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Viral metagenomics and high throughput sequence mining have revealed unexpected diversity, and the potential presence, of parvoviruses in animals from all phyla. Among arthropods, this diversity highlights the poor knowledge that we have regarding the evolutionary history of densoviruses. The aim of this study was to explore densovirus diversity in a small arthropod pest belonging to Acari, the two-spotted spider mite Tetranychus urticae, while using viral metagenomics based on virus-enrichment. Here, we present the viromes obtained from T. urticae laboratory populations made of contigs that are attributed to nine new potential viral species, including the complete sequence of a novel densovirus. The genome of this densovirus has an ambisens genomic organization and an unusually compact size with particularly small non-structural proteins and a predicted major capsid protein that lacks the typical PLA2 motif that is common to all ambidensoviruses described so far. In addition, we showed that this new densovirus had a wide prevalence across populations of mite species tested and a genomic diversity that likely correlates with the host phylogeny. In particular, we observed a low densovirus genomic diversity between the laboratory and natural populations, which suggests that virus within-species evolution is probably slower than initially thought. Lastly, we showed that this novel densovirus can be inoculated to the host plant following feeding by infected mites, and circulate through the plant vascular system. These findings offer new insights into densovirus prevalence, evolution, and ecology.

Viral metagenomics and high throughput sequence mining have revealed unexpected diversity, and the potential presence, of parvoviruses in animals from all phyla. Among arthropods, this diversity highlights the poor knowledge that we have regarding the evolutionary history of densoviruses. The aim of this study was to explore densovirus diversity in a small arthropod pest belonging to Acari, the two-spotted spider mite Tetranychus urticae, while using viral metagenomics based on virus-enrichment. Here, we present the viromes obtained from T. urticae laboratory populations made of contigs that are attributed to nine new potential viral species, including the complete sequence of a novel densovirus. The genome of this densovirus has an ambisens genomic organization and an unusually compact size with particularly small non-structural proteins and a predicted major capsid protein that lacks the typical PLA2 motif that is common to all ambidensoviruses described so far. In addition, we showed that this new densovirus had a wide prevalence across populations of mite species tested and a genomic diversity that likely correlates with the host phylogeny. In particular, we observed a low densovirus genomic diversity between the laboratory and natural populations, which suggests that virus within-species evolution is probably slower than initially thought. Lastly, we showed that this novel densovirus can be inoculated to the host plant following feeding by infected mites, and circulate through the plant vascular system.These findings offer new insights into densovirus prevalence, evolution, and ecology.

Nepenthes pitcher plants are carnivorous plants that paradoxically harbor a living infauna (the inquilines) in their pitchers, which withstands the hostile conditions of the digestive fluid and plays a role in prey digestion. Because most Nepenthes species are threatened by human activity, we aimed to assess how their inquiline communities are likewise endangered. This involved testing whether arthropod infaunal composition is Nepenthes-specific or even species-specific, as well as determining the ecological drivers of its diversity. In a field experiment in Brunei (Borneo), prey items were introduced into the fluid of newly open pitchers in four sympatric Nepenthes species, and into water control reservoirs. Abundance, species richness and Shannon diversity of metazoans in all reservoirs were analyzed 1 month later. Reservoir dimensions and fluid pH were measured, and the natural prey and vegetal detritus were identified and quantified. The inquiline diversities of the Nepenthes pitchers were much greater than those of the water controls. Dissimilarity indices showed that the inquiline composition was specific to each Nepenthes species. The fate of the inquiline community is thus intrinsically linked to that of its host plant, underlining its threatened status. Inquiline abundance was determined by pitcher aperture diameter, pitcher volume, fluid pH and the prey number. Inquiline species richness increased solely with abiotic factors, such as fluid pH and pitcher aperture diameter, and thereby with habitat area, reflecting the well-known species–area relationship, but it did not vary with species richness of prey. Nepenthes pitcher plants thus control, to some extent, the establishment of their inquilines via fluid physico-chemistry and pitcher design. From a conservation perspective, priority protection should be given to Nepenthes species with pitchers of large aperture, keystone for a broader biodiversity.

Partie 3 : Douglas-fir ecology; International audience

UMR BFP - Equipe Mollicutes; International audience; Spiroplasmas are bacteria that do not possess flagella and their motility is linked to kink propagation coupled to changes in the cell body helicity. While the motility of bacteria with flagellar motion has been studied extensively, less work has been devoted to the motility of spiroplasmas. We first show that the motility of such bacteria has large variability from individual to individual as well as large fluctuations in time. The Brownian motion of such bacteria both in orientation and translation is also highlighted. We propose a simple model to disentangle the different components of this motility by examining trajectories of single bacteria in different viscosity solvents. The mean velocity of the bacteria turns out to depend on the viscosity of the medium as it increases with viscosity. Further, the temporal fluctuations of the bacteria motility turn out to be very strong with a direct link to tumbling events particular to this bacteria.

International audience; In poikilotherms, developmental time and adult lifespan are biological traits driven by temperature although their underlying physiological mechanisms differ. The developmental theory of ageing predicts a positive correlation between these two traits without confirming a genetic or causal relationship. The developmental rate isomorphy hypothesis established that the proportionality in the duration of each pre-imaginal stage with respect to total developmental time does not vary with temperature. This may have important evolutionary implications. We conducted an analysis with arthropods of agronomic interest to study if the hypothesis could be extended to the total lifespan of poikilotherms, including adult lifespan. We showed that isomorphy could be acceptable for a global description of this relationship. However a general model of power law type is more appropriate for characterizing the relationship between developmental time and adult lifespan. In this model, the shape of the curve is a constant characteristic, but the parameters that control it depend on the functional type of the arthropod (phytophagous, predator or parasitoid). Presumably this power law could be extended to all arthropods of agricultural interest, and more generally to all arthropod.

Viral metagenomic approaches have become essential for culture-independent and sequence-independent viral detection and characterization. This chapter describes an accurate and efficient approach to (1) concentrate viral particles from arthropods and plants, (2) remove contaminating non-encapsidated nucleic acids, (3) extract and amplify both viral DNA and RNA, and (4) analyze high-throughput sequencing (HTS) data by bioinformatics. Using this approach, up to 96 arthropod or plant samples can be multiplexed in a single HTS library.

We conducted a research about communication skill of secondary biology student in Arthropode classification using phenetic method. Data were obtained from written report and oral presentation. There were five indicators used to analyze communication skill in oral presentation, which included their ability to express opinion themselves and hearing the opinion from other, their ability to master the concept to be presented, their ability to communicate of results systematically and clearly, their ability to question, and their ability to answer. Five indicators used in written report were their ability to choose informative character to build fenogram, their ability to undergo step by step, resulted phenogram, their ability to interpret the results, and their ability to make a report. Results showed that communication skill in oral were good enough (63.75%), but low (56.25%) in written. Based on interview, however, students felt comfortable when teacher used the phenetic method to understand classification of Arthropode. This method has markedly stimulated the students to study actively in the classroom.Keywords: arthropode, communication skill, classification, phenetic method

Among arthropods, ability to survive cold conditions may be instrumental for species invading temperate or colder climatic zones. Cold tolerance can be influenced by multiple environmental and physiological factors. We experimentally investigated the effects of mating status (unmated, mated, or mated and reproductive) on cold tolerance of the invasive harlequin ladybird Harmonia axyridis and subsequent reproduction. We found that unmated adults survive cold better than mated ones. Among mated individuals, those that had not reproduced survived better than those that had reproduced. After cold stress, formerly unmated females were mated, and we evaluated ability to reproduce in females from all three treatments. Females that reproduced prior to cold stress were less likely to reproduce after cold stress than females from both other treatments. We discuss what these results mean for the proportion of unmated females in H. axyridis aggregates at overwintering sites. This study highlights the importance of investigating how physiological status can affect cold tolerance of invasive arthropods.

Ecological studies are increasingly moving towards trait-based approaches, as the evidence mounts that functions, as opposed to taxonomy, drive ecosystem service delivery. Among ecosystem services, biological control has been somewhat overlooked in functional ecological studies. This is surprising given that, over recent decades, much of biological control research has been focused on identifying the multiple characteristics (traits) of species that influence trophic interactions. These traits are especially well developed for interactions between arthropods and flowers - important for biological control, as floral resources can provide natural enemies with nutritional supplements, which can dramatically increase biological control efficiency. Traits that underpin the biological control potential of a community and that drive the response of arthropods to environmental filters, from local to landscape-level conditions, are also emerging from recent empirical studies. We present an overview of the traits that have been identified to (i) drive trophic interactions, especially between plants and biological control agents through determining access to floral resources and enhancing longevity and fecundity of natural enemies, (ii) affect the biological control services provided by arthropods, and (iii) limit the response of arthropods to environmental filters, ranging from local management practices to landscape-level simplification. We use this review as a platform to outline opportunities and guidelines for future trait-based studies focused on the enhancement of biological control services.

The repeated use of conventional synthetic pesticides in crop protection leads to resistance development by pests along with a negative impact on the environment, particularly non-target arthropods. Plant-derived active compounds, such as essential oils (EOs), play a key role in sustainably controlling pests. The lethal and sublethal activity of citrus peel EOs as emulsions and included in polyethylene glycol (PEG) nanoparticles (EO-NPs) was determined against the invasive tomato pest Tuta absoluta. Their effects on the plants were also assessed. The results showed an overall good insecticidal activity of the compounds tested, with a higher mortality through contact on eggs and larvae by EO emulsions and through ingestion on larvae by EO-NPs. The nanoformulation also significantly reduced the visible toxic effects on the plants. The data collected suggest that these natural compounds, especially when nanoformulated, could be successfully used in integrated pest management programs for T. absoluta.

10. International Symposium on Modelling in Fruit Research and Orchard Management Location: Montpellier, FRANCE Date: JUN 05, 2015; Orchards represent relevant study systems for investigating the functional role of insectivorous birds as regulators of pest insect populations. In this context, we used a bioenergetics model (Wiens and Innis, 1974) to estimate the seasonal variation in daily insect consumption by natural populations of the great tit (Parus major) in organic apple orchards. This model allowed us to estimate the changes in both adult densities and energy requirements in a P. major population, using field-measured parameters such as the brood size, and the length of incubation. The calculation of insect consumption rate by birds was based on both the existing literature on great tit diets and the simulated energy requirement of a great tit population. The effect of a temperature increase on energy requirement has been quantified. This study opens the way to consider the functional role of birds in agricultural landscapes and how this role may translate to ecosystem services.

Endogenous jasmonates are important regulators of plant defenses. If and how they enable plants to maintain their reproductive output when facing community-level herbivory under natural conditions, however, remains unknown. We demonstrate that jasmonate-deficient Nicotiana attenuata plants suffer more damage by arthropod and vertebrate herbivores than jasmonate-producing plants in nature. However, only damage by vertebrate herbivores translates into a significant reduction in flower production. Vertebrate stem peeling has the strongest negative impact on plant flower production. Stems are defended by jasmonate-dependent nicotine, and the native cottontail rabbit Sylvilagus nuttallii avoids jasmonate-producing N. attenuata shoots because of their high levels of nicotine. Thus, endogenous jasmonates enable plants to resist different types of herbivores in nature, and jasmonate-dependent defenses are important for plants to maintain their reproductive potential when facing vertebrate herbivory. Ecological and evolutionary models on plant defense signaling should aim at integrating arthropod and vertebrate herbivory at the community level. DOI: http://dx.doi.org/10.7554/eLife.13720.001, eLife digest Plants are attacked by many different herbivores, including insects and mammals, and often produce toxins in response to protect themselves. Toxin production is regulated by plant hormones called jasmonates. It is commonly assumed this ability helps plants to survive and reproduce in nature. However, proof that a plant's own jasmonates (also known as "endogenous jasmonates") can increase a plant's fitness in the wild is lacking, especially in the context of attack by mammals. Machado et al. have now asked whether endogenous jasmonates increase the fitness of coyote tobacco plants that were under attack by herbivores in their natural habitats in Southwestern Utah. Plants that lacked jasmonates were attacked more strongly by various herbivores, yet unexpectedly only the damage by mammals – including gophers, deer and rabbits – caused the plants to produce fewer flowers. Since plants with more flowers tend to produce more offspring, the number of flowers is a measure of a plant’s fitness. Damage by insects, which are often seen as major enemies of plants, did not result in a significant impact on the number of flowers. Laboratory experiments then revealed that damaging plants in a similar way to mammalian herbivores strongly reduced the plants’ fitness. However mimicking insect damage did not have such a large effect. Finally, feeding experiments with cottontail rabbits revealed that jasmonate-producing plants are protected by higher levels of the nicotine toxin, which can explain why these plants fare better when attacked by mammals in nature. Jasmonates are well known to regulate plant defenses and provide protection against a wide variety of herbivores. However, these new findings show that this only translates into fitness benefits for the plants against a subset of herbivores. A major challenge in the future will be to study how diverse communities of herbivores shape the evolution of plant defense signaling. Including larger herbivores, like mammals, into such experiments will be challenging but necessary to understand how plants survive in nature. DOI: http://dx.doi.org/10.7554/eLife.13720.002

In mammals, detection of osmolarity by the gustatory system was overlooked until recently. In insects, specific taste receptor neurons detect hypoosmotic stimuli and are commonly called "W" (water) cells. W cells are easy to access in vivo and represent a good model to study the transduction of hypoosmotic stimuli. Using pharmacological and genetic approaches in Drosophila, we show that tarsal W cell firing activity depends on the concentration of external calcium bathing the dendrite. This dependence was confirmed by the strong inhibition of W cell responses to hypoosmotic stimuli by lanthanum (IC(50) = 8 nM), an ion known to inhibit calcium-permeable channels. Downstream, the transduction pathway likely involves calmodulin because calmodulin antagonists such as W-7 (IC(50) = 2 microM) and fluphenazine (IC(50) = 30 microM) prevented the activation of the W cell by hypoosmotic stimuli. A protein kinase C (PKC) may also be involved as W cell responses were blocked by PKC inhibitors, chelerythrine (IC(50) = 20 microM) and staurosporine (IC(50) = 30 microM). It was also reduced when expressing an inhibitory pseudosubstrate of PKC in gustatory receptor neurons. In the rat, the transduction pathway underlying low osmolarity detection involves aquaporin and swelling-activated ion channels. Our study suggests that the transduction pathway of hypoosmotic stimuli in insects differs from mammals.

Densoviruses (DVs) are parvoviruses of arthropods and causative agents of natural epizootics in insects and crustaceans populations. Structurally simple, these small DNA viruses, display a large diversity of genomic sequences, structures and organizations. Such diversity, together with the diversity of their invertebrate hosts, from shrimps to mosquitoes and recently including sea stars, suggests that DVs are largely unknown and ubiquitous in the environment. Densoviruses are considered as a model of choice to study virus-host interactions and their evolution at different scales, from individuals to populations. This review summarizes the knowledge on densovirus biology obtained through mechanistic and global approaches. Finally, the potential use of these viruses as biological control agents against insect pests and disease-vectors are exposed.; Les densovirus (DV) sont des parvovirus d’arthropodes responsables d’épizooties chez les insectes et les crustacés. Structurellement simples, ces petits virus à ADN présentent une grande diversité de séquences et d’organisations génomiques, diversité probablement sous-estimée au regard des récentes découvertes de ces virus dans des hôtes inattendus. Les densovirus représentent un modèle de choix pour étudier à différentes échelles les interactions virus-hôtes et leurs évolutions. Nous proposons de revisiter les connaissances fondamentales sur les densovirus qui ont essentiellement été établies par des approches mécanistiques et envisageons les nouvelles perspectives d’études permises par des approches plus globales. Pour conclure, nous décrivons les applications possibles de ces virus comme outils biologiques, notamment pour le contrôle de populations d’insectes dits « nuisibles ».

International audience

International audience; Most species in the order Hymenoptera are parasitoids that lay eggs and develop in or on the body of arthropod hosts. Several factors contribute to successful parasitism including venoms that wasps inject into hosts when ovipositing. Here, we review the composition, function and diversity of parasitoid venoms with emphasis on studies of wasps that parasitize hosts in the genus Drosophila. The comparative literature indicates that some closely related species parasitizing the same host do not share any abundant venom protein while unrelated species sometimes have the same major venom component. Within species, studies also identify intraspecific variation that suggests parasitoid venoms may rapidly evolve. Overall, however, our picture of venom function remains largely unclear and will require additional comparative data on the composition of venoms from a greater diversity of species than exists currently. Further advances will come mainly from experimental data using functional tools, such as RNA interference.

Cyanogenic glucosides are among the most widespread defense chemicals of plants. Upon plant tissue disruption, these glucosides are hydrolyzed to a reactive hydroxynitrile that releases toxic hydrogen cyanide (HCN). Yet many mite and lepidopteran species can thrive on plants defended by cyanogenic glucosides. The nature of the enzyme known to detoxify HCN to β-cyanoalanine in arthropods has remained enigmatic. Here we identify this enzyme by transcriptome analysis and functional expression. Phylogenetic analysis showed that the gene is a member of the cysteine synthase family horizontally transferred from bacteria to phytophagous mites and Lepidoptera. The recombinant mite enzyme had both β-cyanoalanine synthase and cysteine synthase activity but enzyme kinetics showed that cyanide detoxification activity was strongly favored. Our results therefore suggest that an ancient horizontal transfer of a gene originally involved in sulfur amino acid biosynthesis in bacteria was co-opted by herbivorous arthropods to detoxify plant produced cyanide. DOI: http://dx.doi.org/10.7554/eLife.02365.001, eLife digest Hydrogen cyanide is a poison that is deadly for most forms of life. Also known as prussic acid, it has killed countless humans throughout history in accidents and during the Holocaust. Hydrogen cyanide is also used by plants to defend themselves against insects and other herbivorous animals. Many plants produce chemicals called cyanogenic glycosides that can be converted into hydrogen cyanide when the plant is eaten. This is an ancient and efficient defense against all sorts of herbivores, including humans. For instance, cassava is a key source of food in sub-Saharan Africa and South America, but it contains cyanogenic glucosides and is highly toxic if eaten in unprocessed form. However, some insects and mites can thrive on cyanogenic plants, often to the extent of becoming pests on these plants. Certain moths, such as burnet moths, have gone further and now depend on cyanogenic glucosides for their own defenses against predators such as birds. How these mites and insects are capable of fending off cyanide toxicity has long remained a mystery. Now Wybouw et al. have identified a mite enzyme that detoxifies hydrogen cyanide to produce a compound called beta-cyanoalanine. Remarkably, the DNA that encodes this enzyme did not evolve in animals but originally belonged to a bacterium. Wybouw et al. show that the gene was transferred to the genome of the spider mite Tetranychus urticae perhaps a few hundred million years ago. An equivalent gene was also found in moths and butterflies, which explains why these insects can thrive on plants that produce hydrogen cyanide. This lateral gene transfer from bacteria to animals is a remarkable coalition of two kingdoms against another, and illustrates a new aspect of the chemical warfare between plants and animals. This study also increases our awareness of the importance of laterally transferred genes in the genomes of higher organisms. DOI: http://dx.doi.org/10.7554/eLife.02365.002

International audience; The influence of human activities on soil arthropods of vertisols was assessed in several plots characterized by different land uses in the south-eastern part of Martinique (French West Indies). Abundance acid diversity of soil invertebrate groups and collembolan species were measured in a 40-year-old secondary forest, a 15-year-old fallow, a 4-year-old fellow, a 4-year-old pasture, a 15-year-old pasture and a 20-year-old market-garden. Agricultural practices modified abundance and species distribution of soil arthropods, compared to forest. Arthropod richness (number of taxa present) decreased from forest to market-garden, according to a gradient of intensification of agricultural use (pesticides, tillage, weed control). In the old pasture, the arthropod diversity was lower in spite of a high carbon content. Species richness of Collembola decreased together with plant diversity and water availability.

International audience; In France, biodiversity in primary school is linked to both the scientific topics and sustainable development. Analyzing France’s official primary school program shows that the expected learnings in this field are primarily cognitive and behavioral. In ministerial guidelines, the affective dimension is minimized, in order to highlight scientific objectivity. However, numerous studies show the significance of affective dimension in learning, especially interacting with the cognitive dimension. This paper is part of a research about these two dimensions of biodiversity education learnings in primary school. It relies on the study of arthropods, especially insects. The framework is built on the analysis of scientific and commun sense knowledges, as well as the identification of emotions using a model of emotional maturity. The methodology is based on a quantitative multivariate analysis of survey responses. The experimental protocol has been made from a sample of 285 students aged 8 to 12. They were divided into three groups according to the level of involvement in learnings received about the study of arthropods. Significant differences appear between each group of students, although some correlations between knowledge and emotional maturity have been identified. Specific profiles of learners linking knowledge and emotional dimension have been highlighted in this research.

Bgpi : Equipe 6; Malgré leur rôle primordial dans les écosystèmes, les insectes, qui représentent les trois quarts des espèces animales identifiées, sont encore mal connus. Leur relation avec le règne végétal et l’espèce humaine, que ce soit comme compétiteurs au niveau des cultures ou comme auxiliaires, notamment par la pollinisation, revêt pourtant une importance majeure. Pour mieux comprendre les grandes fonctions des insectes, leur fonctionnement individuel et populationnel, leurs interactions avec les composantes de l’écosystème – en particulier les plantes – et plus globalement leur intégration dans les milieux naturels et anthropisés, cet ouvrage propose ainsi la première synthèse en français sur un domaine ayant connu récemment d’importants développements. Il offre une revue complète et actualisée des grands courants de pensée, des approches et des découvertes dans les différents champs disciplinaires : physiologie animale et végétale, éthologie, écologie chimique, biologie évolutive, agronomie, paléoentomologie... Il présente par ailleurs les multiples applications des recherches pour réduire l’impact des insectes ravageurs sur les cultures, tout en limitant l’usage des insecticides. Des questions souvent sujettes à controverse sont revisitées à la lumière des connaissances scientifiques actuelles : plantes transgéniques, impact des changements climatiques sur l’extension des aires de distribution de ravageurs ou de vecteurs... Illustrée de nombreuses figures et photos, cette somme à vocation pédagogique s’adresse aux étudiants, enseignants et chercheurs, mais aussi à tous les lecteurs intéressés par les relations complexes entre le monde des insectes et le règne végétal.

Background Wolbachia are intracellular bacteria known to be facultative reproductive parasites of numerous arthropod hosts. Apart from these reproductive manipulations, recent findings indicate that Wolbachia may also modify the host’s physiology, notably its immune function. In the parasitoid wasp, Asobara tabida, Wolbachia is necessary for oogenesis completion, and aposymbiotic females are unable to produce viable offspring. The absence of egg production is also associated with an increase in programmed cell death in the ovaries of aposymbiotic females, suggesting that a mechanism that ensures the maintenance of Wolbachia in the wasp could also be responsible for this dependence. In order to decipher the general mechanisms underlying host-Wolbachia interactions and the origin of the dependence, we developed transcriptomic approaches to compare gene expression in symbiotic and aposymbiotic individuals. Results As no genetic data were available on A. tabida, we constructed several Expressed Sequence Tags (EST) libraries, and obtained 12,551 unigenes from this species. Gene expression was compared between symbiotic and aposymbiotic ovaries through in silico analysis and in vitro subtraction (SSH). As pleiotropic functions involved in immunity and development could play a major role in the establishment of dependence, the expression of genes involved in oogenesis, programmed cell death (PCD) and immunity (broad sense) was analyzed by quantitative RT-PCR. We showed that Wolbachia might interfere with these numerous biological processes, in particular some related to oxidative stress regulation. We also showed that Wolbachia may interact with immune gene expression to ensure its persistence within the host. Conclusions This study allowed us to constitute the first major dataset of the transcriptome of A. tabida, a species that is a model system for both host/Wolbachia and host/parasitoid interactions. More specifically, our results highlighted that symbiont infection may interfere with numerous pivotal processes at the individual level, suggesting that the impact of Wolbachia should also be investigated beyond reproductive manipulations.

Both sexes of Grapholita molesta, a key pest of stone fruits, are able to detect host-plant volatiles and the sex pheromone emitted by females, and to modify their behaviour accordingly. How olfactory information is processed in the central nervous system is unknown. Intracellular recordings and stainings were used to characterize antennal lobe (AL) neuron responses to single pheromone components, a behaviourally active blend of five peach volatiles and a pear-fruit ester. AL neurons with different response patterns responded to pheromone components and plant volatiles. In males more neurons responded specifically to the main pheromone component than in females, whereas neurons responding to all three pheromone components were more abundant in females. Neurons responding to all three pheromone components often responded also to the tested plant volatiles in both sexes. Responses to all pheromone components were dose dependent in males and females, but dose-response relationships differed between neurons and tested pheromone components. Among the five AL projection neurons identified neuroanatomically in males, no arborizations were observed in the enlarged cumulus (Cu), although all of them responded to pheromone compounds. In one of two stained projection neurons in females, however, the glomerulus, which is thought to be homologous to the Cu, was targeted. The processing of pheromone information by ordinary glomeruli rather than by the macroglomerular complex is thus a striking feature of this species, indicating that pheromone and plant volatile processing are not entirely separate in this tortricid moth AL. However, the absence of recorded pheromone responses in the Cu needs to be confirmed. We thank Jean-Pierre Rospars, Rickard Ignell and two anonymous referees for helpful comments on the manuscript. This study was supported by research grants from INRA (Projet Jeune Equipe and Projet S.P.E.) to S.A., and from the Spanish Ministry of Education and Science (research grant AGL2007-62366/AGR) to J.A. and C.G. N.V. was financed by fellowship no. BES-2005-7605 from the Spanish Ministry of Educations and Science.

International audience; In ecological systems, indirect interactions between plant pathogens and phytophagous arthropods can arise when infestation by a first attacker alters the common host plant so that although a second attacker could be spatially or temporally separated from the first one, the former could be affected. The induction of plant defense reactions leading to the production of secondary metabolites is thought to have an important role since it involves antagonistic and/or synergistic cross-talks that may determine the outcome of such interactions. We carried out experiments under controlled conditions on young rose plants in order to assess the impact of these indirect interactions on life history traits of three pests: the necrotrophic fungus Botrytis cinerea Pers.: Fr. (Helotiales: Sclerotiniaceae), the aphid Rhodobium porosum Sanderson (Hemiptera: Aphididae) and the thrips Frankliniella occidentalis Pergande (Thysanoptera: Thripidae). Our results indicated (i) a bi-directional negative interaction between B. cinerea and R. porosum, which is conveyed by decreased aphid growth rate and reduced fungal lesion area, as well as (ii) an indirect negative effect of B. cinerea on insect behavior. No indirect effect was observed between thrips and aphids. This research highlights several complex interactions that may be involved in structuring herbivore and plant pathogen communities within natural and managed ecosystems

International audience; Endoparasitoid wasps inject venom proteins with their eggs to protect them from the host immune response and ensure successful parasitism. Here, we report identification of intracellular (SOD1) and extracellular (SOD3) Cu,Zn superoxide dismutase transcripts in the venom apparatus of two Leptopilina species, parasitoids of Drosophila. Leptopilina SODs show sequence and structure similarity to human SODs, but phylogenetic analyses indicate that the extracellular SODs are more related to cytoplasmic vertebrate SODs than to extracellular ones, a feature shared by predicted insect extracellular SODs. We demonstrate that L. boulardi SOD3 (LbSOD3) is indeed secreted and active as monomeric glycosylated forms in venom. Our results also evidence quantitative variation in SOD3 venom contents between closely related parasitoid species since sod3 is 100-fold less expressed in L. heterotoma venom apparatus and no protein and SOD activity are detected in its venom. Leptopilina recombinant SOD3s as well as a mammalian SOD in vitro inhibit the Drosophila phenoloxidase activity in a dose-dependent manner, demonstrating that SODs may interfere with the Drosophila melanization process and therefore with production of cytotoxic compounds. Although the recombinant LbSOD3 quantity needed to observe this effect precludes a systemic effect of the wasp venom SOD3, it is still consistent with a local action at oviposition. This work provides the first demonstration that insect extracellular SODs are indeed secreted and active in an insect fluid and can be used as virulence factors to counteract the host immune response, a strategy largely used by bacterial and fungal pathogens but also protozoan parasites during infection

International audience; Background: Invasion of the mosquito salivary glands by Plasmodium is a critical step for malaria transmission. From a SAGE analysis, we previously identified several genes whose expression in salivary glands was regulated coincident with sporozoite invasion of salivary glands. To get insights into the consequences of these salivary gland responses, here we have studied one of the genes, PRS1 (Plasmodium responsive salivary 1), whose expression was upregulated in infected glands, using immunolocalization and functional inactivation approaches. Methodology/Principal Findings: PRS1 belongs to a novel insect superfamily of genes encoding proteins with DM9 repeat motifs of uncharacterized function. We show that PRS1 is induced in response to Plasmodium, not only in the salivary glands but also in the midgut, the other epithelial barrier that Plasmodium has to cross to develop in the mosquito. Furthermore, this induction is observed using either the rodent parasite Plasmodium berghei or the human pathogen Plasmodium falciparum. In the midgut, PRS1 overexpression is associated with a relocalization of the protein at the periphery of invaded cells. We also find that sporozoite invasion of salivary gland cells occurs sequentially and induces intra-cellular modifications that include an increase in PRS1 expression and a relocalization of the corresponding protein into vesicle-like structures. Importantly, PRS1 knockdown during the onset of midgut and salivary gland invasion demonstrates that PRS1 acts as an agonist for the development of both parasite species in the two epithelia, highlighting shared vector/parasite interactions in both tissues. Conclusions/Significance: While providing insights into potential functions of DM9 proteins, our results reveal that PRS1 likely contributes to fundamental interactions between Plasmodium and mosquito epithelia, which do not depend on the specific Anopheles/P. falciparum coevolutionary history.

Among the 1590 terrestrial arthropod species alien to Europe identified in this book, 78 were selected to produce specific factsheets in order to provide more information on their biology, distribution and impact. We included two more species which are alien in Europe, the horse-chestnut leaf miner (Cameraria ohridella) and the African cotton leafworm (Spodoptera littoralis) because of their importance. These 80 species are perhaps not the most important alien invaders, but they are rather representatives of the main taxonomic groups of alien terrestrial arthropods. They were selected so as to represent different pathways of introduction and diverse impacts on ecosystems, economic activities and human and animal health. These species include two myriapods, one spider, one mite, 18 coleopterans, seven dipterans, 23 hemipterans, 10 hymenopterans, one termite, 14 lepidopterans, and three thrips. Each factsheet includes information on the following aspects: Description and biological cycle: A brief description of adults and immature stages is given, whenever possible illustrated by a photograph, to help the reader identify the species. Further information details the general characteristics of the biological cycle in the invaded area, especially the species' potential to reproduce and the hosts it has colonized. Native habitat: The factsheet includes the habitat type where the species is found in its native range. In order to make habitat types comparable among taxa, we adopted the classification of the European Nature Information System (EUNIS) database (http://eunis.eea.europa.eu). The habitat type codes are detailed in Appendix II. When information was available, we included specific habitat requirements which may help understand the potential of the species to establish and spread in Europe. Habitat occupied in invaded range: The different habitats colonized by the alien species are described as for native habitats. Native range: The native distribution of the species is described. For some species, there is very precise information available, but for others, only brief details of a region or even continent can be given. Introduced range: The date of the first record in Europe and the location of this record is given, as well as details of the process of dispersion in the continent when available. A distribution map is supplied for all species. For most of them, presence/ absence data have been obtained only at country level, but for a few species, more detailed maps are given to show the distribution at regional scale. However, the missing occurrence of species from some countries does not always mean that these countries are not colonized, but may rather result from a lack of data for the country concerned. The map also indicates eradication records where relevant. Pathways: We included information on the routes of introduction to Europe, and the potential of the species to disperse within the continent once it has established. Impact and management: This section details the importance of the species' impacts in the colonized habitats. Both ecological and economical impacts are detailed when known. Practical advice where known is given regarding mechanical, chemical and biological control methods. Selected references: Three of the most relevant references to the history of the species' introduction and spread in Europe are given.

International audience; A total of 1590 species of arthropods alien to Europe have already established on the continent, including 226 more or less cosmopolitan species of uncertain origin (cryptogenic). Th ese alien species are dispersed across 33 taxonomic orders, including crustaceans, chilopods, diplopods, pauropods, Symphyla, mites,arachnids, and insects. However, insects largely dominate, accounting for more than 87% of the species, far in excess of mites (6.4%). Th ree of the insect orders, namely Coleoptera, Hemiptera and Hymenoptera,overall account for nearly 65 % of the total. Th e alien fauna seems to be highly diverse with a total of 257 families involved, of which 30 have no native representatives. However, just 11 families contribute more than 30 species, mainly aphids, scales and hymenopteran chalcids. For a number of families, the arrival of alien species has signifi cantly modifi ed the composition of the fauna in Europe. Examples are given. Th e number of new records of aliens per year has increased exponentially since the 16th century, but a signifi cant acceleration was observed since the second half of the 20th century, with an average of 19.6 alien species newly reported per year in Europe between 2000 and 2008. Th is acceleration appears to be mainly related to the arrival of phytophagous species, probably with the plant trade, whereas the contribution of detritivores, parasitoids and predators has decreased. Some taxa have not shown any acceleration in the rate of arrivals. Asia has supplied the largest number of alien arthropods occurring in Europe (26.7 %), followed by North America (21.9%) but large diff erences in the region of origin are apparent between taxa. Once established, most alien species have not spread throughout Europe, at least yet, with 43.6 % of the species only present in one or two countries, and less than 1% present in more than 40 countries.Large diff erences also exist between European countries in the total number of alien arthropods recorded per country. Italy (700 species) and France (690 species), followed by Great Britain (533 species), host many more species than other countries. Th e number of alien species per country is signifi cantly correlated with socioeconomic and demographic variables.

International audience; The inventory of the leaf and seed beetles alien to Europe revealed a total of 25 species of which 14 seed beetles (bruchids) and 11 leaf beetles mostly belonging to the subfamilies Alticinae and Chrysomelinae. At present, aliens account for 9.4% of the total fauna of seed beetles in Europe whereas this percentage is less than 1% for leaf beetles. Whilst seed beetles dominated the introductions in Europe until 1950, there has been an exponential increase in the rate of arrival of leaf beetles since then. New leaf beetles arrived at an average rate of 0.6 species per year during the period 2000 2009. Most alien species originated from Asia but this pattern is mainly due to seed beetles of which a half are of Asian origin whereas leaf beetles predominantly originated from North America (36.4%). Unlike other insect groups, a large number of alien species have colonized most of Europe. All but one species have been introduced accidentally with either the trade of beans or as contaminants of vegetal crops or stowaway. Most aliens presently concentrate in man-made habitats but little affect natural habitats (

International audience; We record 201 alien curculionoids established in Europe, of which 72 originate from outside Europe. Aliens to Europe belong to fi ve families, but four-fi fths of them are from the Curculionidae. Many families and subfamilies, including some species-rich ones, have few representatives among alien curculionoids,whereas some others are over-represented; these latter, Dryophthoridae, Cossoninae and specially Scolytinae,all contain many xylophagous species. The number of new records of alien species increases continuously,with an acceleration during the last decades. Aliens to Europe originate from all parts of the world,but mainly Asia; few alien curculionoids originate from Africa. Italy and France host the largest number of alien to Europe. Th e number of aliens per country decreases eastwards, but is mainly correlated with importations frequency and, secondarily, with climate. All alien curculionoids have been introduced accidentally via international shipping. Wood and seed borers are specially liable to human-mediated dispersal due to their protected habitat. Alien curculionoids mainly attack stems, and half of them are xylophagous. The majority of alien curculionoids live in human-modifi ed habitats, but many species live in forests and other natural or semi-natural habitats. Several species are pests, among which grain feeders as Sitophilus spp. are the most damaging.

We provide a comprehensive overview of those Lepidopteran invasions to Europe that result from increasing globalisation and also review expansion of species within Europe. A total of 97 non-native Lepidoptera species (about 1% of the known fauna), in 20 families and 11 superfamilies have established so far in Europe, of which 30 alone are Pyraloidea. In addition, 88 European species in 25 families have expanded their range within Europe and around 23% of these are of Mediterranean or Balkan origin, invading the north and west. Although a number of these alien species have been in Europe for hundreds of years, 74% have established during the 20th century and arrivals are accelerating, with an average of 1.9 alien Lepidoptera newly established per year between 2000 2007. For 78 aliens with a known area of origin, Asia has contributed 28.9%, Africa (including Macaronesian islands, Canaries, Madeira and Azores) 21.6%, North America 16.5%, Australasia 7.2% and the neotropics just 5.2%. The route for almost all aliens to Europe is via importation of plants or plant products. Most alien Lepidoptera established in Europe are also confined to man-made habitats, with 52.5% occuring in parks and gardens. We highlight four species in particular, Diaphania perspectalis, Cacyreus marshalli, Cameraria ohridella and Paysandisia archon, as the most important current economic threats.

Corresponding author: Jean-Yves Rasplus (rasplus@supagro.inra.fr); International audience

International audience; How information is transformed along synaptic processing stages is critically important to understand the neural basis of behavior in any sensory system. In moths, males rely on sex pheromone to find their mating partner. It is essential for a male to recognize the components present in a pheromone blend, their ratio, and the temporal pattern of the signal. To examine pheromone processing mechanisms at different levels of the olfactory pathway, we performed single-cell recordings of olfactory receptor neurons (ORNs) in the antenna and intracellular recordings of central neurons in the macroglomerular complex (MGC) of the antennal lobe of sexually mature Agrotis ipsilon male moths, using the same pheromone stimuli, stimulation protocol, and response analyses. Detailed characteristics of the ORN and MGC-neuron responses were compared to describe the transformation of the neuronal responses that takes place in the MGC. Although the excitatory period of the response is similar in both neuron populations, the addition of an inhibitory phase following the MGC neuron excitatory phase indicates participation of local interneurons (LN), which remodel the ORN input. Moreover, MGC neurons showed a wider tuning and a higher sensitivity to single pheromone components than ORNs.

International audience; More than 65% (1040 species) of arthropod species alien to Europe are associated with human-made habitats, especially parks and gardens, human settlements and agricultural lands, whereas woodlands are yet colonized by less than 20% of the alien fauna, which still has a negligible representation in the other natural and semi-natural habitats. Large diff erences in habitat affi nity are observed between alien taxonomic groups. Phytophagous species are predominant among aliens, representing 47.2% of species alien to Europe.

Ce document regroupe de nombreuses données sur les crevettes d’eau douce. Après avoir abordé la question de la phylogénie afin de mieux appréhender la place des crustacés au sein du règne animal, l’auteur aborde leur anatomie et leur physiologie. Ainsi, le lecteur trouvera les informations nécessaires à la compréhension du fonctionnement des organes de la vie de relation, de nutrition ou de la reproduction des crevettes. L’auteur explique également comment mettre en place et entretenir un aquarium de crevettes tant au niveau des paramètres techniques importants à maîtriser que concernant le choix et l’accueil des nouveaux arrivants. Une place importante sera consacrée aux pathologies rencontrées chez les espèces maintenues en aquarium. L’auteur traite enfin de la maintenance d’une espèce robuste de crevette qu’est la Neocaridina heteropoda : approche de ses origines, des détails microscopiques de reconnaissance, des caractéristiques physiologiques et de sa place actuelle au sein de l’aquariophilie. Ce document sera à la fois une présentation utile pour l’aquariophile débutant ainsi qu’un outil précieux pour l’amateur aguerri souhaitant parfaire ses connaissances.

International audience; Here we consider 274 alien Coleoptera species belonging to 41 of the 137 beetle families in Europe (Cerambycidae, Curculionidae sensu lato, Chrysomelidae sensu lato and Coccinelidae are treated separately elsewhere).Among the families we consider as having invaded the European fauna, Acanthocnemidae and Ptilodactylidae represent new arrivals. Many species-rich families have surprisingly few aliens, whereas some relatively minor families such as Dermestidae, Nitidulidae and Anobiidae have a relatively high representation of alien species. Since the start of the 19th century, the number of coleopteran aliens introduced into Europe has continued to increase. Alien species colonizing Europe derive from a wide range of geographic regions as well as ecozones, but the most important source area is Asia. The countries with the largest number of alien species established are France, Germany and Italy. The majority have been introduced accidentally via international transport mechanisms. The most important route for importation is stored products and crops, followed by transport of wood, then horticultural and ornamental plants. Most alien species in these families are found within anthropogenic habitats in Europe. Th e introduction of invasive alien beetles in these families has had signifi cant economic impacts, particularly as pests of stored foodstuff s, as well as serious ecological impacts. For example, the buprestid species Agrilus planipennis, recently recorded in Russia,is an important potential economic threat which may also impact the biodiversity associated with ash trees.

Background Recent genomic analyses of arthropod defense mechanisms suggest conservation of key elements underlying responses to pathogens, parasites and stresses. At the center of pathogen-induced immune responses are signaling pathways triggered by the recognition of fungal, bacterial and viral signatures. These pathways result in the production of response molecules, such as antimicrobial peptides and lysozymes, which degrade or destroy invaders. Using the recently sequenced genome of the pea aphid (Acyrthosiphon pisum), we conducted the first extensive annotation of the immune and stress gene repertoire of a hemipterous insect, which is phylogenetically distantly related to previously characterized insects models. Results Strikingly, pea aphids appear to be missing genes present in insect genomes characterized to date and thought critical for recognition, signaling and killing of microbes. In line with results of gene annotation, experimental analyses designed to characterize immune response through the isolation of RNA transcripts and proteins from immune-challenged pea aphids uncovered few immune-related products. Gene expression studies, however, indicated some expression of immune and stress-related genes. Conclusions The absence of genes suspected to be essential for the insect immune response suggests that the traditional view of insect immunity may not be as broadly applicable as once thought. The limitations of the aphid immune system may be representative of a broad range of insects, or may be aphid specific. We suggest that several aspects of the aphid life style, such as their association with microbial symbionts, could facilitate survival without strong immune protection., Genome Biology, 11 (2), ISSN:1474-760X

SUMMARY To find a mating partner, moths rely on pheromone communication. Released in very low amounts, female sex pheromones are used by males to identify and localize females. Depending on the physiological state (i.e. age, reproductive state), the olfactory system of the males of the noctuid moth Agrotis ipsilon is `switched on or off'. To understand the neural basis of this behavioural plasticity, we performed a detailed characterization of the qualitative, quantitative and temporal aspects of pheromone coding in the primary centre of integration of pheromonal information, the macroglomerular complex (MGC) of the antennal lobe. MGC neurons were intracellularly recorded and stained in sexually mature virgin males. When stimulating antennae of males with the three main components of the female pheromone blend, most of the neurons showed a biphasic excitatory–inhibitory response. Although they showed different preferences, 80% of the neurons responded at least to the main pheromone component (Z-7-dodecenyl acetate). Six stained neurons responding to this component had their dendrites in the largest MGC glomerulus. Changes in the stimulus intensity and duration affected the excitatory phase but not the inhibitory phase properties. The stimulus intensity was shown to be encoded in the firing frequency, the number of spikes and the latency of the excitatory phase, whereas the stimulus duration only changed its duration. We conclude that the inhibitory input provided by local interneurons following the excitatory phase might not contribute directly to the encoding of stimulus characteristics. The data presented will serve as a basis for comparison with those of immature and mated males.

International audience; The shrimp Rimicaris exoculata swarms over high-temperature chimneys at Mid-Atlantic Ridge hydrothermal sites, thriving in a mixture of hot vent fluid (350°C) and cold seawater (2°C). It may, therefore, be subjected to a thermal regime that is assumed to be stressful for animals. Evaluating the stress status of species in their natural environment is a key issue for understanding the thermal biology of metazoans. In the case of deep-sea species, attempts to quantify natural levels of stress proteins are obviously impaired by deleterious decompression effects during sampling. Here we quantified the heat shock protein (hsp70) mRNA expression of shrimps sampled at a depth of 2300 m and recovered at their native pressure. These shrimps were not heat-stressed, as witnessed by their very low level of heat-inducible hsp70, while an important response was evidenced after an experimental 30°C exposure. Our data also indicate that R. exoculata was nevertheless attracted by the temperature of fluid emission, and would deal with the harsh thermal conditions through microhabitat selection close to its thermal preferendum (10 to 25°C).

International audience; In moths, the components of the female pheromone blend are detected in the male antennae by pheromone olfactory receptor neurons (Ph-ORNs) expressing narrowly tuned olfactory receptors. Responses to sex pheromones have generally been thought to be independent from the odorant background. However, interactions between pheromone components and plant volatiles have been reported at behavioral and detection levels. To document the mechanisms of such interactions, we analyzed Ph-ORN responses of Spodoptera littoralis to the main pheromone component, Z9E11-14:Ac, in the presence of 4 monoterpenes. To mimic natural contexts in which plant odors and pheromone emanate from different sources, the 2 stimuli were presented with different temporal patterns and from independent sources. Linalool reversibly reduced the firing response to Z9E11-14:Ac and produced an off effect. Geraniol and geranyl and linalyl acetates reduced the responses to Z9E11-14:Ac with a longer time course. Pulses of linalool over prolonged pheromone stimulation resulted in a discontinuous firing activity. Pulses of pheromone were better separated over a background of linalool, compared with odorless air. The data confirm that plant compounds may modulate the intensity and the temporal coding by Ph-ORNs of pheromone information. This modulation might positively affect mate location at high pheromone density especially nearby a pheromone source.

e2610; International audience; Taste and olfaction are each tuned to a unique set of chemicals in the outside world, and their corresponding sensory spaces are mapped in different areas in the brain. This dichotomy matches categories of receptors detecting molecules either in the gaseous or in the liquid phase in terrestrial animals. However, in Drosophila olfactory and gustatory neurons express receptors which belong to the same family of 7-transmembrane domain proteins. Striking overlaps exist in their sequence structure and in their expression pattern, suggesting that there might be some functional commonalities between them. In this work, we tested the assumption that Drosophila olfactory receptor proteins are compatible with taste neurons by ectopically expressing an olfactory receptor (OR22a and OR83b) for which ligands are known. Using electrophysiological recordings, we show that the transformed taste neurons are excited by odor ligands as by their cognate tastants. The wiring of these neurons to the brain seems unchanged and no additional connections to the antennal lobe were detected. The odor ligands detected by the olfactory receptor acquire a new hedonic value, inducing appetitive or aversive behaviors depending on the categories of taste neurons in which they are expressed i.e. sugar- or bitter-sensing cells expressing either Gr5a or Gr66a receptors. Taste neurons expressing ectopic olfactory receptors can sense odors at close range either in the aerial phase or by contact, in a lipophilic phase. The responses of the transformed taste neurons to the odorant are similar to those obtained with tastants. The hedonic value attributed to tastants is directly linked to the taste neurons in which their receptors are expressed.

Background During blood feeding, the mosquito injects saliva into the vertebrate host. This saliva contains bioactive components which may play a role in pathogen transmission and in host-vector relationships by inducing an immune response in the vertebrate host. The evaluation of human immune responses to arthropod bites might also represent a research direction for assessing individual exposure to the bite of a malaria vector. Methods The present study examined the antibody (Ab) IgG response during the season of exposure to Anopheles gambiae bites in young children living in a malaria endemic area. Immunoblots were performed with An. gambiae saliva to detect anti-saliva Ab bands and the evolution of immunogenic bands at the peak of, and following, the transmission period. Results The results showed that anti-Anopheles Ab was directed against a limited number of salivary proteins (175, 115, 72 and 30 kDa bands). Specific IgG responses to mosquito salivary proteins were variable among exposed individuals; nevertheless, two major bands (175 and 72 kDa) were observed in all immune-responder children. Analysis of the intensity of immunogenic bands revealed that IgG levels against the 175 kDa band were significantly higher during the peak period compared to the end period malaria transmission. Conclusion This preliminary work supports the potential of using anti-saliva immune responses as a measure of exposure to Anopheles bites. The use of immunoblots coupled with evaluation of band intensity could be an adequate tool for distinguishing immunogenic salivary proteins as candidate markers of bite exposure. Furthermore, this study may open the way to design new epidemiological tools for evaluating the risk of malaria exposure.