Mesostigmatid Mites (Acari: Mesostigmata) on Rainforest Tree Trunks: Arboreal Specialists, but Substrate Generalists?

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.     

Major lineages of Nolidae (Lepidoptera,Noctuoidea) elucidated by molecular phylogenetics

To elucidate the evolutionary relationships of the major lineages within the moth family Nolidae, we analysed a molecular dataset comprising eight independent gene regions (6.4 kbp), cytochrome c oxidase subunit I (COI) from the mitochondrial genome, and elongation factor‐1α (EF‐1α), ribosomal protein S5 (RpS5), carbamoylphosphate synthase domain protein (CAD), cytosolic malate dehydrogenase (MDH), glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH), isocitrate dehydrogenase (IDH) and wingless genes from the nuclear genome, using parsimony and model‐based evolutionary methods (maximum likelihood and Bayesian inference). Our analyses revealed a well‐resolved phylogenetic hypothesis, again recovering the six previously recognized families within Noctuoidea (i.e. Oenosandridae, Notodontidae, Euteliidae, Erebidae, Nolidae and Noctuidae), and monophyly of the quadrifid Noctuoidea (i.e. Euteliidae, Erebidae, Nolidae and Noctuidae). The family Nolidae is diagnosed and characterized by two synapomorphies from morphology: construction of a ridged boat‐shaped cocoon that bears a vertical exit slit at one end; and two other morphological character states: elongation of the forewing retinaculum into a bar‐like or digitate condition and possession of a postpiracular counter‐tympanal hood. We present a new phylogenetic hypothesis for Nolidae consisting of eight strongly supported subfamilies, two of which are erected here: Diphtherinae, Risobinae, Collomeninae subfam. nov., Beaninae subfam. nov., Eligminae, Westermanniinae, Nolinae and Chloephorinae. Where we are able, each monophyletic lineage is diagnosed by morphological autapomorphies and within each subfamily, monophyletic tribes and subtribes are circumscribed, most of which are also diagnosable by morphological apomorphies. We also describe two new taxa: Gelastocerini trib. nov. and Etannina subtrib. nov. The Neotropical subfamily Diphtherinae, here newly circumscribed, is considered to be the plesiomorphic sister lineage to the rest of Nolidae. Diphtherinae are characterized by loss of the proximal pair of metatibial spurs in males and by the presence of a frontal tubercle, which is presumably associated with a derived strategy of emergence from the cocoon.     

Reliable,verifiable and efficient monitoring of biodiversity via metabarcoding

To manage and conserve biodiversity, one must know what is being lost, where, and why, as well as which remedies are likely to be most effective. Metabarcoding technology can characterise the species compositions of mass samples of eukaryotes or of environmental DNA. Here, we validate metabarcoding by testing it against three high‐quality standard data sets that were collected in Malaysia (tropical), China (subtropical) and the United Kingdom (temperate) and that comprised 55,813 arthropod and bird specimens identified to species level with the expenditure of 2,505 person‐hours of taxonomic expertise. The metabarcode and standard data sets exhibit statistically correlated alpha‐ and beta‐diversities, and the two data sets produce similar policy conclusions for two conservation applications: restoration ecology and systematic conservation planning. Compared with standard biodiversity data sets, metabarcoded samples are taxonomically more comprehensive, many times quicker to produce, less reliant on taxonomic expertise and auditable by third parties, which is essential for dispute resolution.     

The web and the structure of taxonomy

An easily accessible taxonomic knowledge base is critically important for all biodiversity-related sciences. At present, taxonomic information is organized and regulated by a system of rules and conventions that date back to the introduction of binomial nomenclature by Linnaeus. The taxonomy of any particular group of organisms comprises the sum information in the taxonomic literature, supported by designated type specimens in major collections. In this article, the way modern means of disseminating information will change the practice of taxonomy, in particular the Internet, is explored. Basic taxonomic information, such as specimen-level data, location of types, and name catalogues are already available, at least for some groups, on the Web. Specialist taxonomic databases, key-construction programs, and other software useful for systematists are also increasingly available. There has also been a move towards Web-publishing of taxonomic hypotheses, though as yet this is not fully permitted by the Codes of Nomenclature. A further and more radical move would be to transfer taxonomy completely to the Web. A possible model of this is discussed, as well as a pilot project, the "CATE" initiative, which seeks to explore the advantages and disadvantages of such a move. It is argued that taxonomy needs to forge better links with its user-communities to maintain its funding base, and that an important part of this is making the products of its research more accessible through the Internet.     

Fungal biosynthesis of gold nanoparticles: mechanism and scale up

Gold nanoparticles (AuNPs) are a widespread research tool because of their oxidation resistance, biocompatibility and stability. Chemical methods for AuNP synthesis often produce toxic residues that raise environmental concern. On the other hand, the biological synthesis of AuNPs in viable microorganisms and their cell-free extracts is an environmentally friendly and low-cost process. In general, fungi tolerate higher metal concentrations than bacteria and secrete abundant extracellular redox proteins to reduce soluble metal ions to their insoluble form and eventually to nanocrystals. Fungi harbour untapped biological diversity and may provide novel metal reductases for metal detoxification and bioreduction. A thorough understanding of the biosynthetic mechanism of AuNPs in fungi is needed to reduce the time of biosynthesis and to scale up the AuNP production process. In this review, we describe the known mechanisms for AuNP biosynthesis in viable fungi and fungal protein extracts and discuss the most suitable bioreactors for industrial AuNP biosynthesis.     

Component analysis and modelling of the movement process: Analysis of simple tracks

The construction of a general model of animal movement using the ‘experimental components' approach ofC. S. Holling is proposed. The process of ‘movement’ is interpreted very generally as any displacement of the whole organism in space. The rationale for modelling such processes rests upon the idea that there is a basic “canonical” pattern of movement characteristic of a species moving in a homogeneous environment, which pattern is overlaid by the various directional stimuli present in more usual heterogeneous environments. The ‘canonical movement model’ is a necessary first step in construction of more realistic representations. We suggest it can be made using six components viz. the initial heading of the animal, the mean and variance of the angular displacements made by the animal as it moves, the mean and variance of the speed of the animal, and a term for the continuity of the movement. We have measured all these components in the field for the two-dimensional movement of the inter-tidal snail, Polinices incei and these results are presented here. Difficulties inherent in the measure ment of angular displacement in particular are discussed and means of resolving them proposed. The shortcomings involved in the measurements and techniques for their more detailed representation and the next steps in the proposed modelling sequence are discussed.     

Vertical stratification of rainforest collembolan (Collembola: Insecta) assemblages: description of ecological patterns and hypotheses concerning their generation

We describe a complex vertical stratification of collembolan assemblages from rainforest leaf litter samples and identify distinct assemblages associated with forest floor, lower canopy and upper canopy samples. Leaf litter samples were collected from the forest floor and deposits of leaf litter suspended in epiphytes in the canopy of a subtropical rainforest site at Lamington National Park in southeast Queensland. The patterns of relationship among assemblages of Collembola extracted from these samples were examined using a variety of analyses of a matrix of similarities between samples. The results of ANOSIM analyses showed that forest floor, lower canopy and tipper canopy samples formed discrete groups. These results permit a discussion of these groups as three distinct collembolan assemblages. Analysis of the dissimilarities between these assemblages revealed a gradient of similarity from the forest floor through the lower to the upper canopy. This gradient represents a more complex vertical stratification than has previously been identified in rainforest canopy arthropods. We suggest that limitations on the dispersal of some forest floor species into the canopy may be responsible for this pattern. We also identify a second gradient of similarities among these assemblages. We show that dissimilarity among samples from forest floor is significantly lower than dissimilarity among samples from within the lower canopy, and that the level of dissimilarity between samples from within the upper canopy is significantly higher again. We suggest that dispersal barriers and higher probabilities of extinction in upper canopy collembolan colonies may be responsible for higher heterogeneity of species composition and abundance among samples from the upper canopy. We outline a number of testable hypotheses aimed at determining the importance of these processes in producing the patterns we have observed.     

Putting insects on the map: near‐global variation in sphingid moth richness along spatial and environmental gradients

Despite their vast diversity and vital ecological role, insects are notoriously underrepresented in biogeography and conservation, and key broad‐scale ecological hypotheses about them remain untested – largely due to generally incomplete and very coarse spatial distribution knowledge. Integrating records from publications, field work and natural history collections, we used a mixture of species distribution models and expert estimates to provide geographic distributions and emergent richness patterns for all ca 1000 sphingid moth species found outside the Americas in high spatial detail. Total sphingid moth richness, the first for a higher insect group to be documented at this scale, shows distinct maxima in the wet tropics of Africa and the Oriental with notable decay toward Australasia. Using multivariate models controlling for spatial autocorrelation, we found that primary productivity is the dominant environmental variable associated with moth richness, while temperature, contrary to our predictions, is an unexpectedly weak predictor. This is in stark contrast to the importance we identify for temperature as a niche variable of individual species. Despite divergent life histories, both main sub‐groups of moths exhibit these relationships. Tribal‐level deconstruction of richness and climatic niche patterns indicate idiosyncratic effects of biogeographic history for some of the less species‐rich tribes, which in some cases exhibit distinct richness peaks away from the tropics. The study confirms, for a diverse insect group, overall richness associations of remarkable similarity to those documented for vertebrates and highlights the significant within‐taxon structure that underpins emergent macroecological patterns. Results do not, however, meet predictions from vertebrate‐derived hypotheses on how thermoregulation affects the strength of temperature–richness effects. Our study thus broadens the taxonomic focus in this data‐deficient discourse. Our procedures of processing incomplete, scattered distribution data are a template for application to other taxa and regions.