on the hosts. Furthermore, broods emerging from the novel host were larger in terms of body size.

  17. The genetics of non-host resistance to the lettuce pathogen Bremia lactucae in Lactuca saligna

    NARCIS (Netherlands)

    Jeuken, M.J.W.


    Plants are continuously exposed to a wide variety of pathogens. However, all plant species are non-hosts for the majority of the potential plant pathogens. The genetic dissection of non-host resistance is hampered by the lack of segregating population from crosses between host and non-host species,

  18. A New Species of the Genus Nanhaipotamon (Decapoda : Potamidae)Serving as Intermediate Host of Paragonimus skrjabini%斯氏并殖吸虫宿主南海溪蟹属一新种记述(十足目:溪蟹科)

    Institute of Scientific and Technical Information of China (English)

    林国华; 程由注; 陈韶红


    and Zhenghe Counties. Conclusion A new species of freshwater crab (Nanhaipotamon fujianense sp. nov.) has been recorded which serves as the intermediate hosts of Paragonimus skrjabini.

  19. 盆栽榕树蓟马种类及优势种榕管蓟马对寄主植物的致害性%Species of thrips on potted ficus and the degree of damage to different host plants by the dominant species Gynaikothrips uzeli (Thysanoptera:Thripidae)

    Institute of Scientific and Technical Information of China (English)

    余德亿; 黄鹏; 姚锦爱; 王联德; 王金明


    To investigate the thrips species on potted ficus and to understand the damage difference by dominant thrips to Ficus and non-Ficus potted plants mixing planted in the same greenhouse, we collected the leaves of potted Ficus plants from the Ficus Planting-Demonstration Base of Zhangzhou, Fuzhou and Quanzhou, surveyed the thrips species and determined the dominant species, and the damage degree by Gynaikothrips uzeli Zimmerman on different host plants including Araceae Philodenron, Bignoniaceae Radermachera, Bombacaceae Pachira and Moraceae Ficus potted plants was also investigated. The results showed that there were 9 thrips species belonging to eight genera of two families in two suborders on potted ficus, of which G. uzeli was the dominant species, Androthrips ramachandrai Kamy and Mesothrips jordani Zimmermann were the common species, and the other six thrips species were the occasional species. A narrow host range of G. uzeli was found. G. uzeli had the most serious damage to Moraceae Ficus, but had the weaker damage to Philodendron, Radermachera, and Pachira plants. Of the six Ficus species, the damage degrees of G. uzeli reached higher than level three to Ficus benjamina Linn., F. microcarpa Linn. F. and F. benjamina cv. Golden Princess, of which G. uzeli caused the highest damage to the F. benjamina Linn., the second highest damage to F. microcarpa Linn. F. and the milder damage to F. benjamina cv. Golden Princess. The damages of the pest were only level one to F. microcarpa cv.Golden Leaves, F. elastica cv. Deocora Burgundy and F. elastica var. variegata. G. uzeli had higher fecundity on F. microcarpa Linn. F. F. benjamina Linn, and F. benjamina cv. Golden Princess, and could complete one generation on them, but had the best developmental performance on F. benjamina Linn. G. uzeli had lower fecundity on F. microcarpa cv. Golden Leaves, F. elastica cv. Deocora Burgundy and F. elastica var. variegata, and could not complete one generation on them. These

  20. Community composition and species richness of parasitoids infesting Yponomeuta species in the Netherlands

    NARCIS (Netherlands)

    Cleary, Daniel F.R.


    Parasitoid assemblages infesting Yponomeuta species in the Netherlands were investigated. Parasitoid species richness and community composition were related to host species, habitat, temporal and spatial variation. Both community structure and species richness did not differ among habitats. There

  1. Animal salmonelloses: a brief review of “host adaptation and host specificity” of Salmonella spp.

    Directory of Open Access Journals (Sweden)

    Grammato Evangelopoulou


    Full Text Available Salmonella enterica, the most pathogenic species of the genusSalmonella, includes more than 2,500 serovars, many of which are of great veterinary and medical significance. The emergence of food-borne pathogens, such as Salmonella spp., has increased knowledge about the mechanisms helping microorganisms to persist and spread within new host populations. It has also increased information about the properties they acquire for adapting in the biological environment of a new host. Thedifferences observed between serovars in their host preference and clinical manifestations are referred to as “serovar-host specificity” or “serovar-host adaptation”. The genus Salmonella, highly adaptive to vertebrate hosts, has many pathogenic serovars showing host specificity. Serovar Salmonella Typhi, causing disease to man and higher primates, is a good example of host specificity. Thus, understanding the mechanisms that Salmonella serovars use to overcome animal species' barriers or adapt to new hosts is also important for understanding the origins of any other infectious diseases or the emergence of new pathogens. In addition, molecular methods used to study the virulence determinants of Salmonella serovars, could also be used to model ways of studying the virulence determinants used by bacteria in general, when causing disease to a specific animal species

  2. Oviposition choice of two fall armyworm (Lepidoptera: Noctuidae) host strains (United States)

    Fall armyworm, Spodoptera frugiperda (J. E. Smith), is a noctuid species that is composed of two morphologically identical sympatric host strains (corn and rice) that differ in their distribution among plant hosts. In an effort to explain observations of host fidelity in the field, ovipositional pre...

  3. Temperature alters host genotype-specific susceptibility to chytrid infection

    NARCIS (Netherlands)

    Gsell, A.S.; De Senerpont Domis, L.N.; Van Donk, E.; Ibelings, B.W.


    The cost of parasitism often depends on environmental conditions and host identity. Therefore, variation in the biotic and abiotic environment can have repercussions on both, species-level host-parasite interaction patterns but also on host genotype-specific susceptibility to disease. We exposed sev

  4. What determines host acceptance and suitability in tropical Asian Drosophila parasitoids? (United States)

    Kimura, Masahito T; Suwito, Awit


    For successful parasitism, parasitoid females must oviposit and the progeny must develop in individual hosts. Here, we investigated the determinants of host acceptance for oviposition and host suitability for larval development of Drosophila parasitoids from Bogor and Kota Kinabalu (≍1,800 km northeast of Bogor), Indonesia, in tropical Asia. Asobara pleuralis (Ashmead) from both localities oviposited frequently (>60%) in all of the drosophilid species tested, except the strain from Kota Kinabalu oviposited rarely (10%) in Drosophila eugracilis Bock & Wheeler. Leptopilina victoriae Nordlander from both localities only oviposited frequently (>77%) in species from the Drosophila melanogaster species group except D. eugracilis (85%) only in species from the Drosophila immigrans species group. Thus, host acceptance appeared to be affected by host taxonomy, at least in Leptopilina species. Host suitability varied considerably, even among closely related drosophilid species, which suggests that the host suitability is at least in part independent of host taxonomy and that it has been determined via parasitoid-host coevolutionary interactions (i.e., arms race). Host acceptance did not always coincide with host suitability, i.e., parasitoids sometimes oviposited in unsuitable host species. Geographic origin strongly affected the host acceptance and suitability in the A. pleuralis-D. eugracilis parasitoid-host pair, whereas it only weakly affected the acceptability and suitability in other parasitoid-host combinations.

  5. Inter- and intra-specific host discrimination in gregarious and solitary endoparasitoid wasps

    NARCIS (Netherlands)

    Magdaraog, P.M.; Tanaka, T.; Harvey, J.A.


    In nature, most species of Lepidoptera are attacked by parasitoids, and some species may be hosts for several parasitoid species. When hosts are parasitized by more than one female of the same species (=superparasitism) or females of different species (=multiparasitism), then intrinsic competition o


    Institute of Scientific and Technical Information of China (English)

    米晓云; 古努尔·吐尔逊; 张壮志; 石保新; 吐尔洪·依米提; 张旭; 赵莉; 金映红; 张文宝


    To establish an animal infection model, four of each of the following rodent species were infected with Echinococcus multilocularis protoscolexes: Djungarian Hamsters (Dwarf Campbells Russian Hamster ) , dwarf winter white Russian hamsters (Phodopus sungozis sungoris), Mesocricetus auratuses and Sciurus vulgarises. At 70 days post infection, one animal from each species was sacrificed and examined for the presence of cysts. The cysts were not found in Djungarian hamster, Mesocricetus auratus and Sciurus vulgaris. However, 4.37g cysts that accounted for 7.23% of body weight were found in a dwarf winter white Russian hamster at 70 days post infection. At 95 days post infection, the cysts were not found in Djungarian hamsters. The mean wet cyst weight and cyst/body weight percentage were 13.05 g and 33.03%, 2.22 g and 1.98%, and 2.28 g and 3.54% in Phodopus sungoris sungoris Syrian hamsters, Mesocricetus auratuses, and Sciurus vulgarizes, respectively. In addition, mature protoscolexes were found in all animals except Djungarian hamsters. These results suggested that Phodopus sungoris sungods, Mesocricetus auratuses and Sciurus vulgarizes were susceptible to protoscolex infection of Echinococcus multilocularis and might serve as the intermediate host of Echinococcus multilocularis.%用多房棘球绦虫(Echinococcus multilocularis,Em)原头蚴继发感染一线仓鼠(坎培尔仓鼠Dwarf Campbells Russian Hamster)、冬白仓鼠(倭仓鼠Phodopus sungoris sungoris)、金丝熊仓鼠(黄金鼠Mesocricetus auratus)、松鼠(Sciurusvulgaris)4种宠物鼠各4只。接种70d后剖解各种宠物鼠1只,一线仓鼠、金丝熊仓鼠、松鼠未发现包囊泡,冬白仓鼠分离出包囊泡4.37g,占体重的7.23%;接种95d后4种宠物鼠的平均湿包囊泡重和包囊泡重占体重的百分比分别为:冬白仓鼠13.05g和33.03%,金丝熊仓鼠2-22g和1.98%,松鼠2.28g和3.54%,冬白仓鼠、金丝

  7. Hebeloma species associated with Cistus

    NARCIS (Netherlands)

    Eberhardt, U.; Beker, H.J.; Vila, J.; Vesterholt, J.; Llimona, X.; Gadjieva, R.


    The genus Hebeloma has a number of species highly specific to Cistus and others that occur with several host genera. This paper discusses the species of Hebeloma that appear to be ectomycorrhizal with Cistus, judging from their occurrence when Cistus is the only available host. The previously

  8. Genetic variation changes the interactions between the parasitic plant-ecosystem engineer Rhinanthus and its hosts. (United States)

    Rowntree, Jennifer K; Cameron, Duncan D; Preziosi, Richard F


    Within-species genetic variation is a potent factor influencing between-species interactions and community-level structure. Species of the hemi-parasitic plant genus Rhinanthus act as ecosystem engineers, significantly altering above- and below-ground community structure in grasslands. Here, we show the importance of genotypic variation within a single host species (barley-Hordeum vulgare), and population-level variation among two species of parasite (Rhinanthus minor and Rhinanthus angustifolius) on the outcome of parasite infection for both partners. We measured host fitness (number of seeds) and calculated parasite virulence as the difference in seed set between infected and uninfected hosts (the inverse of host tolerance). Virulence was determined by genetic variation within the host species and among the parasite species, but R. angustifolius was consistently more virulent than R. minor. The most tolerant host had the lowest inherent fitness and did not gain a fitness advantage over other infected hosts. We measured parasite size as a proxy for transmission ability (ability to infect further hosts) and host resistance. Parasite size depended on the specific combination of host genotype, parasite species and parasite population, and no species was consistently larger. We demonstrate that the outcome of infection by Rhinanthus depends not only on the host species, but also on the underlying genetics of both host and parasite. Thus, genetic variations within host and parasite are probably essential components of the ecosystem-altering effects of Rhinanthus.

  9. Host preference of the bean weevil Zabrotes subfasciatus

    Institute of Scientific and Technical Information of China (English)

    Isabel Ribeiro do Valle Teixeira; Angel Roberto Barchuk; Fernando Sérgio Zucoloto


    It is largely known that the range of an insect diet is mostly determined by oviposition behavior, mainly in species with endophytic larvae such as Zabrotes subfasciatus.However, the proximate factors determining host choice and the subsequent steps leading to the expansion or reduction of the host number and occasional host shifts are largelyun known. We analyzed various factors determining host preference of Z. subfasciatus through the evaluation of: (i) oviposition preference of a wild population of Z. subfasciatus on the usual host (bean) and unusual hosts (lentil, chickpea and soy), and the performance of the offspring; (ii) artificial selection for increasing preference for hosts initially less frequently chosen; (iii) comparison of oviposition behavior between two different popula-tions (reared for~30 generations in beans or chickpeas, respectively); (iv) oviposition timing on usual and unusual hosts; and (v) identification of preference hierarchies. We found that when using unusual hosts, there is no correlation between performance and preference and that the preference hierarchy changes only slightly when the population passes through several generations on the less frequently accepted host. We also found a positive response to artificial selection for increasing oviposition on the less preferred host; however, when the host-choice experiment involved two varieties of the usual host, the response was faster than when the choice involved usual and unusual hosts. Finally, beetles reared on an unusual host (chickpea) for 26 generations showed similar good fitness on both usual and unusual hosts,indicating that the use of a new host does not necessarily result in the loss of performance on the original host. Nevertheless, this population showed lower fitness on the usual host than that of the original population, suggesting an underlying partial trade-off phenomenon which may contribute to a broadening of diet of this insect species.

  10. Patterns of gregarine parasitism in dragonflies: host, habitat, and seasonality. (United States)

    Locklin, Jason L; Vodopich, Darrell S


    Gregarines are ubiquitous protozoan parasites that infect arthropods worldwide. More than 1,600 gregarine species have been described, but only a small percentage of invertebrates have been surveyed for these apicomplexan parasites. Adult dragonfly populations were surveyed for gregarines at two reservoirs in Texas, USA for 2 years. Gregarine prevalence and intensity were compared intraspecifically between host genders and reservoirs, among wing loads, and through time. Of the 29 dragonfly species collected, 41% hosted gregarines. Nine of these dragonfly species were previously undocumented as hosts. Among the commonly collected hosts, prevalence ranged from 18 to 52%. Parasites were aggregated among hosts and had a median intensity of five parasites per host. Gregarines were found only in hosts exceeding a minimum wing load, indicating that gregarines are likely not transferred from the naiad to adult during emergence. Prevalence and intensity increased during both years, suggesting that gregarine oocyst viability parallels increasing host population densities and may be short-lived. Prevalence and intensity also differed between dragonfly populations at two reservoirs. Regression analyses revealed that host species, host gender, month, and year were significant explanatory variables related to gregarine prevalence and intensity. Abundant information on odonate distributions, diversity, and mating activities makes dragonfly-gregarine systems excellent avenues for ecological, evolutionary, and parasitological research. Our results emphasize the importance of considering season, hosts, and habitat when studying gregarine-dragonfly ecology.

  11. Genetic differentiation among sympatric cuckoo host races: males matter. (United States)

    Fossøy, Frode; Antonov, Anton; Moksnes, Arne; Røskaft, Eivin; Vikan, Johan R; Møller, Anders P; Shykoff, Jacqui A; Stokke, Bård G


    Generalist parasites regularly evolve host-specific races that each specialize on one particular host species. Many host-specific races originate from geographically structured populations where local adaptations to different host species drive the differentiation of distinct races. However, in sympatric populations where several host races coexist, gene flow could potentially disrupt such host-specific adaptations. Here, we analyse genetic differentiation among three sympatrically breeding host races of the brood-parasitic common cuckoo, Cuculus canorus. In this species, host-specific adaptations are assumed to be controlled by females only, possibly via the female-specific W-chromosome, thereby avoiding that gene flow via males disrupts local adaptations. Although males were more likely to have offspring in two different host species (43% versus 7%), they did not have significantly more descendants being raised outside their putative foster species than females (9% versus 2%). We found significant genetic differentiation for both biparentally inherited microsatellite DNA markers and maternally inherited mitochondrial DNA markers. To our knowledge, this is the first study that finds significant genetic differentiation in biparentally inherited markers among cuckoo host-specific races. Our results imply that males also may contribute to the evolution and maintenance of the different races, and hence that the genes responsible for egg phenotype may be found on autosomal chromosomes rather than the female-specific W-chromosome as previously assumed.

  12. The causes and consequences of changes in virulence following pathogen host shifts. (United States)

    Longdon, Ben; Hadfield, Jarrod D; Day, Jonathan P; Smith, Sophia C L; McGonigle, John E; Cogni, Rodrigo; Cao, Chuan; Jiggins, Francis M


    Emerging infectious diseases are often the result of a host shift, where the pathogen originates from a different host species. Virulence--the harm a pathogen does to its host-can be extremely high following a host shift (for example Ebola, HIV, and SARs), while other host shifts may go undetected as they cause few symptoms in the new host. Here we examine how virulence varies across host species by carrying out a large cross infection experiment using 48 species of Drosophilidae and an RNA virus. Host shifts resulted in dramatic variation in virulence, with benign infections in some species and rapid death in others. The change in virulence was highly predictable from the host phylogeny, with hosts clustering together in distinct clades displaying high or low virulence. High levels of virulence are associated with high viral loads, and this may determine the transmission rate of the virus.

  13. Host range of meliolaceous fungi in India

    Directory of Open Access Journals (Sweden)

    V.B. Hosagoudar


    Full Text Available The order Meliolales comprises two families, namely, Armatellaceae and Meliolaceae. Except the genera Endomeliola and Pauhia, India represents rest of the nine genera of this group. The family Armatellaceae includes two genera, namely, Armatella and Basavamyces. The family Meliolaceae includes seven genera: Amazonia, Appendiculella, Asteridiella, Ectendomeliola, Irenopsis, Meliola and Prataprajella. All these nine genera represent 613 species and infra-specific taxa known till the year 2006, infected 766 host plants belonging to 349 host genera distributed among 104 families. All the host families and the fungal genera are arranged alphabetically with their corresponding parasite and the host plant. The corresponding number after the host family represents the number of meliolaceous taxa known on the members of that family.

  14. Treponema denticola interactions with host proteins

    Directory of Open Access Journals (Sweden)

    J. Christopher Fenno


    Full Text Available Oral Treponema species, most notably T. denticola, are implicated in the destructive effects of human periodontal disease. Progress in the molecular analysis of interactions between T. denticola and host proteins is reviewed here, with particular emphasis on the characterization of surface-expressed and secreted proteins of T. denticola involved in interactions with host cells, extracellular matrix components, and components of the innate immune system.

  15. Natal Host Plants Can Alter Herbivore Competition


    Pan, Huipeng; Evan L. Preisser; Su, Qi; Jiao, Xiaoguo; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Zhang, Youjun


    Interspecific competition between herbivores is widely recognized as an important determinant of community structure. Although researchers have identified a number of factors capable of altering competitive interactions, few studies have addressed the influence of neighboring plant species. If adaptation to/ epigenetic effects of an herbivore’s natal host plant alter its performance on other host plants, then interspecific herbivore interactions may play out differently in heterogeneous and h...

  16. Host Specificity in the Parasitic Plant Cytinus hypocistis

    Directory of Open Access Journals (Sweden)

    C. J. Thorogood


    Full Text Available Host specificity in the parasitic plant Cytinus hypocistis was quantified at four sites in the Algarve region of Portugal from 2002 to 2007. The parasite was found to be locally host specific, and only two hosts were consistently infected: Halimium halimifolium and Cistus monspeliensis. C. hypocistis did not infect hosts in proportion to their abundance; at three sites, 100% of parasites occurred on H. halimifolium which represented just 42.4%, 3% and 19.7% of potential hosts available, respectively. At the remaining site, where H. halimifolium was absent, 100% of parasites occurred on C. monspeliensis which represented 81.1% of potential hosts available. Other species of potential host were consistently uninfected irrespective of their abundance. Ecological niche divergence of host plants H. halimifolium and C. monspeliensis may isolate host-specific races of C. hypocistis, thereby potentially driving allopatric divergence in this parasitic plant.

  17. Molecular phylogenies reveal host-specific divergence of Ophiocordyceps unilateralis sensu lato following its host ants. (United States)

    Kobmoo, N; Mongkolsamrit, S; Tasanathai, K; Thanakitpipattana, D; Luangsa-Ard, J J


    Ophiocordyceps unilateralis (Hypocreales, Ascomycetes) is an entomopathogenic fungus specific to formicine ants (Formicinae, Hymenoptera). Previous works have shown that the carpenter ant Camponotus leonardi acts as the principal host with occasional infections of ants from the genus Polyrhachis (sister genus of Camponotus). Observations were made on the permanent plots of Mo Singto, Khao Yai National Park of Thailand according to which O. unilateralis was found to occur predominantly on three host species: C. leonardi, C. saundersi and P. furcata. Molecular phylogenies of the elongation factor 1-α and β-Tubulin genes indicate a separation of O. unilateralis samples into three clades, reflecting specificity to each of the three different ant species. Samples collected from P. furcata and from C. leonardi were found to form sister groups with samples from C. saundersi forming an outgroup to the latter. Additional samples collected from unidentified ant species of Camponotus and Polyrhachis were positioned as outgroups to those samples on identified species. These results demonstrate that O. unilateralis is clearly not a single phylogenetic species and comprises at least three species that are specific to different host ant species. These cryptic species may arise through recent events of speciation driven by their specificity to host ant species.

  18. A parasite's modification of host behavior reduces predation on its host. (United States)

    Soghigian, John; Valsdottir, Linda R; Livdahl, Todd P


    Parasite modification of host behavior is common, and the literature is dominated by demonstrations of enhanced predation on parasitized prey resulting in transmission of parasites to their next host. We present a case in which predation on parasitized prey is reduced. Despite theoretical modeling suggesting that this phenomenon should be common, it has been reported in only a few host-parasite-predator systems. Using a system of gregarine endosymbionts in host mosquitoes, we designed experiments to compare the vulnerability of parasitized and unparasitized mosquito larvae to predation by obligate predatory mosquito larvae and then compared behavioral features known to change in the presence of predatory cues. We exposed Aedes triseriatus larvae to the parasite Ascogregarina barretti and the predator Toxohrynchites rutilus and assessed larval mortality rate under each treatment condition. Further, we assessed behavioral differences in larvae due to infection and predation stimuli by recording larvae and scoring behaviors and positions within microcosms. Infection with gregarines reduced cohort mortality in the presence of the predator, but the parasite did not affect mortality alone. Further, infection by parasites altered behavior such that infected hosts thrashed less frequently than uninfected hosts and were found more frequently on or in a refuge within the microcosm. By reducing predation on their host, gregarines may be acting as mutualists in the presence of predation on their hosts. These results illustrate a higher-order interaction, in which a relationship between a species pair (host-endosymbiont or predator-prey) is altered by the presence of a third species.

  19. Treatment of candidiasis: insights from host genetics. (United States)

    Delsing, Corine E; Bleeker-Rovers, Chantal P; Kullberg, Bart-Jan; Netea, Mihai G


    Candida species are major causes of mucosal and invasive infections, leading to substantial morbidity and mortality. Despite the development of new classes of antifungal drugs, mortality in patients with systemic candidiasis remains high. Host-Candida interaction plays an important role in effective elimination of the pathogen. Genetic studies have rendered important insights into antifungal host defense and have identified potential targets for adjunctive therapy. In this article, the authors review the genetic variations in the host defense to Candida and their implications for the treatment of mucosal and systemic candidiasis.

  20. Investigation of the midgut structure and ultrastructure in Cimex lectularius and Cimex pipistrelli (Hemiptera: Cimicidae)


    Rost-Roszkowska, M. M.; Vilimova, J; Włodarczyk, A; Sonakowska, L; Kamińska, K; Kaszuba, F; Marchewka, A; Sadílek, D


    Cimicidae are temporary ectoparasites, which means that they cannot obtain food continuously. Both Cimex species examined here, Cimex lectularius (Linnaeus 1758) and Cimex pipistrelli (Jenyns 1839), can feed on a non-natal host, C. lectularius from humans on bats, C. pipistrelli on humans, but never naturally. The midgut of C. lectularius and C. pipistrelli is composed of three distinct regions—the anterior midgut (AMG), which has a sack-like shape, the long tube-shaped middle midgut (MMG), a...

  1. [A new parasitological index for the estimation of peculiarities of the relationships between parasite and its host, and biotope of the host]. (United States)

    Bogdanov, I I; Chachina, S B; Korallo, N P; Dmitriev, V V


    A new parasitological index (hostal-topical index) for the estimation of the degree of ectoparasite's relationship with its host and biotope of the host is proposed: [formula: see text], where [formula: see text]--hostal-topical index; n--amount of ectoparasites of the given species on the given host species in the biotope; N--amount of ectoparasites of all species from the given taxonomic group on the given host species in the biotope; n1--amount of hosts of the given species in the biotope; N1--amount of hosts of all species from the given taxonomic group in the biotope; n2--amount of ectoparasites of the given species in the biotope; N2--amount of ectoparasites of all species from the given taxonomic group in the biotope. Values [formula: see text] 0.5 indicate a significant relationship with the host. By means of this index we have analyzed peculiarity of several parasitic species of fleas and gamasid mites to their hosts, biotopes, and biotope through the host. As it was found on the materials from different native zones and subzones of the Omsk Region (Western Siberia, Russia), values of the hostal-topical index for polyhostal parasitic species are lesser than those for oligohostal species. Values of this index can be different for the same species in the different native zones and subzones as well as in the different biotopes of the same native zone (subzone).

  2. Nestedness of ectoparasite-vertebrate host networks.

    Directory of Open Access Journals (Sweden)

    Sean P Graham

    Full Text Available Determining the structure of ectoparasite-host networks will enable disease ecologists to better understand and predict the spread of vector-borne diseases. If these networks have consistent properties, then studying the structure of well-understood networks could lead to extrapolation of these properties to others, including those that support emerging pathogens. Borrowing a quantitative measure of network structure from studies of mutualistic relationships between plants and their pollinators, we analyzed 29 ectoparasite-vertebrate host networks--including three derived from molecular bloodmeal analysis of mosquito feeding patterns--using measures of nestedness to identify non-random interactions among species. We found significant nestedness in ectoparasite-vertebrate host lists for habitats ranging from tropical rainforests to polar environments. These networks showed non-random patterns of nesting, and did not differ significantly from published estimates of nestedness from mutualistic networks. Mutualistic and antagonistic networks appear to be organized similarly, with generalized ectoparasites interacting with hosts that attract many ectoparasites and more specialized ectoparasites usually interacting with these same "generalized" hosts. This finding has implications for understanding the network dynamics of vector-born pathogens. We suggest that nestedness (rather than random ectoparasite-host associations can allow rapid transfer of pathogens throughout a network, and expand upon such concepts as the dilution effect, bridge vectors, and host switching in the context of nested ectoparasite-vertebrate host networks.

  3. Host-pathogen interactions during apoptosis

    Indian Academy of Sciences (India)

    Seyed E Hasnain; Rasheeda Begum; K V A Ramaiah; Sudhir Sahdev; E M Shajil; Tarvinder K Taneja; Manjari Mohan; M Athar; Nand K Sah; M Krishnaveni


    Host pathogen interaction results in a variety of responses, which include phagocytosis of the pathogen, release of cytokines, secretion of toxins, as well as production of reactive oxygen species (ROS). Recent studies have shown that many pathogens exert control on the processes that regulate apoptosis in the host. The induction of apoptosis upon infection results from a complex interaction of parasite proteins with cellular host proteins. Abrogation of host cell apoptosis is often beneficial for the pathogen and results in a successful host invasion. However, in some cases, it has been shown that induction of apoptosis in the infected cells significantly imparts protection to the host from the pathogen. There is a strong correlation between apoptosis and the host protein translation machinery: the pathogen makes all possible efforts to modify this process so as to inhibit cell suicide and ensure that it can survive and, in some cases, establish latent infection. This review discusses the significance of various pathways/steps during virus-mediated modulation of host cell apoptosis.

  4. Climate change, phenology, and butterfly host plant utilization. (United States)

    Navarro-Cano, Jose A; Karlsson, Bengt; Posledovich, Diana; Toftegaard, Tenna; Wiklund, Christer; Ehrlén, Johan; Gotthard, Karl


    Knowledge of how species interactions are influenced by climate warming is paramount to understand current biodiversity changes. We review phenological changes of Swedish butterflies during the latest decades and explore potential climate effects on butterfly-host plant interactions using the Orange tip butterfly Anthocharis cardamines and its host plants as a model system. This butterfly has advanced its appearance dates substantially, and its mean flight date shows a positive correlation with latitude. We show that there is a large latitudinal variation in host use and that butterfly populations select plant individuals based on their flowering phenology. We conclude that A. cardamines is a phenological specialist but a host species generalist. This implies that thermal plasticity for spring development influences host utilization of the butterfly through effects on the phenological matching with its host plants. However, the host utilization strategy of A. cardamines appears to render it resilient to relatively large variation in climate.

  5. Baculovirus Host-Range

    Institute of Scientific and Technical Information of China (English)

    Suzanne M. Thiem; Xiao-Wen Cheng


    Baculoviruses are used as microbial insecticides, protein expression vectors, epitope display platforms, and most recently as vectors for gene therapy. Understanding the mechanisms that control baculovirus host-range and tissue tropisms are important for assessing their safety and for improving their properties for these biotechnology applications. In the past two decades some progress has been made and several baculovirus genes that influence host-range have been identified. Despite this progress, our understanding of the underlying mechanisms that restrict baculovirus host-range is still limited. Here we review what is currently known about baculovirus genes that influence virus host-range.

  6. Investigation on the Hosts with Natural Paragonimus Infection and Species Identification in Jinhua Prefecture of Zhejiang Province%浙江省金华地区并殖吸虫自然宿主调查及虫种鉴定

    Institute of Scientific and Technical Information of China (English)

    楼宏强; 胡野; 金耀建; 余新图; 王岚; 何旭英; 屠平光


    Objective To investigate the natural hosts infected with Paragonimus sp. And identify the species of the parasite in selected counties/districts of Jinhua prefecture in Zhejiang Province. Methods Three townships/towns were randomly sampled from each of the 9 counties/districts in Jinhua as pilot spots for the survey. Fresh-water snails were collected from the fields for examining cercariae. Crabs were collected and detected for metacercariae by routine technique and the metacercariae were fed to dogs purchased in areas free from paragonimiasis. Fecal materials of dogs and cats around the villages and streams where crabs were found infected were collected for examining eggs. The artificially infected dogs were sacrificed 55 d after infection to receive adult worms. The size of cercariae, metacercariae, eggs and adult worms was measured. After the DNA of the adult worm was extracted, PCR was used to amplify the COI gene and ITS2 gene of the mitochondria from the worms. Homology with relative strains/isolates was analyzed and phylo-genetic tree constructed. Results The survey demonstrated that the snail Semisulcospira libertina and the crab Sinopotamon chekiangense served as the first and second intermediate hosts respectively. Natural infection was found in Wucheng District with an infection rate of 0.2% (2/1 088) in snails and 76.7% (46/60) in crabs in Shafan township, and an infection index (II) of 2.0 in crabs, 0.1% (1/1 683) in snails and 53.0% (46/60) in crabs with an II of 0.9 inLangya town. The infection rate was 0 (0/575) in snails and 30.0% (18/60) in crabs with an II of 0.1 in Baimu township of Wuyi County. Paragonimus eggs were detected in feces of stray cats with a positive rate of 8.3% (1/12) in Shafan and 0.6% (1/17) in Langya. The size and morphology of the cercariae, metacercariae, eggs and adult worms were similar to those of Paragonimus westermani. The sequences of the COI and ITS2 genes were with 390 bp and 363 bp respectively, indicating a

  7. Host susceptibility of the papaya mosaic virus in Sri Lanka. (United States)

    Rajapakse, R H; Herath, H M


    75 plant species from 11 families were tested in Sri Lanka for their susceptibility to transferring the papaya mosaic virus. After inoculation with this virus, six species, Cucurbita pepo, Cucumis sativus, Nicotiana tabacum, Chenopodium amaranticolor, Gomphrena globosa and Lycopersicum esculentum, developed such symptoms, and after re-isolation from the host plant the virus again infected papaya plants. Thus these species are possible alternate hosts of papaya mosaic virus in Sri Lanka.

  8. Host shift and speciation in a coral-feeding nudibranch (United States)

    Faucci, Anuschka; Toonen, Robert J; Hadfield, Michael G


    While the role of host preference in ecological speciation has been investigated extensively in terrestrial systems, very little is known in marine environments. Host preference combined with mate choice on the preferred host can lead to population subdivision and adaptation leading to host shifts. We use a phylogenetic approach based on two mitochondrial genetic markers to disentangle the taxonomic status and to investigate the role of host specificity in the speciation of the nudibranch genus Phestilla (Gastropoda, Opisthobranchia) from Guam, Palau and Hawaii. Species of the genus Phestilla complete their life cycle almost entirely on their specific host coral (species of Porites, Goniopora and Tubastrea). They reproduce on their host coral and their planktonic larvae require a host-specific chemical cue to metamorphose and settle onto their host. The phylogenetic trees of the combined cytochrome oxidase I and ribosomal 16S gene sequences clarify the relationship among species of Phestilla identifying most of the nominal species as monophyletic clades. We found a possible case of host shift from Porites to Goniopora and Tubastrea in sympatric Phestilla spp. This represents one of the first documented cases of host shift as a mechanism underlying speciation in a marine invertebrate. Furthermore, we found highly divergent clades within Phestilla sp. 1 and Phestilla minor (8.1–11.1%), suggesting cryptic speciation. The presence of a strong phylogenetic signal for the coral host confirms that the tight link between species of Phestilla and their host coral probably played an important role in speciation within this genus. PMID:17134995

  9. Natal Host Plants Can Alter Herbivore Competition (United States)

    Pan, Huipeng; Preisser, Evan L.; Su, Qi; Jiao, Xiaoguo; Xie, Wen; Wang, Shaoli; Wu, Qingjun


    Interspecific competition between herbivores is widely recognized as an important determinant of community structure. Although researchers have identified a number of factors capable of altering competitive interactions, few studies have addressed the influence of neighboring plant species. If adaptation to/ epigenetic effects of an herbivore’s natal host plant alter its performance on other host plants, then interspecific herbivore interactions may play out differently in heterogeneous and homogenous plant communities. We tested wether the natal host plant of a whitefly population affected interactions between the Middle-east Asia Minor 1 (MEAM1) and Mediterranean (MED) cryptic species of the whitefly Bemisia tabaci by rearing the offspring of a cabbage-derived MEAM1 population and a poinsettia-derived MED population together on three different host plants: cotton, poinsettia, and cabbage. We found that MED dominated on poinsettia and that MEAM1 dominated on cabbage, results consistent with previous research. MED also dominated when reared with MEAM1 on cotton, however, a result at odds with multiple otherwise-similar studies that reared both species on the same natal plant. Our work provides evidence that natal plants affect competitive interactions on another plant species, and highlights the potential importance of neighboring plant species on herbivore community composition in agricultral systems. PMID:28030636

  10. Natal Host Plants Can Alter Herbivore Competition. (United States)

    Pan, Huipeng; Preisser, Evan L; Su, Qi; Jiao, Xiaoguo; Xie, Wen; Wang, Shaoli; Wu, Qingjun; Zhang, Youjun


    Interspecific competition between herbivores is widely recognized as an important determinant of community structure. Although researchers have identified a number of factors capable of altering competitive interactions, few studies have addressed the influence of neighboring plant species. If adaptation to/ epigenetic effects of an herbivore's natal host plant alter its performance on other host plants, then interspecific herbivore interactions may play out differently in heterogeneous and homogenous plant communities. We tested wether the natal host plant of a whitefly population affected interactions between the Middle-east Asia Minor 1 (MEAM1) and Mediterranean (MED) cryptic species of the whitefly Bemisia tabaci by rearing the offspring of a cabbage-derived MEAM1 population and a poinsettia-derived MED population together on three different host plants: cotton, poinsettia, and cabbage. We found that MED dominated on poinsettia and that MEAM1 dominated on cabbage, results consistent with previous research. MED also dominated when reared with MEAM1 on cotton, however, a result at odds with multiple otherwise-similar studies that reared both species on the same natal plant. Our work provides evidence that natal plants affect competitive interactions on another plant species, and highlights the potential importance of neighboring plant species on herbivore community composition in agricultral systems.

  11. Identification of two lineages of host-associated eriophyoid mites predisposed to different levels of host diversification. (United States)

    Li, Hao-Sen; Hoffmann, Ary A; Guo, Jing-Feng; Zuo, Yun; Xue, Xiao-Feng; Pang, Hong; Hong, Xiao-Yue


    Herbivorous arthropods can diversify as a consequence of evolutionary changes in response to their plant hosts. Current patterns of host association of herbivores are likely to reflect a long evolutionary history of herbivore-plant co-evolution. Here, we used molecular phylogenetics to track the evolutionary history of host shifts and diversification of 66 eriophyoid mites (Acari, Eriophyoidea), and linked past patterns of evolutionary diversification to more recent patterns of divergence by tracking population genetic variation in 13 of the eriophyoid mite species feeding on different gymnosperm hosts. This allowed us to explore the relationship between a past history of diversification and the current potential of mites to undergo host range shifts. We found that population-level diversity across gymnosperm hosts as measured by 28S rRNA markers was greater in species from the mite clade that had radiated across evolutionary time to utilize a variety of hosts including angiosperms, compared to species from the clade that has remained restricted to ancestral gymnosperm hosts. Species from the radiated clade exhibited higher variation in host use. Lineages of mites that have in the past been able to radiate and adapt to diverse plants may therefore be predisposed to continue their expansion on new hosts, although additional clades need to be tested.

  12. Environmentally transmitted parasites: Host-jumping in a heterogeneous environment. (United States)

    Caraco, Thomas; Cizauskas, Carrie A; Wang, Ing-Nang


    Groups of chronically infected reservoir-hosts contaminate resource patches by shedding a parasite׳s free-living stage. Novel-host groups visit the same patches, where they are exposed to infection. We treat arrival at patches, levels of parasite deposition, and infection of the novel host as stochastic processes, and derive the expected time elapsing until a host-jump (initial infection of a novel host) occurs. At stationarity, mean parasite densities are independent of reservoir-host group size. But within-patch parasite-density variances increase with reservoir group size. The probability of infecting a novel host declines with parasite-density variance; consequently larger reservoir groups extend the mean waiting time for host-jumping. Larger novel-host groups increase the probability of a host-jump during any single patch visit, but also reduce the total number of visits per unit time. Interaction of these effects implies that the waiting time for the first infection increases with the novel-host group size. If the reservoir-host uses resource patches in any non-uniform manner, reduced spatial overlap between host species increases the waiting time for host-jumping.

  13. Studies of reservoir hosts for Marburg virus. (United States)

    Swanepoel, Robert; Smit, Sheilagh B; Rollin, Pierre E; Formenty, Pierre; Leman, Patricia A; Kemp, Alan; Burt, Felicity J; Grobbelaar, Antoinette A; Croft, Janice; Bausch, Daniel G; Zeller, Hervé; Leirs, Herwig; Braack, L E O; Libande, Modeste L; Zaki, Sherif; Nichol, Stuart T; Ksiazek, Thomas G; Paweska, Janusz T


    To determine reservoir hosts for Marburg virus (MARV), we examined the fauna of a mine in northeastern Democratic Republic of the Congo. The mine was associated with a protracted outbreak of Marburg hemorrhagic fever during 1998-2000. We found MARV nucleic acid in 12 bats, comprising 3.0%-3.6% of 2 species of insectivorous bat and 1 species of fruit bat. We found antibody to the virus in the serum of 9.7% of 1 of the insectivorous species and in 20.5% of the fruit bat species, but attempts to isolate virus were unsuccessful.

  14. Studies of Reservoir Hosts for Marburg virus

    DEFF Research Database (Denmark)

    Swanepoel, Robert; Smit, Sheilagh B; Rollin, Pierre E


    To determine reservoir hosts for Marburg virus (MARV), we examined the fauna of a mine in northeastern Democratic Republic of the Congo. The mine was associated with a protracted outbreak of Marburg hemorrhagic fever during 1998-2000. We found MARV nucleic acid in 12 bats, comprising 3.0%-3.6% of 2...... species of insectivorous bat and 1 species of fruit bat. We found antibody to the virus in the serum of 9.7% of 1 of the insectivorous species and in 20.5% of the fruit bat species, but attempts to isolate virus were unsuccessful. ...

  15. Location of Host and Host Habitat by Fruit Fly Parasitoids

    Directory of Open Access Journals (Sweden)

    Pascal Rousse


    Full Text Available Augmentative releases of parasitoids may be a useful tool for the area-wide management of tephritid pests. The latter are parasitized by many wasp species, though only a few of them are relevant for augmentative biocontrol purposes. To date, nearly all the actual or potential biocontrol agents for such programs are egg or larval Opiinae parasitoids (Hymenoptera: Braconidae. Here, we review the literature published on their habitat and host location behavior, as well as the factors that modulate this behavior, which is assumed to be sequential; parasitoids forage first for the host habitat and then for the host itself. Parasitoids rely on chemical, visual, and mechanical stimuli, often strongly related to their ecology. Behavioral modulation factors include biotic and abiotic factors including learning, climatic conditions and physiological state of the insect. Finally, conclusions and perspectives for future research are briefly highlighted. A detailed knowledge of this behavior may be very useful for selecting the release sites for both inundative/augmentative releases of mass-reared parasitoids and inoculative releases for classical biocontrol.

  16. Host preference of an introduced 'generalist' parasite for a non-native host. (United States)

    Frankel, Victor M; Hendry, Andrew P; Rolshausen, Gregor; Torchin, Mark E


    Parasites can invade new ecosystems if they are introduced with their native hosts or if they successfully infect and colonise new hosts upon arrival. Here, we ask to what extent an introduced parasite demonstrates specialisation among novel host species. Infection surveys across three field sites in Gatun Lake, Panama, revealed that the invasive peacock bass, Cichla monoculus, was more commonly infected by the introduced trematode parasite Centrocestus formosanus than were three other common cichlid fishes. Laboratory infection experiments were conducted to determine whether parasitism might be driven by differential encounter/exposure to parasites or by differential infection susceptibility/preference across different host species. These experiments were performed by controlling for parasite exposure in single host (compatibility) experiments and in mixed host (preference) experiments. In all cases, the peacock bass exhibited higher infection rates with viable metacercariae relative to the other potential fish hosts. Our experiments thus support that an introduced generalist parasite shows apparent specialisation on a specific novel host. Further studies are needed to determine whether these patterns of specialisation are the result of local adaptation following invasion by the parasite.

  17. Two new species of Gyrocotyle (Monogenea from Chimaerids (Holocephali))

    NARCIS (Netherlands)

    Land, van der J.; Dienske, H.


    INTRODUCTION Species of the genus Gyrocotyle are quite common intestinal parasites of chimaerids. As far as we now know, each parasite species is restricted to one host species. In each host species, however, a second and much rarer species of Gyrocotyle may occur besides the common one. The common

  18. Hebeloma species associated with Cistus. (United States)

    Eberhardt, Ursula; Beker, Henry J; Vila, Jordi; Vesterholt, Jan; Llimona, Xavier; Gadjieva, Rena


    The genus Hebeloma has a number of species highly specific to Cistus and others that occur with several host genera. This paper discusses the species of Hebeloma that appear to be ectomycorrhizal with Cistus, judging from their occurrence when Cistus is the only available host. The previously unknown species H. plesiocistum spec. nov. is described. We also provide a key to the known Hebeloma associates of Cistus. Molecular analyses based on ITS sequence data further illustrate the distinctness of the newly described species and difficulties in the species delimitation with view to H. erumpens. Specific associations with Cistus may have evolved more than once within the genus Hebeloma.

  19. Hosting anions. The energetic perspective. (United States)

    Schmidtchen, Franz P


    Hosting anions addresses the widely spread molecular recognition event of negatively charged species by dedicated organic compounds in condensed phases at equilibrium. The experimentally accessible energetic features comprise the entire system including the solvent, any buffers, background electrolytes or other components introduced for e.g. analysis. The deconvolution of all these interaction types and their dependence on subtle structural variation is required to arrive at a structure-energy correlation that may serve as a guide in receptor construction. The focus on direct host-guest interactions (lock-and-key complementarity) that have dominated the binding concepts of artificial receptors in the past must be widened in order to account for entropic contributions which constitute very significant fractions of the total free energy of interaction. Including entropy necessarily addresses the ambiguity and fuzziness of the host-guest structural ensemble and requires the appreciation of the fact that most liquid phases possess distinct structures of their own. Apparently, it is the perturbation of the intrinsic solvent structure occurring upon association that rules ion binding in polar media where ions are soluble and abundant. Rather than specifying peculiar structural elements useful in anion binding this critical review attempts an illumination of the concepts and individual energetic contributions resulting in the final observation of specific anion recognition (95 references).

  20. Geographical variation in host-ant specificity of the parasitic butterfly Maculinea alcon in Denmark

    DEFF Research Database (Denmark)

    Als, Thomas Damm; Nash, David Richard; Boomsma, J. J.


    1. Maculinea alcon uses three different species of Myrmica host ants along a north-south gradient in Europe. Based on this geographical variation in host ant use, Elmes et al. (1994) suggested that M. alcon might consist of three or more cryptic species or host races, each using a single and diff...

  1. First host record for the cleptoparasitic bee Rhathymus friesei Ducke (Hymenoptera, Apidae

    Directory of Open Access Journals (Sweden)

    Hugo A. Werneck


    Full Text Available The genus Rhathymus contains only obligatory cleptoparasitic species whose hosts belong to the genus Epicharis (Apidae, Centridini. Host information is available for only four of the 20 species of Rhathymus. In this note a new host record is added, in which the parasitism by R. friesei on nests of Epicharis (Epicharoides picta is documented.

  2. Uncovering Wolbachia diversity upon artificial host transfer.

    Directory of Open Access Journals (Sweden)

    Daniela I Schneider

    Full Text Available The common endosymbiotic Wolbachia bacteria influence arthropod hosts in multiple ways. They are mostly recognized for their manipulations of host reproduction, yet, more recent studies demonstrate that Wolbachia also impact host behavior, metabolic pathways and immunity. Besides their biological and evolutionary roles, Wolbachia are new potential biological control agents for pest and vector management. Importantly, Wolbachia-based control strategies require controlled symbiont transfer between host species and predictable outcomes of novel Wolbachia-host associations. Theoretically, this artificial horizontal transfer could inflict genetic changes within transferred Wolbachia populations. This could be facilitated through de novo mutations in the novel recipient host or changes of haplotype frequencies of polymorphic Wolbachia populations when transferred from donor to recipient hosts. Here we show that Wolbachia resident in the European cherry fruit fly, Rhagoletis cerasi, exhibit ancestral and cryptic sequence polymorphism in three symbiont genes, which are exposed upon microinjection into the new hosts Drosophila simulans and Ceratitis capitata. Our analyses of Wolbachia in microinjected D. simulans over 150 generations after microinjection uncovered infections with multiple Wolbachia strains in trans-infected lines that had previously been typed as single infections. This confirms the persistence of low-titer Wolbachia strains in microinjection experiments that had previously escaped standard detection techniques. Our study demonstrates that infections by multiple Wolbachia strains can shift in prevalence after artificial host transfer driven by either stochastic or selective processes. Trans-infection of Wolbachia can claim fitness costs in new hosts and we speculate that these costs may have driven the shifts of Wolbachia strains that we saw in our model system.

  3. Host plant utilization, host range oscillations and diversification in nymphalid butterflies: a phylogenetic investigation. (United States)

    Nylin, Sören; Slove, Jessica; Janz, Niklas


    It has been suggested that phenotypic plasticity is a major factor in the diversification of life, and that variation in host range in phytophagous insects is a good model for investigating this claim. We explore the use of angiosperm plants as hosts for nymphalid butterflies, and in particular the evidence for past oscillations in host range and how they are linked to host shifts and to diversification. At the level of orders of plants, a relatively simple pattern of host use and host shifts emerges, despite the 100 million years of history of the family Nymphalidae. We review the evidence that these host shifts and the accompanying diversifications were associated with transient polyphagous stages, as suggested by the "oscillation hypothesis." In addition, we investigate all currently polyphagous nymphalid species and demonstrate that the state of polyphagy is rare, has a weak phylogenetic signal, and a very apical distribution in the phylogeny; we argue that these are signs of its transient nature. We contrast our results with data from the bark beetles Dendroctonus, in which a more specialized host use is instead the apical state. We conclude that plasticity in host use is likely to have contributed to diversification in nymphalid butterflies. © 2013 The Authors. Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

  4. Bartonella entry mechanisms into mammalian host cells. (United States)

    Eicher, Simone C; Dehio, Christoph


    The Gram-negative genus Bartonella comprises arthropod-borne pathogens that typically infect mammals in a host-specific manner. Bartonella bacilliformis and Bartonella quintana are human-specific pathogens, while several zoonotic bartonellae specific for diverse animal hosts infect humans as an incidental host. Clinical manifestations of Bartonella infections range from mild symptoms to life-threatening disease. Following transmission by blood-sucking arthropods or traumatic contact with infected animals, bartonellae display sequential tropisms towards endothelial and possibly other nucleated cells and erythrocytes, the latter in a host-specific manner. Attachment to the extracellular matrix (ECM) and to nucleated cells is mediated by surface-exposed bacterial adhesins, in particular trimeric autotransporter adhesins (TAAs). The subsequent engulfment of the pathogen into a vacuolar structure follows a unique series of events whereby the pathogen avoids the endolysosomal compartments. For Bartonella henselae and assumingly most other species, the infection process is aided at different steps by Bartonella effector proteins (Beps). They are injected into host cells through the type IV secretion system (T4SS) VirB/D4 and subvert host cellular functions to favour pathogen uptake. Bacterial binding to erythrocytes is mediated by Trw, another T4SS, in a strictly host-specific manner, followed by pathogen-forced uptake involving the IalB invasin and subsequent replication and persistence within a membrane-bound intra-erythrocytic compartment.

  5. Host preference and suitability of grasses for Oebalus pugnax (United States)

    Awuni, GA; Gore, J; Cook, D; Bond, JA; Musser, FR; Adams, CA


    The rice stink bug, Oebalus pugnax (Fabricius) (Hemiptera: Pentatomidae: Carpocorini), though graminaceous, discriminates among its numerous host grass species. This could represent a feeding preference, it could be related to host suitability for growth and development. To clarify the role of host grass discrimination, two laboratory studies were conducted: (1) free-choice tests to evaluate preferences of O. pugnax among 11 wild host grass species found in three rice-producing counties of the central Mississippi Delta (MS, USA), and (2) no-choice tests to evaluate the impact of rice (Oryza sativa L.), junglerice [Echinochloa colona (L.) Link], and dallisgrass (Paspalum dilatatum Poir.) (all Poaceae), on the development of O. pugnax from second instar to adult. In the free-choice test, four experiments were conducted, each with four sets of host grass species and observed 1, 2, 4, 8, and 16 h after release in cages. Approximately 4 h was necessary for O. pugnax to settle on preferred host grasses. Oebalus pugnax showed a feeding preference for junglerice over all 10 other grass species. Bahiagrass, Paspalum notatum Flueggé, was the least preferred. The no-choice tests showed significant effect of host grass species on O. pugnax mean development time of nymphal survival to adults. Survival of nymphs was lower and mean development time was longer on dallisgrass compared to rice and junglerice. Knowledge of O. pugnax rate of growth and development on host grasses could be useful in the future development of rice integrated pest management strategies. PMID:25635144

  6. Evolution of host range in the follicle mite Demodex kutzeri. (United States)

    Palopoli, Michael F; Tra, VAN; Matoin, Kassey; Mac, Phuong D


    The sequences of four mitochondrial genes were determined for Demodex mites isolated from two distantly related species within the family Cervidae, and identified morphologically as belonging to the species Demodex kutzeri. The sequences were used to test the hypothesis that Demodex are strictly host-specific, and hence cospeciate with their hosts: (1) The estimated divergence time between mites found on elk vs humans agreed closely with a previous estimate of the time that these host species last shared a common ancestor, suggesting cospeciation of mites and hosts, at least over long evolutionary timescales. (2) The extremely low levels of sequence divergence between the mites found on elk vs mule deer hosts indicated that these mites belong to the same species, which suggests that Demodex are able to move across host species boundaries over shorter timescales. Together, the results are consistent with the model that Demodex mites are not strict host-specialists, but instead lose the ability to move between host lineages gradually.

  7. Galling Aphids (Hemiptera: Aphidoidea in China: Diversity and Host Specificity

    Directory of Open Access Journals (Sweden)

    Jing Chen


    Full Text Available Gall formation is an interesting plant response to aphid feeding. This paper presents a review of galling aphids in China. Altogether, 157 species and subspecies in ten families and subfamilies are found to induce galls on their host plants. As many as 39% species are endemic to China. The Eriosomatinae include the highest percentage of gall-inducing species. The great diversity of gall morphology may be described in terms of five characteristics: type, site, size, shape, and structure. The host association and host specificity of galling aphids are also discussed.

  8. The role of body size in host specificity: reciprocal transfer experiments with feather lice. (United States)

    Bush, Sarah E; Clayton, Dale H


    Although most parasites show at least some degree of host specificity, factors governing the evolution of specificity remain poorly understood. Many different groups of host-specific parasites show a striking correlation between parasite and host body size, suggesting that size reinforces specificity. We tested this hypothesis by measuring the relative fitness of host-specific feather lice transferred to pigeons and doves that differ in size by an order of magnitude. To test the general influence of size, we transferred unrelated groups of wing and body lice, which are specialized for different regions of the host. Lice were transferred in both directions, from a large native host species, the rock pigeon (Columba livia), to several progressively smaller hosts, and from a small native host species, the common ground dove (Columbina passerina), to several larger hosts. We measured the relative fitness (population size) of lice transferred to these novel host species after two louse generations. Neither wing lice nor body lice could survive on novel host species that were smaller in size than the native host. However, when host defense (preening behavior) was blocked, both groups survived and reproduced on all novel hosts tested. Thus, host defense interacted with host size to govern the ability of lice to establish on small hosts. Neither wing lice nor body lice could survive on larger hosts, even when preening was blocked. In summary, host size influenced the fitness of both types of feather lice, but through different mechanisms, depending on the direction of the transfer. Our results indicate that host switching is most likely between hosts of similar body size. This finding has important implications for studies of host-parasite coevolution at both the micro- and macroevolutionary scales.

  9. Citizen science data reveal ecological, historical and evolutionary factors shaping interactions between woody hosts and wood-inhabiting fungi. (United States)

    Heilmann-Clausen, Jacob; Maruyama, Pietro K; Bruun, Hans Henrik; Dimitrov, Dimitar; Laessøe, Thomas; Frøslev, Tobias Guldberg; Dalsgaard, Bo


    Woody plants host diverse communities of associated organisms, including wood-inhabiting fungi. In this group, host effects on species richness and interaction network structure are not well understood, especially not at large geographical scales. We investigated ecological, historical and evolutionary determinants of fungal species richness and network modularity, that is, subcommunity structure, across woody hosts in Denmark, using a citizen science data set comprising > 80 000 records of > 1000 fungal species on 91 genera of woody plants. Fungal species richness was positively related to host size, wood pH, and the number of species in the host genus, with limited influence of host frequency and host history, that is, time since host establishment in the area. Modularity patterns were unaffected by host history, but largely reflected host phylogeny. Notably, fungal communities differed substantially between angiosperm and gymnosperm hosts. Host traits and evolutionary history appear to be more important than host frequency and recent history in structuring interactions between hosts and wood-inhabiting fungi. High wood acidity appears to act as a stress factor reducing fungal species richness, while large host size, providing increased niche diversity, enhances it. In some fungal groups that are known to interact with live host cells in the establishment phase, host selectivity is common, causing a modular community structure. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  10. Constraints on host choice: why do parasitic birds rarely exploit some common potential hosts? (United States)

    Grim, Tomáš; Samaš, Peter; Moskát, Csaba; Kleven, Oddmund; Honza, Marcel; Moksnes, Arne; Røskaft, Eivin; Stokke, Bård G


    1. Why are some common and apparently suitable resources avoided by potential users? This interesting ecological and evolutionary conundrum is vividly illustrated by obligate brood parasites. Parasitic birds lay their eggs into nests of a wide range of host species, including many rare ones, but do not parasitize some commonly co-occurring potential hosts. 2. Attempts to explain the absence of parasitism in common potential hosts are limited and typically focused on single-factor explanations while ignoring other potential factors. We tested why thrushes Turdus spp. are extremely rarely parasitized by common cuckoos Cuculus canorus despite breeding commonly in sympatry and building the most conspicuous nests among forest-breeding passerines. 3. No single examined factor explained cuckoo avoidance of thrushes. Life-history traits of all six European thrush species and the 10 most frequently used cuckoo hosts in Europe were similar except body/egg size, nest design and nestling diet. 4. Experiments (n = 1211) in several populations across Europe showed that host defences at egg-laying and incubation stages did not account for the lack of cuckoo parasitism in thrushes. However, cross-fostering experiments disclosed that various factors during the nestling period prevent cuckoos from successfully parasitizing thrushes. Specifically, in some thrush species, the nest cup design forced cuckoo chicks to compete with host chicks with fatal consequences for the parasite. Other species were reluctant to care even for lone cuckoo chicks. 5. Importantly, in an apparently phylogenetically homogenous group of hosts, there were interspecific differences in factors responsible for the absence of cuckoo parasitism. 6. This study highlights the importance of considering multiple potential factors and their interactions for understanding absence of parasitism in potential hosts of parasitic birds. In the present study, comparative and experimental procedures are integrated, which

  11. MEDHOST: An encyclopedic bibliography of the host plants of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), version 1.1 (United States)

    This monograph is a compendium of all plant species reported as hosts of C. capitata (or potential hosts based on mere appearance on some lists). There are 353 species (312 have valid genera and species names and 41 have species identified as "sp." or "spp.") included in the monograph; 79 species ha...

  12. The path to host extinction can lead to loss of generalist parasites. (United States)

    Farrell, Maxwell J; Stephens, Patrick R; Berrang-Ford, Lea; Gittleman, John L; Davies, T Jonathan


    Host extinction can alter disease transmission dynamics, influence parasite extinction and ultimately change the nature of host-parasite systems. While theory predicts that single-host parasites are among the parasite species most susceptible to extinction following declines in their hosts, documented parasite extinctions are rare. Using a comparative approach, we investigate how the richness of single-host and multi-host parasites is influenced by extinction risk among ungulate and carnivore hosts. Host-parasite associations for free-living carnivores (order Carnivora) and terrestrial ungulates (orders Perissodactyla + Cetartiodactyla minus cetaceans) were merged with host trait data and IUCN Red List status to explore the distribution of single-host and multi-host parasites among threatened and non-threatened hosts. We find that threatened ungulates harbour a higher proportion of single-host parasites compared to non-threatened ungulates, which is explained by decreases in the richness of multi-host parasites. However, among carnivores threat status is not a significant predictor of the proportion of single-host parasites, or the richness of single-host or multi-host parasites. The loss of multi-host parasites from threatened ungulates may be explained by decreased cross-species contact as hosts decline and habitats become fragmented. Among carnivores, threat status may not be important in predicting patterns of parasite specificity because host decline results in equal losses of both single-host parasites and multi-host parasites through reduction in average population density and frequency of cross-species contact. Our results contrast with current models of parasite coextinction and highlight the need for updated theories that are applicable across host groups and account for both inter- and intraspecific contact.

  13. Varroa destructor changes its cuticular hydrocarbons to mimic new hosts. (United States)

    Le Conte, Y; Huang, Z Y; Roux, M; Zeng, Z J; Christidès, J-P; Bagnères, A-G


    Varroa destructor (Vd) is a honeybee ectoparasite. Its original host is the Asian honeybee, Apis cerana, but it has also become a severe, global threat to the European honeybee, Apis mellifera. Previous studies have shown that Varroa can mimic a host's cuticular hydrocarbons (HC), enabling the parasite to escape the hygienic behaviour of the host honeybees. By transferring mites between the two honeybee species, we further demonstrate that Vd is able to mimic the cuticular HC of a novel host species when artificially transferred to this new host. Mites originally from A. cerana are more efficient than mites from A. mellifera in mimicking HC of both A. cerana and A. mellifera. This remarkable adaptability may explain their relatively recent host-shift from A. cerana to A. mellifera.

  14. A combined parasitological molecular approach for noninvasive characterization of parasitic nematode communities in wild hosts (United States)

    Most hosts are concurrently or sequentially infected with multiple parasites, thus fully understanding interactions between individual parasite species and their hosts depends on accurate characterization of the parasite community. For parasitic nematodes, non-invasive methods for obtaining quantita...

  15. The evolution of host-specific variation in cuckoo eggshell strength. (United States)

    Spottiswoode, C N


    Cuckoo eggs are renowned for their mimicry of different host species, leading to the evolution of host-specific races (or 'gentes') defined by egg colour and pattern. This study aims to test the prediction that another property of parasitic eggs, namely shell strength, might also have experienced divergent selection within cuckoo species. Host races of the common cuckoo Cuculus canorus encountering stronger host rejection have thicker-shelled eggs than those parasitising less discriminating species, as expected if egg strengthening discourages host rejection. Moreover, in the diederik cuckoo Chrysococcyx caprius, eggshell thickness was correlated across cuckoo gentes and host species, as expected if eggshell strength has been involved in coevolutionary interactions. This is the first report of host-specific differences in cuckoo egg properties other than colour and pattern and lends correlational support to the hypothesis that the strong eggshells of brood parasites are an adaptation to reduce host rejection.

  16. Host preferences in host-seeking and blood-fed mosquitoes in Switzerland. (United States)

    Schönenberger, A C; Wagner, S; Tuten, H C; Schaffner, F; Torgerson, P; Furrer, S; Mathis, A; Silaghi, C


    The avian zoonotic agent for West Nile virus (WNV) can cause neuroinvasive disease in horses and humans and is expanding its range in Europe. Analyses of the risk for transmission to these hosts in non-endemic areas are necessary. Host preferences of mosquitoes (Diptera: Culicidae), the main vectors of WNV, were determined in Switzerland using animal-baited trap (horse, chickens) experiments at a natural and a periurban site. This was undertaken on four occasions during May-September 2014. In addition, the hosts of 505 blood-fed mosquitoes collected in a zoo and in the field were determined. Mosquito data obtained in the animal bait experiments were corrected for host weight and body surface area and by Kleiber's scaling factor. Collections of 11-14 different mosquito species were achieved with these approaches. Statistically significant host preferences were identified in three species in both approaches. The other species showed opportunistic feeding behaviours to varying extents. Specifically, the invasive species Hulecoeteomyia japonica (= Aedes japonicus) was identified for the first time as feeding on avians in nature. Abundance data, spatiotemporal activity and laboratory vector competence for WNV suggested that, in addition to the main WNV vector Culex pipiens, H. japonica and Aedimorphus vexans (= Aedes vexans) are the most likely candidate bridge vectors for WNV transmission in Switzerland.

  17. Host body size and the diversity of tick assemblages on Neotropical vertebrates

    Directory of Open Access Journals (Sweden)

    Helen J. Esser


    Full Text Available Identifying the factors that influence the species diversity and distribution of ticks (Acari: Ixodida across vertebrate host taxa is of fundamental ecological and medical importance. Host body size is considered one of the most important determinants of tick abundance, with larger hosts having