536 resultados para Mites.
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"July 1937."
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Binder's title: Juicio de límites entre el Perú y Bolivia. Exposición de la república del Perú...1906.
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Mode of access: Internet.
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Mode of access: Internet.
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The Linotetranidae (Acari: Tetranychoidea) is a poorly known group of cryptic false spider mites associated with grasses and sedges. We review the family at the world level, provide the first phylogenetic analysis of the family, and describe the first Australian representatives: Austrolinus, gen. nov. and two new species: A. arenulus and A. kinnearae. Linotetranidae is redefined, and keys are provided for the families of the Tetranychoidea, and for all described genera and species of Linotetranidae.
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Predatory mites (Acari: Mesostigmata) on tree trunks without significant epiphytic growth in a subtropical rainforest in Eastern Australia were assessed for habitat specificity (i.e. whether they are tree trunk specialists or occupying other habitats) and the influence of host tree and bark structure on their abundance, species richness and species composition. The trunks of nine tree species from eight plant families representing smooth, intermediate and rough bark textures were sampled using a knockdown insecticide spray. In total, 12 species or morphospecies of Mesostigmata (excluding Uropodina sensu stricto) were collected, most of which are undescribed. Comparison with collections from other habitats indicates that epicorticolous Mesostigmata are mainly represented by suspended soil dwellers (six species), secondarily by generalists (four species) and a bark specialist (one species). A typical ground-dwelling species was also found but was represented only by a single individual. In terms of abundance, 50.5% of individuals were suspended soil dwellers, 40.7% bark specialists, and 8.3% generalists. Host species and bark roughness had no significant effect on abundance or species richness. Furthermore, there was no clear effect on species composition. The distribution of the most frequently encountered species suggests that most mesostigmatid mites living on bark use many or most rainforest tree species, independent of bark roughness. These findings support the hypothesis that some epicorticolous Mesostigmata use tree trunks as 'highways' for dispersing between habitat patches, while others use it as a permanent habitat.
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The gene content of a mitochondrial (mt) genome, i.e., 37 genes and a large noncoding region (LNR), is usually conserved in Metazoa. The arrangement of these genes and the LNR is generally conserved at low taxonomic levels but varies substantially at high levels. We report here a variation in mt gene content and gene arrangement among chigger mites of the genus Leptotrombidium. We found previously that the mt genome of Leptotrombidium pallidum has an extra gene for large-subunit rRNA (rrnL), a pseudo-gene for small-subunit rRNA (PrrnS), and three extra LNRs, additional to the 37 genes and an LNR typical of Metazoa. Further, the arrangement of mt genes of L. pallidum differs drastically from that of the hypothetical ancestor of the arthropods. To find to what extent the novel gene content and gene arrangement occurred in Leptotrombidium, we sequenced the entire or partial mt genomes of three other species, L. akamushi, L. deliense, and L. fletcheri. These three species share the arrangement of all genes with L. pallidum, except trnQ (for tRNA-glutamine). Unlike L. pallidum, however, these three species do not have extra rrnL or PrrnS and have only one extra LNR. By comparison between Leptotrombidium species and the ancestor of the arthropods, we propose that (1) the type of mt genome present in L. pallidum evolved from the type present in the other three Leptotrombidium species, and (2) three molecular mechanisms were involved in the evolution of mt gene content and gene arrangement in Leptotrombidium species.
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This review discusses the connection between quantitative changes of environmental factors and oribatid communities. With the overview of available studies, it can be clearly explored how various characteristics of Oribatid communities are modified due to changes in moisture, temperature, heavy metal concentration, organic matter content and level of disturbance. The most important question concerning the application of Oribatids as indicators is to clarify what kind of information content does natural Oribatid coenological patterns possess from the aspect of bioindication. Most of the variables listed above can be directly measured, since rapid methods are available to quantify parameters of the soil. Responses of Oribatids are worth to study in a more complex approach. Even now we have an expansive knowledge on how communities change due to modifications of different factors. These pieces of information necessitate the elaboration of such methods which render Oribatid communities suitable for the task to prognosticate what extent the given site can be considered near-natural or degraded, based on the Oribatid composition of a single sample taken from the given area. Answering this problem needs extensive and coordinated work.
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Oribatid mites are one of the most abundant and species rich group in soil mesofauna. In spite of this, we have limited knowledge on the role they play in ecological processes. Since they are small like other mesofauna members and live a hidden life, their observation is difficult. Their life style, interactions with other organisms and role in soil decomposition processes can be investigated with laboratory experiments more exactly and effectively. While the literature of microcosm studies is very extensive, relatively few review papers have been written about the methodology of microcosm studies. The present review summarizes details of techniques that have been applied laboratory microcosms involving oribatid mites. It is shown what one should keep in mind in planning, composing and setting up a microcosm. Our comparative evaluation reveals how the laboratory experiments were maintained and manipulated and what kind of information was extracted. This methodological review can be useful in preparing microcosm experiments applied to other animal groups as well.