Search

The sudden interruption of recurring larch budmoth (LBM; Zeiraphera diniana or griseana Gn.) outbreaks across the European Alps after 1982 was surprising, because populations had regularly oscillated every 8–9 years for the past 1200 years or more. Although ecophysiological evidence was limited and underlying processes remained uncertain, climate change has been indicated as a possible driver of this disruption. An unexpected, recent return of LBM population peaks in 2017 and 2018 provides insight into this insect’s climate sensitivity. Here, we combine meteorological and dendrochronological data to explore the influence of temperature variation and atmospheric circulation on cyclic LBM outbreaks since the early 1950s. Anomalous cold European winters, associated with a persistent negative phase of the North Atlantic Oscillation, coincide with four consecutive epidemics between 1953 and 1982, and any of three warming-induced mechanisms could explain the system’s failure thereafter: (1) high egg mortality, (2) asynchrony between egg hatch and foliage growth, and (3) upward shifts of outbreak epicentres. In demonstrating that LBM populations continued to oscillate every 8–9 years at sub-outbreak levels, this study emphasizes the relevance of winter temperatures on trophic interactions between insects and their host trees, as well as the importance of separating natural from anthropogenic climate forcing on population behaviour. Electronic supplementary material The online version of this article (10.1007/s00442-019-04585-9) contains supplementary material, which is available to authorized users.

International audience; The number of invasive alien pest and pathogen species affecting ecosystem functioning, human health and economies has increased dramatically over the last decades. Discoveries of invasive pests and pathogens previously unknown to science or with unknown host associations yet damaging on novel hosts highlights the necessity of developing novel tools to predict their appearance in hitherto naive environments. The use of sentinel plant systems is a promising tool to improve the detection of pests and pathogens before introduction and to provide valuable information for the development of preventative measures to minimize economic or environmental impacts. Though sentinel plantings have been established and studied during the last decade, there still remains a great need for guidance on which tools and protocols to put into practice in order to make assessments accurate and reliable. The sampling and diagnostic protocols chosen should enable as much information as possible about potential damaging agents and species identification. Consistency and comparison of results are based on the adoption of common procedures for sampling design and sample processing. In this paper, we suggest harmonized procedures that should be used in sentinel planting surveys for effective sampling and identification of potential pests and pathogens. We also review the benefits and limitations of various diagnostic methods for early detection in sentinel systems, and the feasibility of the results obtained supporting National Plant Protection Organizations in pest and commodity risk analysis.

The European Union (EU) has recently published its first list of invasive alien species (IAS) of EU concern to which current legislation must apply. The list comprises species known to pose great threats to biodiversity and needs to be maintained and updated. Horizon scanning is seen as critical to identify the most threatening potential IAS that do not yet occur in Europe to be subsequently risk assessed for future listing. Accordingly, we present a systematic consensus horizon scanning procedure to derive a ranked list of potential IAS likely to arrive, establish, spread and have an impact on biodiversity in the region over the next decade. The approach is unique in the continental scale examined, the breadth of taxonomic groups and environments considered, and the methods and data sources used. International experts were brought together to address five broad thematic groups of potential IAS. For each thematic group the experts first independently assembled lists of potential IAS not yet established in the EU but potentially threatening biodiversity if introduced. Experts were asked to score the species within their thematic group for their separate likelihoods of i) arrival, ii) establishment, iii) spread, and iv) magnitude of the potential negative impact on biodiversity within the EU. Experts then convened for a 2‐day workshop applying consensus methods to compile a ranked list of potential IAS. From an initial working list of 329 species, a list of 66 species not yet established in the EU that were considered to be very high (8 species), high (40 species) or medium (18 species) risk species was derived. Here, we present these species highlighting the potential negative impacts and the most likely biogeographic regions to be affected by these potential IAS., We identified 66 species, that are currently absent from the EU, which pose a very high, high or medium threat to biodiversity and ecosystems. The species span a range of functional groups, with primary producers being numerically dominant. Escape from confinement is the pathway considered to be the most likely route of introduction for many species, particularly among plants and vertebrates.

The xylophagous cerambycid Anoplophora glabripennis, the Asian long-horned beetle (ALB), is highly polyphagous and can colonize a wide range of broadleaved host trees causing significant economic damage. For this reason, it is considered a quarantine pest in Europe and North America. Although the global spread of ALB has been depicted recently, no comprehensive studies exist on the genetic pattern of populations’ establishment and dynamics at fine-scale (i.e. within invasive outbreaks), before eradication measures are applied. This information may, however, be particularly important for an efficient management and control of invasive pests. Here, we characterized population genetic diversity and patterns of spread of ALB within and among the four outbreaks detected in Switzerland between 2011 and 2015. For this, we genotyped 223 specimens at 15 nuclear microsatellite loci and conducted specific population-based analyses. Our study shows: (1) At least three independent introductions and a, human-mediated, secondary dispersal event leading to the four outbreaks in the country; (2) An overall low intra-population genetic diversity in the viable and several years active invasive populations; (3) A colonization of single trees by homogeneous ALB genotypes; And (4) an establishment of populations several generations prior to its official discovery.

Depuis son premier signalement en 2008 à Weil-am-Rhein en Allemagne, la pyrale du buis Cydalima perspectalis, n’a pas cessé de se propager dans toute l’Europe et notamment en France qu’elle a presque totalement colonisé en 10 ans. Arrivant d’Asie et plus précisément de Chine grâce au commerce ornementale du buis, elle a su user de ses capacités de vol pour se disperser rapidement. Ceci couplé à une multiple introduction en France venant de Chine et des pays voisin, créant des populations dites « tête de pont », et un commerce du buis florissant leur servant de disperseur passif, l’invasion de C. perspectalis est devenu fulgurante. [br/] Cette étude est consacrée à la compréhension des voies d’invasions de la pyrale du buis à travers la variabilité génétique. Des marqueurs microsatellites ont été utilisés pour cela. Les résultats obtenus ont permis d’observer une structuration génétique des populations en France par rapport aux primo-foyers cités dans la littérature reflétant l’invasion de C. perspectalis jusqu’en Région Centre. La présence de plusieurs clusters bien distincts reflète le phénomène d’introduction multiple. Mais aussi, la présence d’admixture entre les différents clusters, ont aussi montré une migration évidente qui lorsqu’elle n’était pas cohérente (effet « Patchwork ») a permis de déterminer le rôle important du commerce du buis dans ce processus d’invasion en servant de transporteur accidentel., Since its first report in 2008 in Weil-am-Rhein in Germany, the box tree moth Cydalima perspectalis, has not stopped spreading throughout Europe and especially in France that it has almost completely colonized in 10 years. Coming from Asia and more precisely from China thanks to the ornamental boxwood trade, it was able to use its flying abilities to spread quickly. This coupled with a multiple introduction into France from China and neighbouring countries, creating so-called « bridgehead » populations, and a flourishing boxwood trade serving as a passive disperser, the invasion of C. perspectalis has become fast. This study is devoted to understanding the invasion pathways of box tree moth through genetic variability. Microsatellite markers were used for this. The obtained results made it possible to observe a genetic structuring of the populations in France compared to the primofoyers cited in the literature reflecting the invasion of C. perspectalis up to the Région Centre. The presence of several distinct clusters reflects the phenomenon of multiple introductions. But also the presence of admixture between the different clusters, also showed an obvious migration which when it was not coherent (Patchwork effect) made it possible to determine the important role of the boxwood trade in this invasion process by serving as accidental transporter.

International audience; While there is a long-history of biological invasions and their ecological impacts have been widely demonstrated across taxa and ecosystems, our knowledge on the temporal dynamic of these impacts remains extremely limited. Using a meta-analytic approach, we investigated how the ecological impacts of non-native brown trout (Salmo trutta), a model species with a 170-year-long and well-documented history of intentional introductions across the globe, vary with time since introduction. We first observed significant negative ecological impacts immediately after the species introduction. Second, we found that the negative ecological impacts decrease with time since introduction and that the average ecological impacts become nonsignificant more than one century after introduction. This pattern was consistent across other ecological contexts (i.e., geographical location, levels of biological organization, and methodological approach). However, overall negative ecological impacts were more pronounced at the individual and population levels and in experimental studies. While the mechanisms leading to this decrease remain to be determined, our results indicate that rapid response of native organisms (e.g. adaptation, but also local extinction) may play an important role in this dynamic. Changes in native species traits and local extinction can have important conservation implications. Therefore, we argue that the decline of the negative ecological impacts over time should not be used as an argument to neglect the negative impacts of biological invasions

Aim To collect and identify the issues that may affect the future global and local management of biological invasions in the next 20 to 50 years and provide guidance for the prioritisation of actions and policies responding to the management challenges of the future. Location Global Methods We used an open online survey to poll specialists and stakeholders from around the world as to their opinion on the three most important future issues both globally and at their respective local working level. Results The 240 respondents identified 629 global issues that we categorised into topics. We summarised the highest rated topics into five broad thematic areas: (1) environmental change, particularly climate change, (2) the spread of species through trade, (3) public awareness, (4) the development of new technologies to enhance management, and (5) the need to strengthen policies. The respondents also identified 596 issues at their respective local working levels. Management, early detection, prevention and funding-related issues all ranked higher than at the global level. Our global audience of practitioners, policy makers and researchers also elicited topics not identified in horizon scanning exercises led by scientists including potential human health impacts, the need for better risk assessments and legislation, the role of human migration and water management. Main conclusions The topic areas identified in this horizon scan provide guidance where future policy priorities for invasive alien species should be set. First, to reduce the magnitude and speed of environmental change and its impacts on biological invasions; second, to restrict the movement of potentially invasive alien species via trade; third, to raise awareness with the general public and empower them to act; and finally, to invest in innovative technologies that can detect and mitigate adverse impacts of introduced species.

Analyse de risque phytosanitaire portant sur la berce du Caucase

Réalisation d'une analyse de risques relative au houblon du Japon et élaboration de recommandations de gestion

Article en open access; International audience; The invasive yellow-legged hornet, Vespa velutina nigrithorax Lepeletier, 1836 (Hymenoptera: Vespidae), is native to Southeast Asia. It was first detected in France (in the southwest) in 2005. It has since expanded throughout Europe and has caused significant harm to honeybee populations. We must better characterize the hornet's flight capacity to understand the species' success and develop improved control strategies. Here, we carried out a study in which we quantified the flight capacities of V. velutina workers using computerized flight mills. We observed that workers were able to spend around 40% of the daily 7-hour flight tests flying. On average, they flew 10km to 30km during each flight test, although there was a large amount of variation. Workers sampled in early summer had lower flight capacities than workers sampled later in the season. Flight capacity decreased as workers aged. However, in the field, workers probably often die before this decrease becomes significant. During each flight test, workers performed several continuous flight phases of variable length that were separated by rest phases. Based on the length of those continuous flight phases and certain key assumptions, we estimated that V. velutina colony foraging radius is at least 700 m (half that in early summer); however, some workers are able to forage much farther. While these laboratory findings remain to be confirmed by field studies, our results can nonetheless help inform V. velutina biology and control efforts.

Article en open access sur le site de l'éditeur; Invasive species are a major threat to biodiversity, likely a direct consequence of increasing globalization. Greece is situated on the crossroad between different continents, and has been invaded by several insect species in the past; nevertheless, a thorough investigation that would reveal and highlight the pathways and origins of insect species invasion has never been attempted. This study aims at filling this knowledge gap by providing a comprehensive review and in-depth analysis of the non-native entomofauna that has ever entered Greece. The role of neighbouring countries is likely significant, as is the unique features exhibited by each family, and these may help determine the progress of introduction (e.g. cryptic species, parthenogenetic reproduction, etc.). The flow of non-native species between Greece and its neighbouring countries over time shows some relationships with the historical course of turmoil in the region, highlighting for the first time a relation that has long been overlooked but nonetheless is of great economic importance.

Although research on human-mediated exchanges of species has substantially intensified during the last centuries, we know surprisingly little about temporal dynamics of alien species accumulations across regions and taxa. Using a novel database of 45,813 first records of 16,926 established alien species, we show that the annual rate of first records worldwide has increased during the last 200 years, with 37% of all first records reported most recently (1970–2014). Inter-continental and inter-taxonomic variation can be largely attributed to the diaspora of European settlers in the nineteenth century and to the acceleration in trade in the twentieth century. For all taxonomic groups, the increase in numbers of alien species does not show any sign of saturation and most taxa even show increases in the rate of first records over time. This highlights that past efforts to mitigate invasions have not been effective enough to keep up with increasing globalization., Alien species of animals and plants can invade new regions of the earth. This study performs a global analysis of temporal dynamics and spatial patterns of alien species introductions over the past 200 years, and reports no saturation in the rate at which these invasion are increasing.

International audience; Pitch canker, caused by the pathogen Fusarium circinatum, is a serious disease of pines, Pinus species. It is a threat to natural and planted pine forests, and to date it has invaded countries across five continents. Pine-feeding insects can play a key role in the epidemiology of the disease, as wounding agents allowing pathogen access or as vectors transmitting the pathogen from infected to healthy trees. We reviewed the role of insects in the epidemiology of pitch canker worldwide and assessed which insects are present in New Zealand that may act as wounding agents or vectors to determine whether pathogen invasion could adversely affect Pinus radiata plantation forests and urban trees. We also evaluated whether cone or seed insects of pines could be introduced as biological control agents of invasive Pinus contorta and how this may affect the impact of a potential F. circinatum invasion. As there are no native pines or other Pinaceae in New Zealand, there are only a few pine insects, mainly accidental introductions. None of the insects recorded on pines in New Zealand is likely to be a vector, suggesting low disease risk. Of six potentially suitable biocontrol candidates, the European pine cone weevil Pissodes validirostris is the most promising regarding host specificity and impact on seed production, but there is uncertainty about its ability to act as a vector of F. circinatum. Our methodology to review and evaluate the vector potential of pine associates can be used as a generic framework to assess the potential impacts of F. circinatum invasion.

International audience; Determining the native geographic range or origin of alien invasive species is crucial to developing invasive species management strategies. However, the necessary historical dimension is often lacking. The origin of the highly invasive horse-chestnut leaf-mining moth Cameraria ohridella has been controversial since the insect was first described in 1986 in Europe. Here, we reveal that herbarium collections across Europe indicate a Balkan origin for C ohridella. We successfully amplified nuclear DNA and mitochondrial DNA barcode fragments from larvae pressed within leaves of herbarium samples collected as early as 1879. These archival sequences confirm an identity of C ohridella and set back its history in Europe by more than a century. The herbarium samples uncovered previously unknown mitochondrial haplotypes and locally undocumented alleles, showing local outbreaks of C ohridella back to at least 1961 and dynamic frequency changes that may be associated with road development. This case history demonstrates that herbaria are greatly underutilized in studies of insect–plant interactions, herbivore biodiversity, and invasive species' origins.

International audience; Effects of recent climate change have already been detected in many species, and, in particular, in insects. The present paper reviews the key impacts of global warming on insect development and dispersal. The effects of climate change appear to be much more complex than a simple linear response to an average increase in temperature. They can differ between seasons and bioclimatic regions. Earlier flight periods, enhanced winter survival and acceleration of development rates are the major insect responses. Differential response of insects and hosts to warming up might also lead to disruption of their phenological synchrony, but adaptive genetic processes are likely to quickly restore this synchrony. In a number of cases, warming results in removing or relocating the barriers that limit present species’ ranges. It is also likely to facilitate the establishment and spread of invasive alien species. Finally, knowledge gaps are identified and future research interests are suggested.

1. The horse-chestnut leaf miner Cameraria ohridella is an invasive moth in Europe and a serious pest of horse-chestnut Aesculus hippocastanum. The moth also occasionally attacks sycamore maple Acer pseudoplatanus, when situated beside infested horse-chestnuts. 2. The main objective of the present study was to provide an overview of the relationship between C. ohridella and A. pseudoplatanus and to determine whether C. ohridella has the potential to shift to this native tree. 3. In the field, females oviposit on different deciduous tree species. Although less frequently attacked than A. hippocastanum, A. pseudoplatanus was clearly preferred for oviposition over 12 other woody species investigated. 4. Surveys in Europe demonstrated that the majority of A. pseudoplatanus trees found beside infested A. hippocastanum had mines of C. ohridella, even though more than 70% of the larvae died within the first two instars. Attack rates and development success greatly varied from site to site. Attack levels on A. pseudoplatanus were not always correlated with those on A. hippocastanum, and mines on A. pseudoplatanus were sometimes observed beside weakly-infested A. hippocastanum. 5. Field observations, experimental exposure of A. pseudoplatanus saplings and rearing trials in a common garden study showed that individual trees may vary in their susceptibility to C. ohridella, whereas there was no evidence that C. ohridella populations vary in their performance on A. pseudoplatanus. 6. To date, there is little evidence that C. ohridella represents a major risk for A. pseudoplatanus.

International audience; 1 Pityogenes chalcographus L. (Coleoptera: Scolytinae) causes damage in European coniferous forests, primarily on Picea abies L. Karst., but is also recorded on other native and exotic Pinaceae species. Estimating the adequacy between adult preference and larval performance of this beetle among its host-range, as well as the influence of plant taxonomic relatedness on these parameters, would provide useful information on the beetle’s ability to shift onto novel hosts. 2 Choice and no-choice assays were conducted under laboratory conditions. Adult preference and larval performance parameters among two native (Pinus sylvestris L. and Picea abies) and three exotic north American [Pinus contorta Dougl., Picea sitchensis (Bong.) Carr. and Pseudotsuga menziesii Mirbel (Franco)] conifer species were measured. 3 Pityogenes chalcographus exhibited a significant positive relationship between preference and performance. Picea abies was both the preferred and the most suitable host species for larval development. The closest relative, P. sitchensis, was the second best choice in terms of preference and performance. Pseudotsuga menziesii occupied an intermediate position for both beetle preference and performance, and Pinus spp. were the least suitable hosts for beetle development. 4 Adult preference and larval performance ranking among hosts provides little support to the plant taxonomic relatedness hypothesis. Taxonomic relatedness could play a role on the diet breadth, although only at a limited scale, within the genus Picea. At higher taxonomic levels, other factors such as bark thickness might be decisive.

International audience; A total of 385 alien insect species established on woody plants in Europe since 1800. Along with globalization, the rate of arrival of new species exponentially increased during the second half of the 20th century to reach an average of 6.7 species per year during the period 2000-2012. This trend mirrors the rapid increase in the import of live woody plants. Very large discrepancies were observed between alien establishments and interceptions at borders. An analysis of the temporal changes in colonization of trees species growing in Europe revealed that since 2000 the recruitment of alien herbivores increased more rapidly on deciduous trees and shrubs, especially of tropical/ subtropical origin such as palms and eucalypts, whereas this recruitment has decreased in Gymnosperms and slowered in fruit trees. Identifying appropriate and effective tools for the prior warning and early detection of alien insect arrivals is urgently needed but extremely challenging because most potential invaders do not cause significant damage in their native range, and even could be yet unknown to Science. A novel method consisting in sentinel plantings in other continents to detect potential invaders is discussed from the results of recent experiments carried out in China.

International audience; The European Alien Species Information Network (EASIN) was launched in 2012 by the European Commission to facilitate the exploration of existing alien species information and to assist the implementation of European policies on biological invasions. At the core of EASIN, there is an inventory of all known alien and cryptogenic species in Europe (the EASIN Catalogue, herein published), which includes relevant information, such as taxonomic classification, pathways of introduction, year and country of first introduction. Spatial records of species occurrence in Europe are stored in the EASIN geo-databases, integrating data from many data providers and the literature. All this information is publicly available through a widget framework, providing easy to use and flexible tools for searching and mapping. The EASIN datasets have been used for pan-European or regional assessments of pathways and gateways of alien invasions, towards the fulfilment of the related targets of the Convention on Biological Diversity and of European policies. Moreover, in support of the new EU Regulation on the prevention and management of the introduction and spread of invasive alien species in Europe, an Early Warning and Rapid Response System is being developed by EASIN.

International audience

Les interactions entre les organismes jouent un rôle important dans l’organisation de la biodiversité. Toutes les espèces s’engagent d‘une manière ou d’une autre dans des interactions interspécifiques. De nombreux caractères évolutifs peuvent être interprétés comme des adaptations aux interactions avec des parasites,compétiteurs,symbiontes,et enfin mutualistes. Un des objectifs majeur de mes recherches a été l’étude des conflits évolutifs liés aux interactions intra et inter spécifiques et leurs conséquences sur le plan sélectif au niveau des gènes,des individus et des espèces, par l’utilisation d’approches appliquées et fondamentales.Je me suis intéressé en particulier aux conflits pour les ressources liés au parasitisme,au mutualisme entre insectes et plantes et aux conflits liés à la sélection de parentèle chez les insectes sociaux. Plus récemment,j’ai travaillé à l’INRA sur la biologie de l’invasion des mineuses et comment les parasitoïdes natifs s’adaptent à l’arrivée de ces envahisseurs. Utilisant principalement les outils issus de la phylogénétique, j'ai contribué à la compréhension de l’histoire évolutive des groupes d’insectes sur lesquels j’ai travaillé, notamment les mineuses de la famille Gracillariidae, leurs parasitoïdes et les guêpes des figuiers pollinistarices (Agaonidae) et parasites (Sycoryctinae). Le mémoire est divisé en chapitres correspondants aux questions principales. Les principaux résultats sont résumésci- ‐après., As an entomologist, my interests range far and wide in Evolutionary Biology, Systematics and Ecology of insects. Much of my research has been centered on molecular phylogenetics and I have seen the development of this field since the early days of manual sequencing in the 90s to the boom of phylogenetic data in the last 10 years. My interest in molecular phylogenies is mainly driven by questions on how some particular ecological, morphological, biogeographical and behavioural traits have evolved. It is the combination of DNA sequence data and ecology (ie. host use, behavior,..) that has allowed me to address interesting questions about the ecology and evolution of a wide range of insects from fig wasps, leaf- ‐mining moths and theirparasitoids, to bumblebees and wild silk moths.[br/] I have made substantial contributions to the fields of systematics, evolutionary ecology, social behaviour and invasion biology and I am keen to build on this progress. It is only now, with the explosion of new high- ‐throughput, second- ‐generation sequencing approaches, that we have the tools necessary to address fundamental questions about the evolutionary ecology of non- ‐model insects. My long- ‐term goal is to establish a research group investigating evolutionary ecology and systematics across a range of insect groups using a variety of approaches, including laboratory experimentation and observation, fieldwork, genetic analyses and modeling.I have divided this report into chapters named after the different periods of my career. I highlight the main results for each period and the path that I have followed over the years to try to understand insect diversity, how it is organized and how it has originated.

The effect of the alien horse-chestnut leaf miner, Cameraria ohridella, on native fauna was studied by comparing the species richness of native leaf miner communities and the abundance of selected native leaf miner species in the presence and absence of horse-chestnut trees infested by C. ohridella, in various environments in Europe. The species richness of native leaf miner communities in Switzerland was lower at sites where C. ohridella was present than at control sites. In Switzerland, France and Bulgaria, several native leaf miner species were significantly less abundant in the vicinity of infested horse-chestnuts. The native species most affected by the presence of the invasive alien species were those occurring early in the year and sharing their parasitoid complex with C. ohridella. These results suggest apparent competition mediated by shared natural enemies because these are the only link between C. ohridella and native leaf miners using other food resources.

This paper describes a decision-support scheme (DSS) for mapping the area where economically important loss is likely to occur (the endangered area). It has been designed by the PRATIQUE project to help pest risk analysts address the numerous risk mapping challenges and decide on the most suitable methods to follow. The introduction to the DSS indicates the time and expertise that is needed, the data requirements and the situations when mapping the endangered areas is most useful. The DSS itself has four stages. In stage 1, the key factors that influence the endangered area are identified, the data are assembled and, where appropriate, maps of the key factors are produced listing any significant assumptions. In stage 2, methods for combining these maps to identify the area of potential establishment and the area at highest risk from pest impacts are described, documenting any assumptions and combination rules utilised. When possible and appropriate, Stage 3 can then be followed to show whether economic loss will occur in the area at highest risk and to identify the endangered area. As required, Stage 4, described elsewhere, provides techniques for producing a dynamic picture of the invasion process using a suite of spread models. To illustrate how the DSS functions, a maize pest, Diabrotica virgifera virgifera, and a freshwater invasive alien plant, Eichhornia crassipes, have been used as examples.

International audience; Pest Risk Analyses (PRAs) are conducted worldwide to decide whether and how exotic plant pests should be regulated to prevent invasion. There is an increasing demand for science-based risk mapping in PRA. Spread plays a key role in determining the potential distribution of pests, but there is no suitable spread modelling tool available for pest risk analysts. Existing models are species specific, biologically and technically complex, and data hungry. Here we present a set of four simple and generic spread models that can be parameterised with limited data. Simulations with these models generate maps of the potential expansion of an invasive species at continental scale. The models have one to three biological parameters. They differ in whether they treat spatial processes implicitly or explicitly, and in whether they consider pest density or pest presence/absence only. The four models represent four complementary perspectives on the process of invasion and, because they have different initial conditions, they can be considered as alternative scenarios. All models take into account habitat distribution and climate. We present an application of each of the four models to the western corn rootworm, Diabrotica virgifera virgifera, using historic data on its spread in Europe. Further tests as proof of concept were conducted with a broad range of taxa (insects, nematodes, plants, and plant pathogens). Pest risk analysts, the intended model users, found the model outputs to be generally credible and useful. The estimation of parameters from data requires insights into population dynamics theory, and this requires guidance. If used appropriately, these generic spread models provide a transparent and objective tool for evaluating the potential spread of pests in PRAs. Further work is needed to validate models, build familiarity in the user community and create a database of species parameters to help realize their potential in PRA practice.

This paper provides reviews of the most commonly used methods to detect plant pests belonging to groups of invasive organisms with high economic relevance, including Coleoptera (bark beetles, flathead borers, leaf beetles, longhorn beetles, weevils), Diptera (cone and seed flies, fruit flies), Homoptera (aphids, leafhoppers and psyllids, whiteflies), Lepidoptera (moths and butterflies), Thysanoptera (thrips), bacteria (potato brown rot Ralstonia solanacearum) and fungi (pitch canker disease Gibberella circinata, brown rot disease Monilinia fructicola). Future perspectives in detection methods are discussed, with particular reference to the considerable increase in the volume, commodity type and origins of trade in plant material from third countries, the introduction of new crops, the continuous expansion of the EU with new border countries being added, and the impact of climate change affecting the geographical boundaries of pests and their vectors., Cet article passe en revue les méthodes les plus utilisées pour détecter les organismes nuisibles aux plantes appartenant à des groupes d'organismes envahissants qui ont une grande importance économique, comme les Coleoptera (scolytes, buprestides foreurs du bois, chrysomèles, longicornes, charançons), Diptera (mouches des cônes, mouches des fruits), Homoptera (pucerons, cicadelles et psylles, aleurodes), Lepidoptera (papillons), Thysanoptera (thrips), bactéries (pourriture brune de la pomme de terre Ralstonia solanacearum), champignons (chancre du pin Gibberella circinata, moniliose Monilinia fructicola). Les perspectives pour les méthodes de détection sont discutées, avec une référence particulière à l'importante augmentation dans les volumes, les types de marchandises et les origines de échanges commerciaux de matériel végétal à partir de pays tiers, l'introduction de nouvelles cultures, l'expansion continue de l'UE avec l'addition de nouveaux pays à ses frontières et l'impact du changement climatique affectant les frontières géographiques des organismes nuisibles et de leurs vecteurs., Oбзop мeтoдoв oбcлeдoвaний для выявлeния кapaнтинныx вpeдныx opгaнизмoв в Eвpoпeйcкoм coюзe B этoй cтaтьe paccмaтpивaютcя нaибoлee чacтo иcпoльзyeмыe мeтoды, пoзвoляющиe выявлять вpeдныe для pacтeний opгaнизмы, пpинaдлeжaщиe к paзличным гpyппaм инвaзивныx opгaнизмoв, имeющиe выcoкyю экoнoмичecкyю знaчимocть, тaкиe кaк жecткoкpылыe (жyки-кopoeды, злaтки, лиcтoeды, ycaчи, дoлгoнocики), двyкpылыe (шишкoвыe ceмeнныe и плoдoвыe мyxи), paвнoкpылыe (тли, цикaдки, лиcтoблoшки и бeлoкpылки), чeшyeкpылыe (бaбoчки), пyзыpeнoгиe (тpипcы), бaктepии (кapтoфeльнaя бypaя гниль Ralstonia solanacearum), гpибы (paк cocны Gibberella circinata, бypaя гниль Monilinia fructicola). Paccмaтpивaютcя пepcпeктивы paзвития мeтoдoв выявлeния, пpи этoм внимaниe зaocтpяeтcя нa знaчитeльнoм yвeличeнии oбъeмoв тopгoвли, нa paзнooбpaзии типoв тoвapoв и иcтoчникoв oтпpaвки pacтитeльныx мaтepиaлoв, пpoиcxoдящиx из тpeтьиx cтpaн, нa зaвoзe нoвыx кyльтyp, нa пpoдoлжaющeмcя pacшиpeнии EC c дoбaвлeниeм нoвыx cтpaн к eгo гpaницaм и нa вoздeйcтвии климaтичecкиx измeнeний, зaтpaгивaющиx гeoгpaфичecкиe гpaницы pacпpocтpaнeния вpeдныx opгaнизмoв и иx пepeнocчикoв.

A total of 177 species of quarantine arthropods in Europe have been analysed for detection methods that are used in surveillance. This paper provides a link to a list where the methods most frequently used, either alone or in combination, are given for each species. Inspection remains the most common method of detection (108 species). Volatile compounds produced by either insects or host plants, or those released from food attractants are used for 85 species, while light trapping accounts for 28 species. Semiochemicals are known for 73 species, but are commercially available for only 43 species., Un ensemble de 177 espèces d’arthropodes de quarantaine en Europe ont été analysés pour identifier les méthodes de détection qui sont utilisées pour leur surveillance. Cet article fournit un lien vers une liste qui donne les méthodes les plus fréquemment utilisées, seules ou en combinaison, pour chaque espèce. L’inspection reste la méthode la plus fréquente de detection (108 espèces). Les composées volatiles produits soit par des insectes, soit par les plantes-hôtes ou libérés par des aliments, sont utilisés pour 85 espèces, alors que les pièges lumineux sont utilisés pour 28 espèces. Les substances semiochimiques sont connues pour 73 espèces, mais ne sont disponibles commercialement que pour 43 espèces.

Classical biological control is often advocated as a tool for managing invasive species. However, accurate evaluations of parasitoid species complexes and assessment of host specificity are impeded by the lack of morphological variation. Here, we study the possibility of host races/species within the eulophid wasp Pediobius saulius, a pupal generalist parasitoid that parasitize the highly invasive horse-chestnut leaf-mining moth Cameraria ohridella. We analysed the population genetic structure, host associations and phylogeographic patterns of P. saulius in Europe using the COI mitochondrial gene. This marker strongly supports a division into at least five highly differentiated parasitoid complexes, within two of which clades with differing degrees of host specialization were found: a Balkan clade that mainly (but not only) attacks C. ohridella and a more generalist European group that attacks many hosts, including C. ohridella. The divergence in COI (up to 7.6%) suggests the existence of cryptic species, although this is neither confirmed by nuclear divergence nor morphology. We do not find evidence of host tracking. The higher parasitism rates observed in the Balkans and the scarcity of the Balkan–Cameraria haplotypes out of the Balkans open the possibility of using these Balkan haplotypes as biological control agents of C. ohridella elsewhere in Europe.

International audience; Most invasive species established in Europe originate from either Asia or North America, but little is currently known about the potential of the Anatolian Peninsula (Asia Minor) and/or the Near East to constitute invasion sources. Mediterranean forests are generally fragile ecosystems that can be threatened by invasive organisms coming from different regions of the Mediterranean Basin, but for which historical data are difficult to gather and the phylogeographic patterns are still poorly understood for most terrestrial organisms. In this study, we characterized the genetic structure of Megastigmus schimitscheki, an invasive seed-feeding insect species originating from the Near East, and elucidated its invasion route in South-eastern France in the mid 1990s. To disentangle the evolutionary history of this introduction, we gathered samples from the main native regions (Taurus Mountains in Turkey, Lebanon and Cyprus) and from the invaded region that we genotyped using five microsatellite markers and for which we sequenced the mitochondrial Cytochrome Oxidase I gene. We applied a set of population genetic statistics and methods, including approximate Bayesian computation. We proposed a detailed phylogeographic pattern for the Near East populations, and we unambiguously showed that the French invasive populations originated from Cyprus, although the available historical data strongly suggested that Turkey could be the most plausible source area. Interestingly, we could show that the introduced populations were founded from an extremely restricted number of individuals that realized a host switch from Cedrus brevifolia to C. atlantica. Evolutionary hypotheses are discussed to account for this unlikely scenario.

International audience

International audience; An assessment of the likelihood and extent of spread is an integral part of a pest risk analysis for quarantine measures. However, few tools - if any - are available to risk assessors to make an assessment of the spread as a dynamic process in space at the continental scale. Within the frame of the EU project PRATIQUE, we explored avenues for spread modelling and link models of spread to maps of host distribution, climate, and potential economic impacts. Five models for spread were considered: (1) logistic temporal increase of the invaded area following a point introduction; (2) radial range expansion at a constant rate following a point introduction; (3) logistic temporal increase of pest density following a blanket introduction of the invasive alien all across the area of potential establishment in Europe; (4) spatio-temporal population growth and dispersal model constructed by combining local logistic population growth of model 3 with propagule dispersal according to a flexible spatial probability model. These models are generic and simple, to enable rapid parameterization with limited data, enabling scenario analyses in the context of rapid appraisals of pest risk. We developed the models considering Europe as the PRA area. Different models enable alternative assumptions and points of view of the risk assessor to be entered into the assessment process. All models consider the fundamental niche of the invasive species, based on climate suitability and presence of hosts. None of the models is considered a priori better than alternatives. The suite of models provides a more complete picture of invasion consequences than any single model would do. Case studies are provided to illustrate the parameterization process and highlight comparative strengths and weaknesses of the five models. A formal test of model performance against invasion data has not yet been conducted here, but is proposed as a valuable objective for future research. We engage with the community of pest risk assessors in Europe to help risk assessors develop familiarity with the new tools and collect user feedback for identifying future development needs.

National audience

International standards for pest risk analysis (PRA) require assessors to define the endangered area: "the part of the PRA area where the presence of the pest will result in economically important loss." In some cases it may be appropriate to use a simple geographical description but maps generally provide a much better method for defining this area. However, mapping the endangered area is very challenging because it needs to be defined by combining maps of the area of potential establishment (based on climatic suitability and the distribution of hosts, habitats, soils, etc) with maps of factors that indicate where economically important loss is likely to occur. This presentation will describe progress made by the EU-funded PRATIQUE project in developing a decision support scheme (DSS) to guide risk assessors when mapping endangered areas highlighting the importance of clearly defining the map combination rules. The DSS shows how MCAS-S (The Multi-Criteria Analysis Shell for Spatial Decision Support) can be used to display, manipulate, and combine map layers. This software does not require GIS skills, and allows risk assessors to combine maps derived from either continuous or categorical variables using simple mathematical equations and risk matrices. The DSS is linked to the computerised EPPO PRA scheme and modules for mapping climatic suitability, quantifying economic impacts and modelling spread. The DSS is illustrated with a case study of the western corn rootworm (Diabrotica virgifera virgifera) in Europe.

Beaucoup d’organismes sont confrontés à un déséquilibre des ressources nutritives, ce ne permettent pas de couvrir les besoins énergétiques nécessaires à une fitness optimale. Parmi les réponses possibles à ce déséquilibre alimentaire, certains consommateurs primaires ont développé la capacité de manipuler les végétaux pour optimiser les apports énergétiques. Chez les lépidoptères mineurs de feuilles, par exemple, certaines espèces maintiennent la zone minée verte durant le jaunissement du reste de la feuille donnant ainsi naissance à un phénotype qualifié « d’île verte ». Chez Phyllonorycter blancardella, la bactérie Wolbachia semble jouer un rôle prépondérant dans l’induction de ce phénomène. Ce stage consiste en l’étude de cette relation intime plante-insecte-endosymbionte, à un niveau macroévolutif. Les objectifs de ce stage sont : 1) de développer un protocole permettant de détecter Wolbachia à partir de quantités très faibles de tissus (larves de microlépidoptères); 2) de tester la validité du « DNA barcoding » comme outil pour identifier, au niveau de l’espèce, différents stades de Gracillaridae et d’évaluer l’étendue de l’association Wolbachia/mineuses de feuilles/île verte, en investiguant la présence de Wolbachia et des îles vertes pour 162 microlépidoptères dont 142 Gracillaridae. L’ADN des 162 échantillons a été extrait, puis un gène mitochondriale (COI) et un gène nucléaire de l’insecte (histone 3) ont été amplifiés puis séquençés et la présence de Wolbachia a été détectée par amplification du gène 16Sw et FbpA. La phylogénie des mineuses a été faite à partir des deux gènes de l’insecte combinés par la méthode de maximum de vraisemblance. La distribution de Wolbachia et du phénotype « île verte » a pu être etudiée sur 134 individus et la corrélation entre les deux caractères a été réalisée sur 106 individus. La mise au point d’une méthode d’extraction d’ADN pour des individus larve et adulte ouvre de nouvelles perspectives en terme de screening intensif à l’echelle intra et interspécifique. De plus, l’efficacité de l’utilisation du barcoding pour identifier les espèces de Gracillariidae a été confirmée. De la variabilité dans la distribution des caractères d’ « île verte » et de « Wolbachia » a pu être observé au niveau intra et interspécifique. La corrélation entre la présence d’îles vertes et de Wolbachia a pu être validée. On peut donc envisager un rôle clé de la bactérie dans le phénotype « île verte » chez plusieurs espèces. Cependant, certains individus forment des îles vertes mais, d’après les tests fiables, ne sont pas infectés par Wolbachia suggérant que d’autres mécanismes doivent être envisagés. Ce stage permet d’ouvrir de nombreuses perspectives dans l’étude des mécanismes de manipulation de la plante hôte et de la relation symbiotique mineuse/Wolbachia qui y est associée., Many organisms have to face unbalanced food source, in term of energy and relative quantity of nutrients, which can be deleterious for the organism’s fitness. Among a wide range of existing strategies, some herbivores have developed the ability to manipulate plants in order to improve their nutritional value. In leaf-minning moths, for example, some species are able to keep the mined area green the plant withdraws nutrients (usually in the autumn), leading to a phenomenon called “green island”. In Phyllonorycter blancardella, the Wolbachia bacterial endosymbiont appears to play an important role in the formation of this phenotype. Here I use a molecular phylogenetic approach to study the macroevolutionary interactions between leaf-mining moths,their host plants (green islands) and their associated Wolbachia. The aims of this study are: 1) to optimize DNA extraction protocol that allows gene amplification for both insect and Wolbachia from small amounts of tissue (such as microlepidoptera larvae); 2) to test the validity of DNA barcoding as a valuable method to identify Gracillariidae species and 3) to evaluate how widespread the Wolbachia/leafminer/green island relation is by screening the presence of green islands and Wolbachia in 162 microlepidoptera including 142 leaf-mining Gracillariidae micromoth. DNA was extracted and one mitochondrial (CO1) and a nuclear gene fragments (histone 3) was amplified. Wolbachia infection was detected by the amplification of the 16Sw and FbpA genes. The phylogeny of leaf-mining moths was inferred from a concatenated matrix using the maximum likelyhood approach. The distribution of both Wolbachia and green islands based on 134 specimens was mapped on the leaf-mining moth phylogeny on which their evolutionary development was optimized, while the correlation between both characters was tested on 106 specimens. The elaboration of a DNA extraction protocol that allows the extraction of Wolbachia DNA from tiny amounts of tissue, such as early larval stages of Gracillariidae micromoths opens the possibility of screening many more species using larvae (without the need to rear the adult moths) and as is the case in the vast majority of Lepidoptera DNA barcoding was confirmed as a valuable identification method for Gracillariidae species, in particular allowing the unambiguous matching of larval stages. Intra and interspecific variability was observed for the distribution of both the green island phenotype and Wolbachia infection. Significant correlation was found between the evolution of both characters, so Wolbachia is likely to have played an important role in the evolution of green island phenotype, not only in P. blancardella but in leaf-mining moths in general and Gracillariidae micromoths in particular. However, according to the high reliability of our PCR assay, some individuals are able to make green islands without being infected by Wolbachia, which means that other mechanisms have to beconsidered. This study opens new perspectives for the understanding of the mechanisms underlying host plant manipulation byendophagous insects and the Wolbachia/leafminer interactions.

International audience; Pine wilt disease, which has killed millions of pines in Asia, was first reported in Europe (Portugal) in 1999. This disease is caused by the pine wood nematode, Bursaphelenchus xylophilus, and vectored by longhorn beetles of the genus Monochamus. Despite strict control and containment measures, the disease has now spread very widely in Portugal and is now present at a few locations in Spain. Predicting and mapping the potential spread of the nematode and the disease across Europe is crucial to the effective management of this pest. Because the invasion in Europe is relatively recent and containment measures have influenced the natural potential spread of the pest, it has not been possible to parameterize a spread model based on European data. At first, an expansion model initially based on the history of invasion of the pine wilt disease in China was applied to Europe. This model combines short distance spread with a stochastic, individual based model to describe the long distance jumps due to human assisted transportation. Separate introductions of the nematode at 200 European ports were simulated under various climate change scenarios. This study illustrates how a spread model can be used to determine the critical points of entry for invasive species, so that surveillance can be targeted more accurately and control measures prioritised.

International audience; There are currently 1590 terrestrial arthropod species identified as alien to Europe. Of these, 513 are predators or parasites. The largest group is the insects (409 species), followed by spiders (47 species), myriapods (34 species) and mites (23 species). The species within these alien groupings are extremely diverse, as highlighted by the large number of families represented (115 families). The majority (66.1%) of alien arthropod predator and parasite species arrived unintentionally, but at least 174 (33.9%) have been introduced intentionally, mainly for biological control purposes. Assessment of the major invasion pathways is difficult due to the lack of comprehensive information but it is likely that the majority of predatory or parasitic alien arthropods arrive through leading-edge dispersal or as contaminants and stowaways. The number of new species arriving in Europe has progressively increased since 1500, with the increase in global trade over the last century accelerating this rate of increase. Only a small number of alien predatory and parasitic arthropods in Europe have been shown to cause either an ecological or economical impact, yet knowledge is severely limited by a paucity of data.

Risk mapping techniques play a critical role in pest risk analysis (PRA), helping to identify areas at greatest risk, justify appropriate measures and communicate risk. However, there is no existing guide to best practice that (a) helps the risk analyst decide whether it is appropriate to expend the time and resources required to undertake the modelling required to develop a risk map, (b) demonstrates the implications of choosing different climatic modelling and mapping methods for pests with differing ecologies and for which there is varying amounts of information on their climatic responses and distribution, (c) describes how to perform each technique and interpret the results and (d) shows how maps of climatic suitability can be linked with other datasets to map endangered areas. This presentation will outline the progress made in tackling these issues by PRATIQUE, a European funded research project that is addressing the major challenges faced by pest risk analysts.

absent

International audience

International audience; This book provides the first comprehensive review of the fauna of alien terrestrial arthropods that have colonized the European continent and its associated islands. Directly ensuing from the DAISIE proiect, this is the result of the joint work of 89 authors from 27 different European countries. The book summarizes present knowledge of the arthropod invasion process, from temporal trends and biogeographic patterns, to pathways and vectors, invaded habitats, and ecological and economical impacts. A total of 1590 species alien to Europe, including crustaceans, myriapods, mites, spiders, and insects, are listed in two volumes and 21 separate chapters that detail the different taxonomic groups. For each species, all key information - feeding regime, date and country of first record in Europe, invaded countries, invaded habitats, plant or animal host - is supplied. More detailed factsheets are provided for the 80 species considered to be most representative of the different pathways of introduction and of the diversity of impacts on ecosystems, economic activities and human and animal health.

International audience; 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.

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