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[hal-05791476] Répartition de la diversité des bryophytes épiphytes selon l'état sanitaire d'arbres de rétention
Le stage s'inscrit dans le cadre du projet ECART ( Efficacité conservatoire des arbres de rétention en contexte de changement climatique) de l'INRAE, portant sur la diversité et la répartition des bryophytes dans les arbres de rétention des forêts de Tronçais et Vierzon (France). L'étude visait à analyser l'influence de la position dans l'arbre, de l'état sanitaire et des conditions microclimatiques sur les espèces bryophytes relevées sur les arbres. Les résultats montrent que la position dans l'arbre a un effet majeur, à la fois sur le microclimat et sur la répartition des espèces.L'état sanitaire intervient également : il affecte l'effet tampon du houppier et donc des variables climatiques.Ces facteurs sont d'autant plus importants à considérer dans un contexte de changement climatique, qui menace la biodiversité des épiphytes.En effet, le dépérissement accéléré des arbres pourrait fragiliser fortement les communautés de bryophytes. Les premières campagnes ont rencontré certaines difficultés, dans la collecte des données et les analyses. Le projet constitue une première base de connaissances en France sur ce sujet, le but final étant d’orienter la gestion forestière afin de préserver la biodiversité des forêts françaises.
ano.nymous@ccsd.cnrs.fr.invalid (Théa Péot) 11 Oct 2026
https://hal.science/hal-05791476v1
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[hal-05791489] Refining the developmental model of the pine processionary moth, Thaumetopoea pityocampa, to better understand the impact of temperature on survival and resultant phenology
Physiological and ecological processes of insect species are strongly influenced by meteorological conditions, particularly temperatures. Therefore, climate change is a prominent driver of their distribution and phenology. The pine processionary moth (PPM), Thaumetopoea pityocampa, is a forest and urban pest which primarily infests pine trees in southern Europe, North Africa and Asia Minor. Additionally, PPM larvae release urticating setae that can trigger health issues in both humans and animals. PPM distribution is moving northwards as a consequence of climate warming in winter. PPM phenology also appears to be disturbed by climate change but making predictions is still challenging due to the development spanning multiple seasons. A mechanistic model previously developed, using daily air temperatures to simulate the PPM development from the eggs to the last larval stage, provided first evidence of the effects of climate change in this species. However, PPM larvae spend a part of their time inside a silk nest whereby microclimatic conditions may affect their developmental rates. Furthermore, PPM eggs generally appear in summer and larvae achieve their development generally in the following spring. This induces exposure to high and/or low temperatures potentially generating a hitherto overlooked mortality. To refine the phenology model, we considered: 1) a combination of observed air and predicted nest temperatures, as well as the larval behaviour (entering or leaving the nest), and 2) temperature-related mortality factors. This model was calibrated on field observations using an innovating performance metric. Our results highlight how temperature-related mortality factors could shape PPM phenology on the field.
ano.nymous@ccsd.cnrs.fr.invalid (Clément Bourgade) 11 Oct 2026
https://hal.science/hal-05791489v1
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[hal-05791467] Effets du dépérissement sur les variations thermiques à l'echelle microclimatique dans des chênaies impactées par le phénomène de piqûres d'insectes
En France, l'apparition de piqûres d'insectes sur chênes sur pied est un phénomène émergent qui demeure mal compris. Le dépérissement, et son impact potentiel sur les conditions locales, sont deux candidats souvent avancés, mais la caractérisation du microclimat reste un défi technique. Ce travail, qui doit compléter une évaluation faunistique des agents de piqûre en cours dans neuf massifs, porte la caractérisation des variations thermiques à micro-échelle par rapport au milieu hors forêt, au dépérissement et à la hauteur dans l'arbre. Hors forêt, des approches multivariées (ACP, PAM, LDA) et statistiques (GAM) ont échoué à identifier des groupes bioclimatiques entre sites car la variabilité interannuelle est apparue comme le principal facteur structurant. Toutefois, des gradients latitudinaux et longitudinaux pour les températures maximales et minimales journalières ont été détectés par modélisation statistique. En forêt, les GAM sur les mêmes métriques synthétiques confirment des effets significatifs liés au dépérissement et à la position verticale dans l'arbre. Conformément à nos hypothèses, la distribution des écarts entre températures en et hors forêt confirme un tampon thermique inversement proportionnel au dépérissement, divergent entre le jour et la nuit. Ces résultats seront à confronter à l'approche faunistique pour rechercher d'éventuelles associations au phénomène de piqûres.
ano.nymous@ccsd.cnrs.fr.invalid (Marie-Salomé Henry) 11 Oct 2026
https://hal.science/hal-05791467v1
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[hal-05791547] Dispositif d'observation de la réponse des écosystèmes forestiers au changement climatique : exemple d'une solution ouverte et connectée utilisée pour apprécier la micrométéorologie à l'échelle de l'entomofaune
La littérature fait largement état des variations microclimatiques importantes auxquelles les insectes sont soumis, souvent bien différentes des mesures réalisées sous abri, et a fortiori en milieu forestier où des gradients intenses sont attendus entre la canopée et le bas des arbres. Pourtant, le constat est clair sur le manque de données à ces échelles, lié aux difficultés non seulement financières mais également techniques que posent la réplication, la standardisation et la collecte d'un grand nombre de points de mesure nécessaires pour apprécier des variations à fine échelle et en trois dimensions. Je présenterai une solution basée sur des éléments modulaires de la gamme Yoctopuce pour tenter de relever (en partie) ce défi. Ni parfaite ni forcément la plus adaptée à toutes les applications car pas livrée clef en main, cette solution est toutefois à l'essai dans le cadre de projets d'instrumentation de la forêt parce qu'elle répond à une série de critères identifiés comme critiques pour déployer des dispositifs d'observation pérennes : transmission à distance et dans les deux sens (collecte et paramétrage), réduction du coût par point de mesure, modularité et réplicabilité, indépendance (librairies ouvertes, sans abonnement, serveurs autohébergés).
ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Laparie) 11 Oct 2026
https://hal.science/hal-05791547v1
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[hal-05791576] The importance of phenotypic heterogeneity in biological invasions
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ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Laparie) 11 Oct 2026
https://hal.science/hal-05791576v1
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[hal-05791554] Insect invasive success: why considering microenvironments matters (and why it isn't easy)
Microenvironmental conditions are critical yet often overlooked in the success of ectothermic insect invasions, particularly for forest insects that encounter highly variable microclimates during the invasion process, from forest habitats to urban or disturbed environments, sometimes only transiently before invading new forests. These fine-scale variations can strongly influence survival during transport and establishment, where most alien propagules are typically filtered out, but they are rarely considered in invasion studies. Technological advances since the emergence of the Internet of Things, alongside miniaturization and cost reductions, now provide new opportunities to monitor and integrate microclimatic data into invasion biology and forest ecology, thanks to easier data collection. This will allow for better predictions of invasion risks and improved understanding of invasive forest pest dynamics. This talk will address the importance of this issue and briefly introduce custom-made solutions currently being deployed in ongoing forest entomology projects.
ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Laparie) 11 Oct 2026
https://hal.science/hal-05791554v1
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[hal-05791501] Dispositif d’observation de la réponse des écosystèmes forestiers au changement climatique : exemple d’une solution ouverte et connectée pour caractériser la micrométéorologie à l’échelle de l’entomofaune.
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Laparie) 11 Oct 2026
https://hal.science/hal-05791501v1
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[hal-05791511] Insect invasive success: why considering microenvironments matters (and why it ain't easy)
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ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Laparie) 11 Oct 2026
https://hal.science/hal-05791511v1
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[hal-05791504] pclim.net, a database and web application to explore larval phenology of the pine processionary moth Thaumetopoea pityocampa across its range since 2015
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Laparie) 11 Oct 2026
https://hal.science/hal-05791504v1
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[hal-05791573] Using biochemical proxies to assess fitness along a range expansion gradient: physiological responses to thermal stress among populations of the Pine Processionary Moth
Theoretical work suggests that organismal performance and fitness can change along range expansions gradients as a result of two opposing — yet non-exclusive — evolutionary mechanisms. On the one hand, positive selection near the advancing range front may concentrate best dispersers and individuals that best tolerate environmental stress in areas near the limit of the species’ preferendum (spatial sorting). On the other hand, the balance between cumulating and purging deleterious mutations may be altered, potentially reducing fitness. The pine processionary moth (Thaumetopoea pityocampa), a native defoliator expanding nothward due to climate change, is an ideal model to investigate these dynamics, supported by well-documented histories across Europe. The LOADEXP ANR project combines population genomics with physiological and phenotypic approaches to compare proxies of fitness along the expansion gradient and test the genetic load hypothesis. Larval colonies from the range core to the range front were exposed to thermal stress. We developed and optimized a set of biochemical assays to quantify energetic metabolites as proxies of physiological condition before stress, at its onset, and during recovery. Samples are analyzed for soluble sugars (glucose and trehalose) and lipid reserves (triglycerides), key components of insect energy metabolism and stress response. Given the low biomass of some individuals and requirement to extract both the polar and apolar fractions from the same samples, protocols were adapted to micro-scale conditions. This included miniaturized enzymatic assays in microplates, optimized sample preparation and evaluation of extraction procedures to maximize recovery while limiting analytical losses. Ongoing assays aim to capture any variation in energy reserves management and stress tolerance across populations along the expansion gradient. The results will provide insights into the physiological consequences of expansion-associated genetic load. Overall, this work and methodological developments are a step towards explicitly integrating biochemical phenotypes into studies of eco-evolutionary dynamics during range expansions.
ano.nymous@ccsd.cnrs.fr.invalid (Pierre Gosseaume) 11 Oct 2026
https://hal.science/hal-05791573v1
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[hal-05791523] Insect invasive success: why considering microenvironments matters (and why it ain't easy)
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Laparie) 11 Oct 2026
https://hal.science/hal-05791523v1
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[hal-04226078] Yoctoget, a fzf wrapper to get data from Yoctopuce VirtualHub for Web. https://forge.inrae.fr/mathieu.laparie/yoctoget
yoctoget is a simple fzf wrapper written in Bash for the YSensor binary from Yoctopuce's command line API (and only that binary, for now) to ease retrieving in batch the data from remote VirtualHub for Web instances. It allows storing URLs to VirtualHub for Web instances already used in the past to quickly select from them upon the next execution. Although not recommended, the user can store their favourite VirtualHub for Web instance password in secret.conf. yoctoget is an unofficial script, unaffiliated to Yoctopuce SARL, and comes with no warranty on your sensors data.
ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Laparie) 03 Oct 2023
https://hal.inrae.fr/hal-04226078v1
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[hal-04233197] pclim.net, a database and web application to explore larval phenology of the pine processionary moth Thaumetopoea pityocampa across its range since 2015. https://pclim.net
PCLIM is an international network of scientists interested in the responses of the pine processionary moth Thaumetopoea pityocampa to climate change, a winter-active insect whose northward expansion is acknowledged as a bioindicator of winter warming. PCLIMdb is a database of their observations on the phenology of the species throughout its range. The database consists in an annual monitoring of caterpillar colonies to score the most advanced larval instars occuring in mid-winter, when temperatures are the lowest and larval moulting is the most unlikely (thereby making the survey less sensitive to small variations in sampling dates). These annual snapshots are being completed since 2015 and allow benchmarking phenological differences among regions and generations over a geographic extent unique for an insect. This database is currently restricted to PCLIM members but will be made publicly available with a DOI when the corresponding data paper is published. The data is replicated at https://entrepot.recherche.data.gouv.fr/, but currently restricted in access to the contributors (until the data paper is published).
ano.nymous@ccsd.cnrs.fr.invalid (Mathieu Laparie) 09 Oct 2023
https://hal.inrae.fr/hal-04233197v1
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[hal-02653040] Permanent genetic resources added to molecular ecology resources database 1 august 2011-30 september 2011
This article documents the addition of 299 microsatellite marker loci and nine pairs of single-nucleotide polymorphism (SNP) EPIC primers to the Molecular Ecology Resources (MER) Database. Loci were developed for the following species: Alosa pseudoharengus, Alosa aestivalis, Aphis spiraecola, Argopecten purpuratus, Coreoleuciscus splendidus, Garra gotyla, Hippodamia convergens, Linnaea borealis,Menippe mercenaria,Menippe adina, Parus major, Pinus densiflora, Portunus trituberculatus, Procontarinia mangiferae, Rhynchophorus ferrugineus, Schizothorax richardsonii, Scophthalmus rhombus, Tetraponera aethiops, Thaumetopoea pityocampa, Tuta absoluta and Ugni molinae. These loci were cross-tested on the following species: Barilius bendelisis, Chiromantes haematocheir, Eriocheir sinensis, Eucalyptus camaldulensis, Eucalyptus cladocalix, Eucalyptus globulus, Garra litaninsis vishwanath, Garra para lissorhynchus, Guindilla trinervis, Hemigrapsus sanguineus, Luma chequen. Guayaba, Myrceugenia colchagu¨ensis, Myrceugenia correifolia, Myrceugenia exsucca, Parasesarma plicatum, Parus major, Portunus pelagicus, Psidium guayaba, Schizothorax richardsonii, Scophthalmus maximus, Tetraponera latifrons, Thaumetopoea bonjeani, Thaumetopoea ispartensis, Thaumetopoea libanotica, Thaumetopoea pinivora, Thaumetopoea pityocampa ena clade, Thaumetopoea solitaria, Thaumetopoea wilkinsoni and Tor putitora. This article also documents the addition of nine EPIC primer pairs for Euphaea decorata, Euphaea formosa, Euphaea ornata and Euphaea yayeyamana.
ano.nymous@ccsd.cnrs.fr.invalid (S.W. A'Hara) 29 May 2020
https://hal.inrae.fr/hal-02653040v1
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[hal-02650797] An extreme case of plant-insect codiversification: figs and fig-pollinating wasps
It is thought that speciation in phytophagous insects is often due to colonization of novel host plants, because radiations of plant and insect lineages are typically asynchronous. Recent phylogenetic comparisons have supported this model of diversification for both insect herbivores and specialized pollinators. An exceptional case where contemporaneous plant-insect diversification might be expected is the obligate mutualism between fig trees (Ficus species, Moraceae) and their pollinating wasps (Agaonidae, Hymenoptera). The ubiquity and ecological significance of this mutualism in tropical and subtropical ecosystems has long intrigued biologists, but the systematic challenge posed by >750 interacting species pairs has hindered progress toward understanding its evolutionary history. In particular, taxon sampling and analytical tools have been insufficient for large-scale cophylogenetic analyses. Here, we sampled nearly 200 interacting pairs of fig and wasp species from across the globe. Two supermatrices were assembled: on an average, wasps had sequences from 77% of 6 genes (5.6 kb), figs had sequences from 60% of 5 genes (5.5 kb), and overall 850 new DNA sequences were generated for this study. We also developed a new analytical tool, Jane 2, for event-based phylogenetic reconciliation analysis of very large data sets. Separate Bayesian phylogenetic analyses for figs and fig wasps under relaxed molecular clock assumptions indicate Cretaceous diversification of crown groups and contemporaneous divergence for nearly half of all fig and pollinator lineages. Event-based cophylogenetic analyses further support the codiversification hypothesis. Biogeographic analyses indicate that the present-day distribution of fig and pollinator lineages is consistent with a Eurasian origin and subsequent dispersal, rather than with Gondwanan vicariance. Overall, our findings indicate that the fig-pollinator mutualism represents an extreme case among plant-insect interactions of coordinated dispersal and long-term codiversification.
ano.nymous@ccsd.cnrs.fr.invalid (Astrid Cruaud) 29 May 2020
https://hal.inrae.fr/hal-02650797v1
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[hal-05785171] Intra- and interspecific variations in flight performance of oak-associated Agrilinae (Coleoptera: Buprestidae) using computerised flight mills
Several Agrilinae species (Coleoptera: Buprestidae) are thermophilous forest borers, and some are also major invasive pests. They are expected to be favoured by climate change and the global deterioration of forest health, and expand their range and damage. Flight behaviour and performance of these insects are poorly known despite their critical role in dispersal and their relevance to management. This study aimed to assess intra- and interspecific variability in active flight of several Agrilinae species and effects of sex and mass on this variability. We assessed the flight performance of eleven oak-associated species (nine Agrilus , one Coraebus, one Meliboeus ) plus one herb-associated Agrilus . Computer-monitored flight mills were used to measure flight parameters of 250 beetles. Overall, flight capacities were rather homogeneous among species, with a dominance of poor flyers and only Coraebus undatus showed outstanding performance. Beetles generally performed several short flight bouts within one trial, and only a few individuals sustained long flight. The maximal total distance covered across multiple assays until death ranged from 170 to 16 097 m, with a median between 35 and 966 m (excluding individuals that never flew). Add to this interspecific variability, flight distances varied greatly among individuals, but were not influenced by sex. Preflight body mass had mixed effects depending on the species, presumably related to dispersal patterns. In our experimental conditions, most species had limited average dispersal capacities over multiple flight trials. Overall, long-distance dispersal and colonisation events probably depend on a small proportion of individuals which largely exceeded the median performance.
ano.nymous@ccsd.cnrs.fr.invalid (Elodie Le Souchu) 08 Oct 2026
https://hal.inrae.fr/hal-05785171v1
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[hal-05785172] A retrospective analysis on the effects of climate warming on the pine processionary moth at the southern edge of its range
Ectotherms are largely impacted by extreme climate events, essentially heatwaves. In Tunisia, the pine processionary moth (PPM), Thaumetopoea pityocampa , is a defoliator typically laying eggs in summer. Its geographical range is expanding northwards in Europe while retracting from southern Tunisia where summer temperatures can reach extreme heats. We explored the effects of climate change over the last 30 years on PPM at its southern range edge. We investigated variations of fecundity and causes of egg mortality over time using historical and contemporary collections of egg masses. Due to incomplete historical series, a clustering method was used to group climatically homologous sampling sites and perform allochronic analyses on clusters instead of individual localities. Our results suggest negative effects of summer heat on egg survival, down to 0% hatching rate in one site during a major heatwave. Such high hatching failures resulted partly from high egg sterility and aborted embryos, with little effects of parasitism rate, suggesting heat susceptibility during embryonic development, but our results do not allow distinguishing impeded mating success from failed egg maturation or early embryo death. Decreasing female fecundity was observed in regions where allochronic comparisons were possible, associated with a decrease in parasitism rate, while climatic variability increased. Previous studies have confirmed experimentally the thermal sensitivity of PPM early instars to temperatures observed in the present work, including one population from southern Tunisia. However, further work is required to evaluate the relative importance of warming summers among populations, since the risk of heat stress depends on the phenology of sensitive instars, and populations from the warmest areas may not necessarily be the most vulnerable to climate change if they already evolved phenological heat avoidance. In addition to heat‐induced mortality, the ultimate fitness of heat survivors should also be explored to determine potential carry‐over effects on subsequent life stages.
ano.nymous@ccsd.cnrs.fr.invalid (Asma Bourougaaoui) 08 Oct 2026
https://hal.inrae.fr/hal-05785172v1
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[hal-05785169] Seasonality of forest insects: why diapause matters
Insects have major impacts on forest ecosystems, from herbivory and soil-nutrient cycling to killing trees at a large scale. Forest insects from temperate, tropical, and subtropical regions have evolved strategies to respond to seasonality; for example, by entering diapause, to mitigate adversity and to synchronize lifecycles with favorable periods. Here, we show that distinct functional groups of forest insects; that is, canopy dwellers, trunk-associated species, and soil/litter-inhabiting insects, express a variety of diapause strategies, but do not show systematic differences in diapause strategy depending on functional group. Due to the overall similarities in diapause strategies, we can better estimate the impacts of anthropogenic change on forest insect populations and, consequently, on key ecosystems.
ano.nymous@ccsd.cnrs.fr.invalid (Martin Schebeck) 08 Oct 2026
https://hal.inrae.fr/hal-05785169v1
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[hal-05785168] Global change threatens the biodiversity of cold regions: current knowledge and priorities for further research
Cold regions are among the most pristine areas remaining globally, hosting unique fauna and flora. Historically, these regions have often been refugia from land-use change, resource exploitation and pollution, but climate warming and biological invasions increasingly constitute profound threats. Focusing on terrestrial plant and invertebrate species, we provide an overview of the impacts of climate change and biological invasions on the biodiversity of cold regions, from the individual to the species level, and discuss pervasive challenges to understanding and managing these impacts. In particular, we explore the consequences of climate change and biological invasions in the contexts of individual physiology, population dynamics, and species redistribution. We suggest new research avenues by identifying priorities for future studies on plants and invertebrates of cold regions in the context of concurrent climate change and biological invasion.
ano.nymous@ccsd.cnrs.fr.invalid (David Renault) 08 Oct 2026
https://hal.inrae.fr/hal-05785168v1
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[hal-04175404] Worldwide diversity of endophytic fungi and insects associated with dormant tree twigs
Abstract International trade in plants and climate change are two of the main factors causing damaging tree pests (i.e. fungi and insects) to spread into new areas. To mitigate these risks, a large-scale assessment of tree-associated fungi and insects is needed. We present records of endophytic fungi and insects in twigs of 17 angiosperm and gymnosperm genera, from 51 locations in 32 countries worldwide. Endophytic fungi were characterized by high-throughput sequencing of 352 samples from 145 tree species in 28 countries. Insects were reared from 227 samples of 109 tree species in 18 countries and sorted into taxonomic orders and feeding guilds. Herbivorous insects were grouped into morphospecies and were identified using molecular and morphological approaches. This dataset reveals the diversity of tree-associated taxa, as it contains 12,721 fungal Amplicon Sequence Variants and 208 herbivorous insect morphospecies, sampled across broad geographic and climatic gradients and for many tree species. This dataset will facilitate applied and fundamental studies on the distribution of fungal endophytes and insects in trees.
ano.nymous@ccsd.cnrs.fr.invalid (Iva Franić) 02 Aug 2023
https://hal.inrae.fr/hal-04175404v1
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[hal-04175419] Towards a global sentinel plants research strategy to prevent new introductions of non-native pests and pathogens in forests. The experience of HOMED
The use of sentinel woody plants in experimental plantings, Botanical Gardens and Arboreta has been experimentally validated as a tool for identifying possible unknown future threats prior to their introduction into new countries. Sentinel Plantings were recently established in Italy, France, Switzerland, China and South Africa, using a common experimental design. The plantings included various tree and shrub species of broadleaves and conifers. Two planting types were established, each with different objectives. In-patria plantings using native plants aim to estimate, in absence of any phytosanitary treatments, the associations and infestation rates of native insects susceptible to be exported to other countries with that particular commodity. Ex-patria plantings using non-native plants are relevant to identify native insect species capable of switching to the non-native plant that would otherwise be impossible to predict prior to its introduction. In the frame of the EU project HOMED, we have implemented this concept, widening the use of this tool simultaneously to many different countries and continents
ano.nymous@ccsd.cnrs.fr.invalid (Duccio Migliorini) 06 Sep 2023
https://hal.inrae.fr/hal-04175419v1
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[hal-02907131] Pathologists and entomologists must join forces against forest pest and pathogen invasions
The world’s forests have never been more threatened by invasions of exotic pests and pathogens, whose causes and impacts are reinforced by global change. However, forest entomologists and pathologists have, for too long, worked independently, used different concepts and proposed specific management methods without recognising parallels and synergies between their respective fields. Instead, we advocate increased collaboration between these two scientific communities to improve the long-term health of forests. Our arguments are that the pathways of entry of exotic pests and pathogens are often the same and that insects and fungi often coexist in the same affected trees. Innovative methods for preventing invasions, early detection and identification of non-native species, modelling of their impact and spread and prevention of damage by increasing the resistance of ecosystems can be shared for the management of both pests and diseases. We, therefore, make recommendations to foster this convergence, proposing in particular the development of interdisciplinary research programmes, the development of generic tools or methods for pest and pathogen management and capacity building for the education and training of students, managers, decision-makers and citizens concerned with forest health.
ano.nymous@ccsd.cnrs.fr.invalid (Hervé Jactel) 27 Jul 2020
https://hal.inrae.fr/hal-02907131v1
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[hal-04171563] Climate, host and geography shape insect and fungal communities of trees
Abstract Non-native pests, climate change, and their interactions are likely to alter relationships between trees and tree-associated organisms with consequences for forest health. To understand and predict such changes, factors structuring tree-associated communities need to be determined. Here, we analysed the data consisting of records of insects and fungi collected from dormant twigs from 155 tree species at 51 botanical gardens or arboreta in 32 countries. Generalized dissimilarity models revealed similar relative importance of studied climatic, host-related and geographic factors on differences in tree-associated communities. Mean annual temperature, phylogenetic distance between hosts and geographic distance between locations were the major drivers of dissimilarities. The increasing importance of high temperatures on differences in studied communities indicate that climate change could affect tree-associated organisms directly and indirectly through host range shifts. Insect and fungal communities were more similar between closely related vs. distant hosts suggesting that host range shifts may facilitate the emergence of new pests. Moreover, dissimilarities among tree-associated communities increased with geographic distance indicating that human-mediated transport may serve as a pathway of the introductions of new pests. The results of this study highlight the need to limit the establishment of tree pests and increase the resilience of forest ecosystems to changes in climate.
ano.nymous@ccsd.cnrs.fr.invalid (Iva Franić) 17 May 2024
https://hal.inrae.fr/hal-04171563v1
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[hal-04312043] Moths and butterflies on alien shores: Global biogeography of non‐native Lepidoptera
Abstract Aim Lepidoptera is a highly diverse, predominantly herbivorous insect order, with species transported to outside their native range largely facilitated by the global trade of plants and plant‐based goods. Analogous to island disharmony, we examine invasion disharmony, where species filtering during invasions increases systematic compositional differences between native and non‐native species assemblages, and test whether some families are more successful at establishing in non‐native regions than others. Location Hawaii, North America, Galapagos, Europe, South Africa, South Korea, Japan, Nansei Islands, Ogasawara Islands, Australia, New Zealand. Taxon Lepidoptera. Methods We compared numbers of non‐native, unintentionally introduced Lepidoptera species with the land area of 11 regions worldwide. Differences among native and non‐native assemblages in the distribution of species among families were investigated using ordination analysis. We tested whether invasion disharmony is explained by propagule pressure (proxied by species richness in border interceptions) and if families were associated with specific trade commodities. Results In total, 741 non‐native Lepidoptera species, accounting for 0.47% of the global diversity of lepidopterans, are established in at least one of the 11 regions. Crambidae, Pyralidae, Tineidae and Gracillariidae were particularly successful invaders, whereas the two most species‐rich families, Erebidae and Geometridae, were under‐represented among non‐native Lepidoptera. Much of the variation in species numbers in the native, and less so in the non‐native assemblages could be attributed to land area. Although native assemblages were similar among nearby regions, non‐native assemblages were not, suggesting geography had little effect on invasion disharmony. Comparison of established with intercepted species revealed that macromoth families were generally under‐represented in establishments, whereas several micromoth families were under‐represented in interceptions. This discrepancy may relate to greater detectability of larger species or high propagule pressure via associations with specific invasion pathways. Main conclusions Invasion disharmony in Lepidoptera appears to be driven by processes unrelated to the success of native assemblages. While native assemblages developed through long‐term evolutionary radiation, the composition of non‐native assemblages is driven by differential invasion pathways and traits affecting the establishment of founder populations that vary among families.
ano.nymous@ccsd.cnrs.fr.invalid (Richard Mally) 28 Nov 2023
https://hal.inrae.fr/hal-04312043v1
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[hal-05722416] Comparative phylogeographic histories of two conifer–damaging Hylurgus bark beetles in Eurasia
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ano.nymous@ccsd.cnrs.fr.invalid (Yuan Yuan) 20 Aug 2026
https://hal.inrae.fr/hal-05722416v1
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[hal-05525486] Why so many Hemiptera invasions?
The Hemiptera is the fifth-largest insect order but among non-native insect species is approximately tied with the Coleoptera as the most species-rich insect order (Hemiptera comprise 20% more species than in world fauna). This over-representation may result from high propagule pressure or from high species invasiveness. Here, we assess the reasons for over-representation in this group by analysing geographical, temporal and taxonomic variation in numbers of historical invasions.
ano.nymous@ccsd.cnrs.fr.invalid (Andrew M Liebhold) 24 Feb 2026
https://hal.inrae.fr/hal-05525486v1
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[hal-05678907] Integrating landscape ecology into generic surveillance plans for bark‐ and wood‐boring beetles
International trade poses a growing threat to global biosecurity, with bark‐ and wood‐boring beetles representing a major concern for forest health. Non‐native species are frequently introduced at points of entry, where populations can establish in the surrounding landscape. To improve early detection, generic surveillance programs use traps in these high‐risk areas, collecting a broad spectrum of species. These traps also capture native beetles, providing insights into the potential species pool that could become exotic elsewhere. However, implementing effective landscape‐wide surveillance within reasonable resource limits remains challenging. In this study, we used trapping data of Cerambycidae and Scolytinae from 11 high‐risk areas across Europe and North America to develop practical recommendations for generic surveillance at multiple spatial scales. Specifically, we attempted to address two key questions: (1) how to maximize the single‐trap efficacy depending on the trap surroundings; and (2) how many traps should be used in a landscape‐wide sampling depending on landscape composition. Under budget constraints, we recommend prioritizing trap placement within forest patches and avoiding locations surrounded by roads or buildings. Urban‐dominated landscapes required greater sampling effort (i.e., more traps) than forest‐dominated landscapes. Deploying fewer than four traps per square kilometer might lead to an incomplete representation of the local bark‐ and wood‐boring beetle community, losing about 30%–50% of species. Overall, our findings highlight the importance of incorporating landscape ecology into generic surveillance planning to optimize trap effectiveness within resource limitations.
ano.nymous@ccsd.cnrs.fr.invalid (Davide Nardi) 03 Jul 2026
https://hal.inrae.fr/hal-05678907v1
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[hal-02627829] Are traded forest tree seeds a potential source of nonnative pests?
The international seed trade is considered relatively safe from a phytosanitary point of view and is therefore less regulated than trade in other plants for planting. However, the pests carried by traded seeds are not well known. We assessed insects and fungi in 58 traded seed lots of 11 gymnosperm and angiosperm tree species from North America, Europe, and Asia. Insects were detected by X-raying and molecular methods. The fungal community was characterized using high-throughput sequencing (HTS) and by growing fungi on non-selective agar. About 30% of the seed lots contained insect larvae. Gymnosperms contained mostly hymenopteran (Megastigmus spp.) and dipteran (Cecidomyiidae) larvae, while angiosperms contained lepidopteran (Cydia latiferreana) and coleopteran (Curculio spp.) larvae. HTS indicated the presence of fungi in all seed lots and fungi grew on non-selective agar from 96% of the seed lots. Fungal abundance and diversity were much higher than insect diversity and abundance, especially in angiosperm seeds. Almost 50% of all fungal exact sequence variants (ESVs) found in angiosperms were potential pathogens, in comparison with around 30% of potentially pathogenic ESVs found in gymnosperms. The results of this study indicate that seeds may pose a greater risk of pest introduction than previously believed or accounted for. A rapid risk assessment suggests that only a small number of species identified in this study is of phytosanitary concern. However, more research is needed to enable better risk assessment, especially to increase knowledge about the potential for transmission of fungi to seedlings and the host range and impact of identified species.
ano.nymous@ccsd.cnrs.fr.invalid (Iva Franic) 26 May 2020
https://hal.inrae.fr/hal-02627829v1
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[hal-02799280] Climate Warming and Past and Present Distribution of the Processionary Moths (Thaumetopoea spp.) in Europe, Asia Minor and North Africa
Pine processionary moth, Thaumetopea pityocampa, is a model insect indicator of global warming, the northwards and upwards range expansion of this Mediterranean species being directly associated with the recent warming up. The knowledge about the drivers of moth expansion is synthesized. A first standardized mapping of the northern expansion edge, from Western Europe to Turkey, is presented, then detailed for 20 countries of Europe, Asia Minor and North Africa, including future trends. Additional data about the responses of the other Thaumetopoea species are given. Finally, the chapter points out the importance of the man-mediated introductions in the expansion process.
ano.nymous@ccsd.cnrs.fr.invalid (Alain Roques) 05 Jun 2020
https://hal.inrae.fr/hal-02799280v1
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[hal-05314497] One is a worldwide invader, the other never established in other continents: contrasted phylogeographic patterns of two congeneric Hylurgus conifer bark beetles
In the Western Palaearctic, the congeneric bark beetles Hylurgus ligniperda and Hylurgus micklitzi are developing on pine trees. Although H. ligniperda has a larger native range in Europe, both species often occur in sympatry in the Mediterranean Basin. They share rather similar life histories, thus providing an excellent model for comparative studies on species differentiation and ecological traits. Moreover, along with increasing human activities and international trade, H. ligniperda has invaded all continents, whereas H. micklitzi remains confined to the Mediterranean Basin. Our research utilised COI markers to assess the genetic diversity and structure, alongside the demographic history, of both species and revealed marked differences. H. micklitzi exhibited low genetic diversity and shallow population structures with restricted expansion. In contrast, H. ligniperda displayed a longer and more complex post-glacial evolutionary route with four distinct clades originating from separate glacial refugia, coupled with considerable genetic variability across Europe. Comparative analyses about the two species suggest that species traits, such as larger body size, increased voltinism, broader ecological niches and frequent introduction events may have helped the fast global invasion and spread of H. ligniperda over the past century.
ano.nymous@ccsd.cnrs.fr.invalid (Yuan Yuan) 14 Oct 2025
https://hal.inrae.fr/hal-05314497v1
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[hal-03593152] High frequency and diversity of insects and fungi in traded tree seeds
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Iva Franic) 31 Mar 2022
https://hal.inrae.fr/hal-03593152v1
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[hal-05162545] Insect invasion success depends on taxon and trophic group
The majority of non-native animal species globally are insects, though some insect species are more successful invaders than others. These differences can be attributed, in part, to differences among dominant trophic groups. Previous analyses indicate that insect herbivores are generally over-represented among non-native species while other groups, such as predators, are under-represented. Here we explore how invasion success varies among insect taxa and trophic groups. We quantify over-representation in species grouped by taxon (order or family) and larval trophic group (herbivore, detritivore, predator, parasite, brood carer); over- and under-representation is computed by comparing proportional representation of groups among non-native species in 12 world regions with total numbers in these same groups globally. Although herbivores are generally the most successful group among non-natives, we found their invasion success to vary among their taxonomic groups: herbivores are over-represented among Hemiptera, Diptera, Thysanoptera and Hymenoptera, but under-represented among Lepidoptera and Orthoptera; similar patterns are seen at the family-level within orders. Even after accounting for trophic group, some orders were still over-represented. Within trophic groups, this pattern appeared strongest for herbivores, where predominantly parthenogenetic families belonging to the Hemiptera and Thysanoptera were over-represented in non-native assemblages, while families in the Lepidoptera and Polyneoptera were under-represented. Over time (1850s to 2000s), fractions of non-native species numbers in certain orders and trophic groups have varied, such as among parasites, where a considerable turnover took place from mostly bird-lice (Psocodea) in the 19 th century to parasitic wasps (Hymenoptera) in the 20 th century. It is thus likely that factors other than trophic group, such as associations with invasion pathways (e.g., plants, wood packaging), cause the observed differences in the over-representation of families belonging to different orders.
ano.nymous@ccsd.cnrs.fr.invalid (Richard Mally) 15 Jul 2025
https://hal.inrae.fr/hal-05162545v1
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[hal-02627834] Return of the moth: rethinking the effect of climate on insect outbreaks
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.
ano.nymous@ccsd.cnrs.fr.invalid (Ulf Büntgen) 26 May 2020
https://hal.inrae.fr/hal-02627834v1
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[hal-02624868] Fine-scale invasion genetics of the quarantine pest, Anoplophora glabripennis, reconstructed in single outbreaks
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.
ano.nymous@ccsd.cnrs.fr.invalid (Tetyana Tsykun) 26 May 2020
https://hal.inrae.fr/hal-02624868v1
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[hal-04312064] Fewer non‐native insects in freshwater than in terrestrial habitats across continents
Abstract Aim Biological invasions are a major threat to biodiversity in aquatic and terrestrial habitats. Insects represent an important group of species in freshwater and terrestrial habitats, and they constitute a large proportion of non‐native species. However, while many non‐native insects are known from terrestrial ecosystems, they appear to be less represented in freshwater habitats. Comparisons between freshwater and terrestrial habitats of invader richness relative to native species richness are scarce, which hinders syntheses of invasion processes. Here, we used data from three regions on different continents to determine whether non‐native insects are indeed under‐represented in freshwater compared with terrestrial assemblages. Location Europe, North America, New Zealand. Methods We compiled a comprehensive inventory of native and non‐native insect species established in freshwater and terrestrial habitats of the three study regions. We then contrasted the richness of non‐native and native species among freshwater and terrestrial insects for all insect orders in each region. Using binomial regression, we analysed the proportions of non‐native species in freshwater and terrestrial habitats. Marine insect species were excluded from our analysis, and insects in low‐salinity brackish water were considered as freshwater insects. Results In most insect orders living in freshwater, non‐native species were under‐represented, while they were over‐represented in a number of terrestrial orders. This pattern occurred in purely aquatic orders and in orders with both freshwater and terrestrial species. Overall, the proportion of non‐native species was significantly lower in freshwater than in terrestrial species. Main conclusions Despite the numerical and ecological importance of insects among all non‐native species, non‐native insect species are surprisingly rare in freshwater habitats. This is consistent across the three investigated regions. We review hypotheses concerning species traits and invasion pathways that are most likely to explain these patterns. Our findings contribute to a growing appreciation of drivers and impacts of biological invasions.
ano.nymous@ccsd.cnrs.fr.invalid (Agnieszka Sendek) 04 Jun 2024
https://hal.inrae.fr/hal-04312064v1
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[hal-03366792] Preventing invasions of Asian longhorn beetle and citrus longhorn beetle: are we on the right track?
Two Asian longhorn beetles, Anoplophora glabripennis and Anoplophora chinensis, are among the most serious alien invasive species attacking forest and urban trees, both in North America and Europe. Major efforts have been put into preventing further entry and establishment of the two species as well as promoting their successful eradication. Here, we review these efforts, their progress and outcome, and scientific advancements in monitoring and control methods. The combined international activities and harmonizing legislative changes in detection and eradication methods have proven worthwhile, with more than 45% of eradication programmes successful in the last 12 years. Some countries were able to completely eradicate all populations and others managed to reduce the area affected. Although the costs of the eradication programmes can be very high, the benefits outweigh inaction. Attempts to eradicate A. chinensis have been more challenging in comparison with those targeting A. glabripennis. For both species, efforts are hampered by the ongoing arrival of new beetles, both from their native regions in Asia and from other invaded regions via bridgehead effects. The methods used for eradication have not changed much during the last decade, and host removal is still the method most commonly used. On the other hand, detection methods have diversified during the last decade with advances in semiochemical research and use of detection dogs. The next decade will determine if eradications continue to be successful, particularly in the case of A. chinensis, which has been targeted in some countries for containment instead of eradication. Key Message: • Anoplophora glabripennis and Anoplophora chinensis are invasive wood borers native to Asia • Both species are serious pests in their invaded range, attacking healthy forest and urban trees • We analyse data from 2008–2020, regarding interceptions, establishments and eradications • In Europe and North America more than 45% of eradication programmes were successful • Innovations on management strategies and recent scientific achievements are reviewed
ano.nymous@ccsd.cnrs.fr.invalid (Sofia Branco) 05 Oct 2021
https://hal.inrae.fr/hal-03366792v1
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[hal-05128229] Testing a trapping protocol for generic surveillance of wood-boring beetles in heterogeneous landscapes
Baited traps are a basic component of both specific and generic surveillance programs targeting wood-boring beetles at risk of introduction to new habitats because of global trade. Among the numerous protocols developed over the years for generic surveillance of longhorn beetles, jewel beetles, and bark and ambrosia beetles is the simultaneous use of black multi-funnel traps set up in the understory and green multi-funnel traps set up in the canopy of forested areas surrounding ports and other entry points. These traps are commonly baited with multi-lure blends of pheromones and host volatiles. In this study, we tested this trapping protocol in areas surrounding eight entry points located in Europe and North America to determine: i) the relative performance of black-understory traps and green-canopy traps among the targeted taxa; and ii) whether the dissimilarity among communities of beetles collected by the understory vs. canopy traps was affected by taxon and amount of forest cover in the traps’ surroundings. A total of 96,963 individuals belonging to 358 species of wood-boring beetles were collected, including 21 non-native species. Black-understory multi-funnel traps were generally more efficient than green-canopy multi-funnel traps for detecting longhorn beetles and bark and ambrosia beetles, whereas the opposite trend was observed for jewel beetles. Differences between beetle communities caught in black-understory and green-canopy traps were mainly attributed to differences in species richness in jewel beetles, while both differences in species richness and species turnover contributed to the dissimilarity between communities of longhorn beetles and bark and ambrosia beetle. The difference in the number of jewel beetle species caught by the two trapping methodologies decreased with increasing forest cover, whereas species turnover increased when moving from an urban-dominated to a forest-dominated landscape. Overall, these results suggest that the simultaneous use of both black-understory and green-canopy multi-funnel traps can be considered a very efficient approach for generic surveillance of longhorn beetles, jewel beetles and bark and ambrosia beetles in both urban-dominated and forest-dominated areas surrounding entry points.
ano.nymous@ccsd.cnrs.fr.invalid (Giacomo Santoiemma) 24 Jun 2025
https://hal.inrae.fr/hal-05128229v1
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[hal-05070459] Complex population genetic structure of the bark beetle predator Thanasimus formicarius (L.) (Coleoptera: Cleridae) across its European range
Abstract Thanasimus formicarius (L.) (Coleoptera: Cleridae) is an important bark beetle predator and can reduce bark beetle population densities of some of the most severe forest pests in Europe. We analysed the population genetics and phylogeography of T. formicarius across its European range, using mitochondrial COI data from 187 individuals sampled from 23 locations. Our extensive sampling from the Fennoscandian to the Mediterranean region and from Iberia to the Middle East provides insights into the genetic structure of T. formicarius . We found a high genetic diversity, revealing 119 haplotypes across the sampling range. Two main clades, an Atlantic and a Continental, were identified, suggesting the presence of at least two glacial refugia during the last ice ages. An isolated population was discovered on the island of Corsica, suggesting that a limited number of individuals, probably from mainland France, may have colonized Corsica and a founder effect occurred. These findings increase our understanding of the recent evolutionary history of T. formicarius , which was shaped by Pleistocene events and certain species‐specific life‐history traits.
ano.nymous@ccsd.cnrs.fr.invalid (Eva Papek) 16 May 2025
https://hal.inrae.fr/hal-05070459v1
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[hal-05065278] European forests are under increasing pressure from global change-driven invasions and accelerating epidemics by insects and diseases
<div><p>Rising temperatures attributed to anthropogenic climate change have held a firm grip on European forests for over two decades now and disturbances have increased substantially, mainly from insects and pathogens. Empirical evidence suggests a direct linkage between rising temperatures and increasing damage from native insects. Although the rapid spread of non-native invasive pests and pathogens is mainly driven by globalized trade and lacking tree species adaptation to locally new threats, climate change favors rapid range expansion of some invasive pests. Here, we present some examples of tree-insect-pathogen interactions in native and non-native systems that have experienced climate change-induced severe outbreak dynamics. We document the spread of damaging insects and pathogens into previously climatically unsuitable regions and underscore the severe forest damages such species distribution shifts can cause. Although systematic assessments are still pending, the information provided here by multiple independent empirical evidences is highly valuable for identifying some of the most pressing issues in European forest protection. Our work can guide for-est protection agencies in preparing mitigating strategies for upcoming decades.</p></div>
ano.nymous@ccsd.cnrs.fr.invalid (Henrik Hartmann) 13 May 2025
https://hal.inrae.fr/hal-05065278v1
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[hal-03441511] Invasion disharmony in the global biogeography of native and non‐native beetle species
Aim The concept of "island disharmony" has been widely applied to describe the systematic over- and under-representation of taxa on islands compared to mainland regions. Here, we explore an extension of that concept to biological invasions. We compare biogeographical patterns in native and non-native beetle (Coleoptera) assemblages from around the world to test whether beetle invasions represent a random sample of species or whether some families are more prone to invade than others. Location Global. Methods Numbers of non-native beetle species established in ten regions worldwide were compared with the land area of each region. The distribution of species among families was compared with the distribution among families for all species native to the same region and with the distribution among families for the global pool of all known beetle species. Ordination analysis was used to characterize differences among native and non-native assemblages based upon the distribution of species among families. Results We report a total of 1,967 non-native beetle species across all ten regions, and a classic log-log relationship between numbers of species per region and land area though relationships are generally stronger for native assemblages. Some families (e.g., Dermestidae and Bostrichidae) are over-represented and others (e.g., Carabidae, Scarabaeidae and Buprestidae) are under-represented in non-native assemblages. The distribution of species among families is generally similar among native assemblages with greatest similarities among nearby regions. In contrast, non-native species assemblages are more similar to each other than to native species assemblages. Main conclusions Certain families are over-represented, and others are under-represented in non-native beetle assemblages compared to native assemblages, indicating "invasion disharmony" in the global representation of beetle families. Similarities in composition among non-native assemblages may reflect unobserved associations with invasion pathways and life-history traits that shape invasion success of different insect groups.
ano.nymous@ccsd.cnrs.fr.invalid (Andrew M Liebhold) 22 Nov 2021
https://hal.inrae.fr/hal-03441511v1
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[hal-02627715] Forewarned is forearmed: harmonized approaches for early detection of potentially invasive pests and pathogens in sentinel plantings
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.
ano.nymous@ccsd.cnrs.fr.invalid (Carmen Morales-Rodriguez) 26 May 2020
https://hal.inrae.fr/hal-02627715v1
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[hal-02622945] Deciphering the worldwide invasion of the Asian long-horned beetle: A recurrent invasion process from the native area together with a bridgehead effect
Retracing introduction routes is crucial for understanding the evolutionary processes involved in an invasion, as well as for highlighting the invasion history of a species at the global scale. The Asian long-horned beetle (ALB) Anoplophora glabripennis is a xylophagous pest native to Asia and invasive in North America and Europe. It is responsible for severe losses of urban trees, in both its native and invaded ranges. Based on historical and genetic data, several hypotheses have been formulated concerning its invasion history, including the possibility of multiple introductions from the native zone and secondary dispersal within the invaded areas, but none have been formally tested. In this study, we characterized the genetic structure of ALB in both its native and invaded ranges using microsatellites. In order to test different invasion scenarios, we used an approximate Bayesian "random forest" algorithm together with traditional population genetics approaches. The strong population differentiation observed in the native area was not geographically structured, suggesting complex migration events that were probably human-mediated. Both native and invasive populations had low genetic diversity, but this characteristic did not prevent the success of the ALB invasions. Our results highlight the complexity of invasion pathways for insect pests. Specifically, our findings indicate that invasive species might be repeatedly introduced from their native range, and they emphasize the importance of multiple, human-mediated introductions in successful invasions. Finally, our results demonstrate that invasive species can spread across continents following a bridgehead path, in which an invasive population may have acted as a source for another invasion.
ano.nymous@ccsd.cnrs.fr.invalid (Marion Javal) 26 May 2020
https://hal.inrae.fr/hal-02622945v1
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[hal-01522971] Community genetics in the time of next-generation molecular technologies
Understanding the interactions of co-occurring species within and across trophic levels provides key information needed for understanding the ecological and evolutionary processes that underlie biological diversity. As genetics has only recently been integrated into the study of community-level interactions, the time is right for a critical evaluation of potential new, gene-based approaches to studying communities. Next-generation molecular techniques, used in parallel with field-based observations and manipulative experiments across spatio-temporal gradients, are key to expanding our understanding of community-level processes. Here, we introduce a variety of ‘-omics’ tools, with recent studies of plant–insect herbivores and of ectomycorrhizal systems providing detailed examples of how next-generation approaches can revolutionize our understanding of interspecific interactions. We suggest ways that novel technologies may convert community genetics from a field that relies on correlative inference to one that reveals causal mechanisms of genetic co-variation and adaptations within communities.
ano.nymous@ccsd.cnrs.fr.invalid (Felix Gugerli) 15 May 2017
https://hal.science/hal-01522971v1
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[hal-04171539] Worldwide tests of generic attractants, a promising tool for early detection of non-native cerambycid species
A large proportion of the insects which have invaded new regions and countries are emerging species, being found for the first time outside their native range. Being able to detect such species upon arrival at ports of entry before they establish in non-native countries is an urgent challenge. The deployment of traps baited with broad-spectrum semiochemical lures at ports-of-entry and other high-risk sites could be one such early detection tool. Rapid progress in the identification of semiochemicals for cerambycid beetles during the last 15 years has revealed that aggregation-sex pheromones and sex pheromones are often conserved at global levels for genera, tribes or subfamilies of the Cerambycidae. This possibly allows the development of generic attractants which attract multiple species simultaneously, especially when such pheromones are combined into blends. Here, we present the results of a worldwide field trial programme conducted during 2018–2021, using traps baited with a standardised 8-pheromone blend, usually complemented with plant volatiles. A total of 1308 traps were deployed at 302 sites covering simultaneously or sequentially 13 European countries, 10 Chinese provinces and some regions of the USA, Canada, Australia, Russia (Siberia) and the Caribbean (Martinique). We intended to test the following hypotheses: 1) if a species is regularly trapped in significant numbers by the blend on a continent, it increases the probability that it can be detected when it arrives in other countries/continents and 2) if the blend exerts an effective, generic attraction to multiple species, it is likely that previously unknown and unexpected species can be captured due to the high degree of conservation of pheromone structures within related taxa. A total of 78,321 longhorned beetles were trapped, representing 376 species from eight subfamilies, with 84 species captured in numbers greater than 50 individuals. Captures comprised 60 tribes, with 10 tribes including more than nine species trapped on different continents. Some invasive species were captured in both the native and invaded continents. This demonstrates the potential of multipheromone lures as effective tools for the detection of ‘unexpected’ cerambycid invaders, accidentally translocated outside their native ranges. Adding new pheromones with analogous well-conserved motifs is discussed, as well as the limitations of using such blends, especially for some cerambycid taxa which may be more attracted by the trap colour or other characteristics rather than to the chemical blend.
ano.nymous@ccsd.cnrs.fr.invalid (Alain Roques) 27 Jul 2023
https://hal.inrae.fr/hal-04171539v1
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[hal-04169153] Latitudinal gradient in avian insectivory: complementary effects of climate, habitat and bird diversity
According to the Latitudinal Biotic Interaction Hypothesis (LBIH), the general increase in biodiversity towards lower latitudes can be partially explained by an increase in the intensity of biotic interactions. While LBIH received some support for plant-herbivores interactions, much less is known about how higher trophic levels may contribute to shape biotic interactions across latitudinal gradients. We hypothesized that the diversity of insectivorous birds increases towards lower latitude, leading to higher predation rates on insect herbivores. Location Europe. Taxon Insectivorous birds and pedunculate oaks. Methods We deployed plasticine caterpillars in 138 oak trees in 47 sites along a 19° latitudinal gradient in Europe to quantify bird insectivory through predation attempts. In addition, we used passive acoustic monitoring to (i) characterize the acoustic diversity of surrounding soundscapes; and (ii) infer both taxonomic and functional diversity of insectivorous birds from recordings. Results The functional diversity of insectivorous birds increased towards lower latitude. Bird predation increased with latitude, forest cover and bird acoustic diversity but decreased with mean annual temperature and functional richness of insectivorous birds. Contrary to our predictions, latitudinal clines in bird predation attempts were not directly mediated by changes in insectivorous bird diversity or acoustic diversity, but latitude and habitat still had independent effects on predation attempts. Main conclusions Our study does not fully support the predictions of the LBIH of more biotic interactions southwards and advocates for better accounting for activity and abundance of insectivorous birds when studying the large-scale variation in insect-tree interactions.
ano.nymous@ccsd.cnrs.fr.invalid (Laura Schillé) 24 Jul 2023
https://hal.inrae.fr/hal-04169153v1
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[hal-05774215] Ecologically and economically sustainable level of timber harvesting in boreal forests – defining the safe operating space for forest use
Planetary-level analyses indicate that we are exceeding the ecological limits. However, we need approaches to implement global sustainability frameworks regionally, using natural resources at levels that allow for their regeneration. We present a framework to define limits beyond which ecosystems are threatened to collapse, to answer how much we can extract from ecosystems, and to manage natural resources for both human and ecosystem wellbeing. We exemplify this approach with the heath forest habitat types in Finland, which provide most of the national timber production. We use the IUCN Red List of Habitats to set favourable reference values for volume of deadwood, proportion of old-growth forest cover and proportion of deciduous trees. Through forest growth simulations and management optimization, we found that the proportion of old-growth forest is the most challenging criteria to be reached only by 2100. This would require not only a larger use of extensive forest management practices than hitherto but also to drastically reduce the maximum economic sustainable harvest level from the current 96% to 60%. By combining threat assessments with ecosystem modelling and management planning, this approach can support regional decision makers to make informed decisions to stay within safe limits of use of natural resources.
ano.nymous@ccsd.cnrs.fr.invalid (Mikko Mönkkönen) 01 Oct 2026
https://hal.inrae.fr/hal-05774215v1
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[hal-05069629] Déplacement de la processionnaire du pin, <i>Thaumetopoea pityocampa</i>
[...]
ano.nymous@ccsd.cnrs.fr.invalid (Christelle Robinet) 15 May 2025
https://hal.inrae.fr/hal-05069629v1
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[hal-04236342] Landscape genetics of the protected Spanish Moon Moth in core, buffer, and peripheral areas of the Ordesa y Monte Perdido National Park (Central Pyrenees, Spain)
One of the conservation projects carried out by the Ordesa y Monte Perdido National Park is the monitoring of the protected Spanish Moon Moth, Graellsia isabellae (Saturniidae), in several sites within the actual park, buffer zone, and peripheral area. Here we studied the genetic diversity, geographical structure, and connectivity of this iconic insect in those areas with the aim of producing evidence-based recommendations that might help the National Park staff in their decision-making. For this, we non-lethally sampled 402 adult moths from 17 sites and worked at two geographic scales: Western/Central Pyrenees and the area monitored by the staff of the National Park. The multilocus genotypes obtained for nine nuclear microsatellite markers allowed us to quantify genetic variation, investigate population structure, and calculate recent migration rates. Our results revealed a large-scale (ca. 125 km) west–east cline in allele frequencies that causes low overall genetic differentiation (FST = 0.038) and similar levels of diversity among sites. Habitat connectivity revealed as an important element determining dispersal for G. isabellae, given the patchy distribution of the host plant (Pinus sylvestris) in the study area. Gene flow within and outside the National Park was proved, with a particular site of the buffer zone (Bujaruelo) acting as a source of migrants to other localities within and outside the National Park. This finding underlines the importance of considering buffer zones to preserve genetic diversity within protected areas, and that safeguarding the connectedness of pine patches is key to the conservation of this iconic moth.
ano.nymous@ccsd.cnrs.fr.invalid (Marta Vila) 10 Oct 2023
https://hal.inrae.fr/hal-04236342v1
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[hal-04236323] Intra- and inter-specific comparative transcriptomic approaches to reveal candidate effectors of gall induction in the micromoth Caloptilia cecidophora (Gracillariidae, Lepidoptera)
While gall-inducing insects exert a high level of control over their host development and physiology, the molecular mechanisms underlying these manipulation processes are still poorly understood. One way to address this question is to focus on effectors produced by insects and susceptible to undermine the plant immune system and modulate the cellular processes. To find candidate effectors involved in gall induction, we compared the gene expression in the larvae of the micromoth Caloptilia cecidophora (Lepidoptera, Gracillariidae) that induces galls on Glochidion obovatum (Phyllanthaceae) to the larval transcriptome C. ryukyuensis, a closely related non-gallinducing species both sympatric and growing of host plant of the same genus. Three independent methods were used to analyze the transcriptomic data. First, we isolated genes showing a peak of expression at the initiation of the gall induction (third instar), and 505 genes were significantly upregulated in third instar compared to the second and the fourth instars. Among them 22 were specific in C. cecidophora transcripts and successfully annotated. Secondly, we selected genes with expression patterns matching gall-induction using a principal component analysis and a self-organizing map. Ortholog comparisons revealed 36 genes showing an opposite expression pattern between the two species. Finally, we looked for candidate genes based on literature and compared their expression patterns between the two species and among instars. All together, we obtained a list of 58 genes coding for possible effectors. Preliminary results point toward the production of anti-oxidant enzymes and chitinases and suggest the implication of secreted auxin in gall formation.
ano.nymous@ccsd.cnrs.fr.invalid (Antoine Guiguet) 10 Oct 2023
https://hal.inrae.fr/hal-04236323v1
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[hal-04236357] In search of unknown biodiversity – and their resources
EU has initiated the construction of a Red List for European macro moths, including species from the families clearwings (Sesiidae) and burnets (Zygaenidae). Most species in these two families are day active and particularly good indicators on habitat quality and -continuity. One advantage is that most species are specialized on hostplants found on high quality grasslands of various types. However, especially the clearwings are difficult to detect with classical entomological methods. Likewise, burnets may be difficult to discover in declining and fragmented habitats and sometimes also difficult to distinguish. Older distribution maps show that most these taxa were widespread in the pre-industrial landscape. When looking at recent distribution maps for these species, it becomes evident that both our present knowledge, as well as the actual occurrences unfortunately are considerably more restricted. In addition, within both families there are several complexes of sibling species which are hard to determine in the field by nonexperts. Here we review our knowledge on the pheromones used by both these families and highlight the needs for creating new attractants for several European clearwings and burnets. Monitoring of such key species would effectively facilitate the evaluation, protection, monitoring and upholding of valuable grasslands in Europe. We highlight the use of pheromones in citizen science programs such as the French project SESIF, as a cost-efficient way to increase the knowledge of the present situation of these important indicator species.
ano.nymous@ccsd.cnrs.fr.invalid (Nils Ryrholm) 10 Oct 2023
https://hal.inrae.fr/hal-04236357v1
