Nos publications

Nos publications


HAL : Dernières publications

  • [hal-01602096] Host plant specialization matters in the epidemiology of Wolbachia across phytophagous wasps (Hymenoptera: Torymidae)

    Host plant specialization matters in the epidemiology of Wolbachia across phytophagous wasps (Hymenoptera: Torymidae). 8. International Wolbachia Conference (Thomas Boivin) 03 Jun 2020
  • [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. (Felix Gugerli) 15 May 2017
  • [hal-02663969] Species richness and abundance of native leaf miners are affected by the presence of the invasive horse-chestnut leaf miner

    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. (Christelle Péré) 31 May 2020
  • [hal-02325152] Potential spread of the invasive North American termite, Reticulitermes flavipes, and the impact of climate warming

    [...] (Christelle Suppo) 22 Oct 2019
  • [hal-02668740] Ecological effects of invasive alien insects

    A literature survey identified 403 primary research publications that investigated the ecological effects of invasive alien insects and/or the mechanisms underlying these effects. The majority of these studies were published in the last 8 years and nearly two-thirds were carried out in North America.These publications concerned 72 invasive insect species, of which two ant species, Solenopsis invicta and Linepithema humile, accounted for 18% and 14% of the studies, respectively.Most publications investigated effects on native biodiversity at population or community level. Genetic effects and, to a lesser extent, effects on ecosystem services and processes were rarely explored. We review the effects caused by different insect invaders according to: their ecosystem roles, i.e. herbivores, predators, parasites,parasitoids and pollinators; the level of biological organisation at which they occur; and the direct and indirect mechanisms underlying these effects. The best documented effects occur in invasive ants,Eurasian forest herbivores invasive in North America,and honeybees. Impacts may occur through simple trophic interactions such as herbivory, predation or parasitism. Alien species may also affect native species and communities through more complex mechanisms such as competition for resources,disease transmission, apparent competition, or pollination disruption, among others. Finally, some invasive insects, particularly forest herbivores and ants, are known to affect ecosystem processes through cascading effects. We identify biases and gaps in our knowledge of ecological effects of invasive insects and suggest further opportunities for research. (Marc Kenis) 31 May 2020
  • [hal-02634224] The invasive Leptoglossus seed bug, a threat for commercial seed crops, but for conifer diversity?

    Among the recent introductions of alien insects in Europe, the polyphagous western conifer seed bug, Leptoglossus occidentalis Heidemann (Heteroptera; Coreidae) can seriously be regarded as a major threat for all the European conifer forests. In the current study combining laboratory and field experimentations, we characterized first bug damage by developing specific damage categories on seeds of different conifer species by the use of X-ray. Secondly, we investigated the impact of the invasive bug on key conifer species used for afforestation in Western and Central Europe. For this purpose, we performed germination tests on predated seeds which revealed that even light damage (consumption of <1/3 of the whole seed content) strongly reduced the germination capability of the seed. We also compared the impact of feeding on the proportion of filled seeds. Second year cones of Pinus sylvestris and Pinus nigra have been enclosed and offered to different life stages (nymphs and adults) and the results showed a significant reduction of filled seeds whatever the life stage. In field, we annually surveyed the bug seed damage for six different conifer species planted in southwestern French seed orchards. Taking into account the economic value of improved seeds in seed orchards, economic impact of bug damage was important although never exceeded 25 %. Two natural or semi-natural alpine pine stands were also surveyed and appeared to be highly affected by the bug (up to 70 % of damaged seeds). Therefore, bug damage could also be considered as a serious threat for seed production in natural stands. (Vincent Lesieur) 27 May 2020
  • [hal-02651055] Human-mediated long-distance jumps of the pine processionary moth in Europe

    Although climate change is currently affecting the distribution of many species, insects are particularly impacted because of their high sensitivity to temperature. The pine processionary moth, Thaumetopoea pityocampa, is a forest insect extending its distribution in response to climate warming. Some pioneer colonies were recently detected far beyond the main range, near Paris and in eastern France. This study tracked the origin and pathways of these pioneer colonies through a combined use of genetic markers, measurement of female flight capabilities, and comparative analyses of the natural enemy complexes. This study also aimed to determine the establishment capability beyond the main range, considering the survival rate during two recent cold periods. The larval survival rate was higher in pioneer colonies (which behave like urban heat islands) than in main range. The flight capacity of females would not have allowed them to come from the main range or the nearest established colonies, and molecular tools further showed that individuals from at least three pioneer colonies were not assigned or similar to individuals at the edge of the main range. Egg parasitoids were absent while pupal parasitoids were present in the pioneer colonies suggesting an introduction at the pupal stage. These approaches provided strong evidence that this species has been accidentally moved near Paris and to eastern France, supporting the hypothesis of human-mediated transportation over natural dispersal. This type of dispersal was unexpected because of risks from urticating hairs and the easy detection of the species. (Christelle Robinet) 29 May 2020
  • [hal-02636439] Identification and genetic diversity of two invasive Pissodes spp. Germar (Coleoptera: Curculionidae) in their introduced range in the southern hemisphere

    During the first half of the twentieth century, two accidental cases of introduction of Pissodes weevils were recorded from the southern hemisphere. The weevils in South Africa were identified as the deodar weevil (Pissodes nemorensis) and those in South America as the small banded pine weevil (Pissodes castaneus). Wide distribution of the two species in their invasive range, general difficulty in identifying some Pissodes spp., and the varying feeding and breeding behaviours of the species in South Africa has necessitated better evidence of species identity and genetic diversity of both species and population structure of the species in South Africa. Barcoding and the Jerry-to-Pat region of the COI gene were investigated. Morphometric data of the South African species was analysed. Our results confirmed the introduction of only one Pissodes species of North American origin to South Africa. However, this species is not P. nemorensis, but an unrecognized species of the P. strobi complex or a hybrid between P. strobi and P. nemorensis. Only P. castaneus, of European origin, was identified from South America. We identified ten mitochondrial DNA haplotypes from South Africa with evidence of moderate genetic structure among geographic populations. Terminal leader and bole-feeding weevils did not differ at the COI locus. A single haplotype was identified from populations of P. castaneus in South America. Results of the present study will have implications on quarantine, research and management of these insect species. (Mesfin Wondafrash) 27 May 2020
  • [hal-02629921] Dynamics of infection with Wolbachia in Hypera postica (Coleoptera: Curculionidae) during invasion and establishment

    The process of loss or gain of parasites during invasion of new lands is not well understood. The alfalfa weevil Hypera postica is an invasive pest of various leguminous crops and consists of three major mitochondrial haplotypes, ‘Western’, ‘Egyptian’ and ‘Eastern’. The Western strain is infected with the endosymbiotic proteobacteria Wolbachia, that cause unidirectional complete reproductive incompatibility, in its native (Europe) and an introduced (the United States) ranges. However, our preliminary screening of a few introduced populations in Northern Kyushu, southwestern Japan, failed to detect Wolbachia from the Western strain. A larger-scale and historical assessment of Wolbachia infection may allow to estimate when and how the bacteria were lost, and current geographical distribution of infection among host haplotypes. In this study, we aim to assess the Wolbachia-infection status of H. postica populations throughout Northern Kyushu, where H. postica invasion to Japan was first found. A total of 228 individuals from seven regions in Northern Kyushu collected in different time periods from 1982 to 2015 and 14 individuals from Europe were subjected to PCR diagnostics for Wolbachia. Wolbachia from the Western strain was not detected, irrespective of the time periods and geographic areas in Northern Kyushu. We found ‘Egyptian’-strain H. postica collected most recently from an island off Kyushu harboured a supergroup-B Wolbachia variant. This variant was genetically different from the European Wolbachia variant infecting Western-strain H. postica. The infection was new to the Egyptian haplotype and was estimated to have taken place independently of the loss in the Western strain. (S. Iwase) 27 May 2020
  • [hal-02644307] Applying a spread model to identify the entry points from which the pine wood nematode, the vector of pine wilt disease, would spread most rapidly across Europe

    Pine wilt disease, which can rapidly kill pines, is caused by the pine wood nematode, Bursaphelenchus xylophilus. It is expanding its range in many countries in Asia and measures are being taken at the EU level to prevent its spread from Portugal. Due to the threat to European forests, it is important to prevent additional introductions and target surveillance to the points of entry that pose the greatest risk. In this study, we present a model to identify the European ports from which the nematode can spread most rapidly across Europe. This model describes: (1) the potential spread of the pine wood nematode based on short-distance spread (the active flight of the vector beetles) and long-distance spread (primarily due to human-mediated transportation), and (2) the development of pine wilt disease based on climate suitability and the potential spread of the nematode. Separate introductions at 200 European ports were simulated under various climate change scenarios. We found that the pine wood nematode could invade 19–60% of the study area (30°00 N–72°00 N, 25°00 W–40°00 E) by 2030, with the highest spread from ports located in Eastern and Northern Europe. Based on climate change scenarios, the disease could affect 8–34% of the study area by 2030, with the highest spread from ports located in South-Eastern Europe. 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. (Christelle Robinet) 28 May 2020
  • [hal-02639527] Global compositional variation among native and non-native regional insect assemblages emphasizes the importance of pathways

    Insects are among the world’s most ecologically and economically important invasive species. Here we assemble inventories of native and non-native species from 20 world regions and contrast relative numbers among these species assemblages. Multivariate ordination indicates that the distribution of species among insect orders is completely different between native and non-native assemblages. Some orders, such as the Psocoptera, Dictyoptera, Siphonaptera, Thysanoptera, and Hemiptera, are always over-represented in the non-native compared to native assemblages. Other orders, such as the Plecoptera, Trichoptera, Ephemeroptera, Odonata, Mecoptera and Microcoryphila, are consistently under-represented in non-native assemblages. These patterns most likely arise both as a result of variation among taxa in their association with invasion pathways responsible for transporting species among world regions, as well as variation in life-history traits that affect establishment potential. However, our results indicate that species compositions associated with invasiveness are fundamentally different from compositions related to insularity, indicating that colonization of islands selects for a different group of insect taxa than does selection for successful invaders. Native and non-native assemblage compositions were also related, to a lesser extent, to latitude of the region sampled. Together, these results illustrate the dominant role of invasion pathways in shaping the composition of non-native insect assemblages. They also emphasize the difference between natural background colonization of islands and anthropogenic colonization events, and imply that biological invasions are not a simple subset of a long-standing ecological process. (Andrew M. Liebhold) 28 May 2020
  • [hal-02638940] Did the parasitoid Pnigalio mediterraneus (Hymenoptera: Eulophidae) track the invasion of the horse chestnut leafminer?

    How communities of natural enemies, such as parasitoids, adapt to the range expansion of their hosts or the arrival of a novel invasive host is an important question in invasion biology. Do parasitoids track the expansion of their hosts from their shared native range? Do they locally adapt both behaviorally and physiologically to the arrival of a novel species by shifting hosts? Few studies have addressed those questions, yet they are important to develop efficient methods to manage invasive species. Here we focus on Pnigalio mediterraneus Ferriére and Delucchi (Hymenoptera: Eulophidae), an important parasitoid of two major agricultural and ornamental pests, the olive fruit fly Bactrocera oleae Rossi (Diptera: Tephritidae) and the horse chestnut leafminer Cameraria ohridella Deschka & Dimic (Lepidoptera: Gracillariidae). C. ohridella recently invaded Europe starting from the Southern Balkans, whereas B. oleae has been associated since the Quaternary with wild olives in the Mediterranean, where it largely spread after the domestication of cultivated olives. We used two markers, the ribosomal spacer ITS2 and the mitochondrial gene COI. Although the ITS2 dataset provided little variation and no phylogeographic signal, analysis of mtDNA of 188 individuals of P. mediterraneus from 54 European localities allowed us to identify 53 haplotypes. Both nucleotide and haplotype diversity were higher for Mediterranean samples, and from samples reared from B. oleae. The statistical parsimony network identified one haplotype as the most frequent, ancestral and mainly associated with C. ohridella. Our findings suggest that P. mediterraneus locally host switched to C. ohridella from other hosts in the Balkans and later tracked the horse chestnut leafminer invasion over Europe. Therefore both host-tracking and ecological sorting could explain the current distribution of P. mediterraneus haplotypes. (Marco Gebiola) 28 May 2020
  • [hal-02639671] Temporal and interspecific variation in rates of spread for insect species invading Europe during the last 200 years

    Globalization is triggering an increase in the establishment of alien insects in Europe, with several species having substantial ecological and economic impacts. We investigated long-term changes in rates of species spread following establishment. We used the total area of countries invaded by 1171 insect species for which the date of first record in Europe is known, to estimate their current range radius (calculated as [invaded area](0.5)/pi). We estimated initial rates of radial spread and compared them among different groups of insects for all years (1800-2014) and for a subset of more recent decades (1950-2014). Accidentally introduced species spread faster than intentionally introduced species. Considering the whole period 1800-2014, spread patterns also differ between feeding guilds, with decreasing spread rates over residence time in herbivores but not in detritivores or parasitic species. These decreases for herbivorous species appeared mainly in those associated with herbaceous plants and crops rather than woody plants. Initial spread rate was significantly greater for species detected after 1990, roughly 3-4 times higher than for species that arrived earlier. We hypothesize that the political changes in Europe following the collapse of the Iron Curtain in 1989, and the further dismantling of customs checkpoints within an enlarged European Union (EU) have facilitated the faster spread of alien insect species. Also, the number of species first recorded in the Eastern Bloc of the politically-divided Europe before 1989 was lower than for the rest of Europe. A detailed analysis of six recent invaders indicated a dominant role of long-distance translocations related to human activities, especially with the plant trade, in determining rates of spread. (Alain Roques) 28 May 2020
  • [hal-02632311] Role of insect vectors in epidemiology and invasion risk of Fusarium circinatum, and risk assessment of biological control of invasive Pinus contorta

    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. (Eckehard G. Brockerhoff) 27 May 2020
  • [hal-02679340] Competition between exotic and native insects for seed resources in trees of a Mediterranean forest ecosystem

    The seeds of both cedar-of-Lebanon (Cedrus libani) and Cyprus cedar (Cedrus brevifolia) are attacked in their natural range by a specialised chalcid, Megastigmus schimitscheki. From 1995 to 1999, seeds were screened for insect damage in the main cedar plantations of southern France, as well as in the stands where cedar is mixed with firs (Abies spp.). X-rays were used to identify chalcid-infested seeds from which the insects were then reared. The surveys revealed the presence of M. schimitscheki in all the stands of Atlas cedar, Cedrus atlantica, planted at Mt Ventoux, southeastern France. The chalcid also infested seeds of an exotic fir, Abies pinsapo, planted in the same area. However, it has not yet reached the cedar plantations in southwestern France, where the seeds are colonised by a related exotic insect, Megastigmus pinsapinis, originating from North Africa. The latter species was common in cedar seeds at Mt Ventoux in the early 1990s but seems to have been supplanted by M. schimitscheki in the invasion zone. A native chalcid species, Megastigmus suspectus, was also shown to have shifted to a slight extent from a native fir, A. alba, onto cedar. The presence of three chalcid species competing for cedar seed resources may result in a substantial decline of the regeneration potential of that tree species. At Mt Ventoux, up to 92.6% of the cedar seeds were attacked, with 86.8% due to M. schimitscheki. The survey also revealed the widespread presence of another North American chalcid, Megastigmus rafni, in the fir stands of southern France. (J.P. Fabre) 31 May 2020
  • [hal-02668657] Temporal and spatial variations in the parasitoid complex of the horse chestnut leafminer during its invasion of Europe

    The enemy release hypothesis posits that the initial success of invasive species depends on the scarcity and poor adaptation of native natural enemies such as predators and parasitoids. As for parasitoids, invading hosts are first attacked at low rates by a species-poor complex of mainly generalist species. Over the years, however, parasitoid richness may increase either because the invading host continuously encounters new parasitoid species during its spread (geographic spread-hypothesis) or because local parasitoids need different periods of time to adapt to the novel host (adjustment-hypothesis). Both scenarios should result in a continuous increase of parasitoid richness over time. In this study, we reconstructed the development of the hymenopteran parasitoid complex of the invasive leafminer Cameraria ohridella (Lepidoptera, Gracillariidae). Our results show that the overall parasitism rate increases as a function of host residence time as well as geographic and climatic factors, altogether reflecting the historic spread of C. ohridella. The same variables also explain the individual parasitism rates of several species in the parasitoid complex, but fail to explain the abundance of others. Evidence supporting the “geographic spread-hypothesis” was found in the parasitism pattern of Cirrospilus talitzkii (Hymenoptera, Eulophidae), while that of Pediobius saulius, another eulophid, indicated an increase of parasitism rates by behavioral, phenological or biological adjustments. Compared to fully integrated host-parasitoid associations, however, parasitism rates of C. ohridella are still very low. In addition, the parasitoid complex lacks specialists, provided that the species determined are valid and not complexes of cryptic (and presumably more specialized) species. Probably, the adjustment of specialist parasitoids requires more than a few decades, particularly to invaders which establish in ecological niches free of native hosts, thus eliminating any possibility of recruitment of pre-adapted parasitoids. (Giselher Grabenweger) 31 May 2020
  • [hal-02636832] Complex patterns of global spread in invasive insects: eco-evolutionary and management consequences

    The advent of simple and affordable tools for molecular identification of novel insect invaders and assessment of population diversity has changed the face of invasion biology in recent years. The widespread application of these tools has brought with it an emerging understanding that patterns in biogeography, introduction history and subsequent movement and spread of many invasive alien insects are far more complex than previously thought. We reviewed the literature and found that for a number of invasive insects, there is strong and growing evidence that multiple introductions, complex global movement, and population admixture in the invaded range are commonplace. Additionally, historical paradigms related to species and strain identities and origins of common invaders are in many cases being challenged. This has major consequences for our understanding of basic biology and ecology of invasive insects and impacts quarantine, management and biocontrol programs. In addition, we found that founder effects rarely limit fitness in invasive insects and may benefit populations (by purging harmful alleles or increasing additive genetic variance). Also, while phenotypic plasticity appears important post-establishment, genetic diversity in invasive insects is often higher than expected and increases over time via multiple introductions. Further, connectivity among disjunct regions of global invasive ranges is generally far higher than expected and is often asymmetric, with some populations contributing disproportionately to global spread. We argue that the role of connectivity in driving the ecology and evolution of introduced species with multiple invasive ranges has been historically underestimated and that such species are often best understood in a global context. (Jeff R. Garnas) 27 May 2020
  • [hal-04175412] The fast invasion of Europe by the box tree moth: an additional example coupling multiple introduction events, bridgehead effects and admixture events

    Identifying the invasion routes of non-native species is crucial to understanding invasions and customizing management strategies. The box tree moth, Cydalima perspectalis , is native to Asia and was recently accidentally introduced into Europe as a result of the ornamental plant trade. Over the last 15 years, it has spread across the continent and has reached the Caucasus and Iran. It is threatening Buxus trees in both urban areas and forests. To investigate the species’ invasion routes, native and invasive box tree moth populations were sampled, and moth’s genetic diversity and structure were compared using microsatellite markers. Our approximate Bayesian computation analyses strongly suggest that invasion pathways were complex. Primary introductions originating from eastern China probably occurred independently twice in Germany and once in the Netherlands. There were also possibly bridgehead effects, where at least three invasive populations may have served as sources for other invasive populations within Europe, with indication of admixture between the two primary invasive populations. The bridgehead populations were likely those in the countries that play a major role in the ornamental plant trade in Europe, notably Germany, the Netherlands, and Italy. All these invasion processes likely facilitated its fast expansion across Europe and illustrate the role played by the ornamental plant trade not only in the moth’s introduction from China but also in the species’ spread across Europe, leading to an invasion with a complex pattern. (Audrey Bras) 02 Aug 2023
  • [tel-04368466] Structure génétique et modélisation de la distribution des populations de deux espèces invasives de Xylosandrus (Scolytinae - Xyleborini) : deux espèces proches aux histoires d’invasion différentes

    Xylosandrus compactus et X. crassiusculus sont deux scolytes originaires d’Asie du Sud-Est et invasifs sur plusieurs continents, dont la biologie et l’écologie atypiques favorisent l’invasion. Une approche pluridisciplinaire a été utilisée au cours de cette thèse afin (i) d’identifier l’origine des populations invasives et leurs routes d’invasion, et (ii) de déterminer les zones dans lesquelles elles pourraient s'étendre et s’établir. Les routes d’invasion ont été retracées à l’aide d’un marqueur mitochondrial et de marqueurs génomiques, et les zones favorables à l’établissement de chaque espèce ont été déterminées à l’aide de modèles de distribution d’espèces (SDM). Malgré leur proximité écologique et phylogénétique, les deux espèces ont une histoire d’invasion différente. Deux lignées ont été identifiées chez X. compactus, l’une originaire d’Inde ou du Vietnam ayant envahi l’Afrique et l’autre originaire de la région de Shanghai et ayant envahi indépendamment les Amériques et les îles du Pacifique, puis l’Europe. X. crassiusculus est composé de deux clusters très divergents, majoritairement allopatriques et possédant des niches écologiques différentes. Le cluster 1 a envahi indépendamment les îles du Pacifique et l’Afrique. Le cluster 2 est responsable de l’invasion en Amérique, en Europe, en Afrique et en Océanie, avec plusieurs invasions indépendantes de multiples origines (dont des événements dits "tête de pont") suivies de dispersion intra-continentale. Les SDM ont montré pour les deux espèces l’existence de zones favorables où elles ne sont pas encore présentes et qui sont donc susceptibles d’être envahies secondairement. Nous anticipons également un impact du changement climatique sur leurs potentielles distributions futures. A l'inverse, l'évolution récente du climat n'est pas responsable de l'invasion récente de l'Europe, ce continent étant favorable depuis plusieurs décennies. (Teddy Urvois) 01 Jan 2024
  • [hal-02608517] Consequences of fluvial maintenance operations on the biodiversity and landscape in the Mareau-aux-Prés islands (National Reserve of Saint-Mesmin, Loire River, France)

    The Mareau-aux-Prés islands, along the Loire river are characterized by a multiple channel pattern, where natural limestone riffles influence the morphology and spatial distribution of vegetated islands and secondary channels. Within these islands, in september 2012, fluvial management operations (FMO) were launched. The vegetation of the central sandy-gravelly bar (3 ha area) was uprooted and the bar level lowered in order to maintain the flow capacity of the river. The FMO are equivalent to a natural important flood : a new bare mineral substrate has appeared and since spring 2013 followed the succession of geomorphic, pioneer and biogeomorphic phases in interactions between hydro-morphodynamics and Salicaceae vegetation.This sandy-gravelly bar is an ideal field support for studying long-term ecological issues. A multi-disciplinary research programme ('BioMareau' project) is currently being conducted from 2012 to 2019, focusing on interactions and feedbacks between biotic and abiotic components and, since 2017, on landscape evolution and perception. (Marc M. Villar) 16 May 2020
  • [hal-02608524] Five years study of consequences of fluvial maintenance operations on the biodiversity in the Mareau-aux-Prés islands (Loire river, France)

    The Mareau-aux-Prés islands, along the Loire river are characterized by a multiple channel pattern, where natural limestone riffles influence the morphology and spatial distribution of vegetated islands, secondary channels and alluvial bars. Within these islands, in september 2012, the vegetation of the central 3 ha sandy-gravelly bar was uprooted and the bar level lowered in order to maintain the flow capacity of the river. A new sandy-gravelly bar appeared in spring 2013, ideal field support for studying long-term ecological issues. A multi-disciplinary research programme ('BioMareau'project) is currently being conducted from 2012 to 2019, focusing on biodiversity recolonization and on interactions and feedbacks between biotic and abiotic components. (Marc M. Villar) 16 May 2020
  • [hal-01594930] Réponses et adaptations aux changements globaux : quels enjeux pour la recherche sur la biodiversité ? Prospective de recherche.

    Réponses et adaptations aux changements globaux : quels enjeux pour la recherche sur la biodiversité ? Prospective de recherche. (Ophélie Ronce) 26 Sep 2017
  • [anses-04608634] Avis de l'Anses relatif à « la catégorisation de Euplatypus hintzi »

    Dans le cadre de la surveillance des organismes réglementés ou émergents (SORE), un dispositif de piégeage a été déployé par la DGAL1 en 2021 avec l’appui de l’INRAE et de l’ONF2. L’objectif de ce dispositif est d’effectuer une surveillance passive dans les sites d’entrée potentiels (ports, aéroports, marché d’intérêt national (MIN)) des organismes réglementés ou émergents (SORE). Ce piégeage est qualifié de « large spectre » car il peut concerner plusieurs filières de production suivies dans le cadre de la SORE (forêts, jardins et espaces verts et infrastructures (JEVI), arboriculture fruitière) en ciblant cependant majoritairement les insectes coléoptères ravageurs des ligneux. Les principes de la surveillance mise en œuvre s’appuient sur les résultats précédemment acquis dans le cadre du projet PORTRAP, utilisant des pièges génériques multi-composés pour la détection précoce d’insectes exotiques xylophages dans les sites potentiels d’entrée sur le territoire national. Les pièges ont été disposés sur 13 sites (7 ports maritimes, 1 port fluvial, 4 aéroports et 1 marché national) dispersés sur le territoire (France métropolitaine continentale). Au total 9279 individus appartenant à 110 espèces différentes ont été capturés. Aucune espèce d’insecte de quarantaine prioritaire n’a été piégée. En revanche, la présence d’individus appartenant à 8 espèces de coléoptères exotiques, a priori non présents sur notre territoire, des familles Cerambycidae et Curculionidae (sous-familles des Scolytinae et Platypodinae) a été relevée. Les 8 espèces d’insectes exotiques sont les suivantes : - Cerambycidae : Cordylomera spinicornis (Fabricius, 1775), Trichoferus campestris (Faldermann, 1835), Xylotrechus chinensis (Chevrolat, 1852), Xylotrechus stebbingi Gahan, 1906 ; - Curculionidae : Amasa sp. near truncata, Euplatypus hintzii (Schaufuss, 1897), Euplatypus parallelus (Fabricius, 1801), Xyleborus affinis Eichhoff, 1868. (Jean-Claude Gregoire) 11 Jun 2024
  • [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. (Antoine Guiguet) 10 Oct 2023
  • [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. (S.W. A'Hara) 29 May 2020

    A major goal of the Atacama Large Millimeter/submillimeter Array (ALMA) is to make accurate images with resolutions of tens of milliarcseconds, which at submillimeter (submm) wavelengths requires baselines up to ~15 km. To develop and test this capability, a Long Baseline Campaign (LBC) was carried out from September to late November 2014, culminating in end-to-end observations, calibrations, and imaging of selected Science Verification (SV) targets. This paper presents an overview of the campaign and its main results, including an investigation of the short-term coherence properties and systematic phase errors over the long baselines at the ALMA site, a summary of the SV targets and observations, and recommendations for science observing strategies at long baselines. Deep ALMA images of the quasar 3C138 at 97 and 241 GHz are also compared to VLA 43 GHz results, demonstrating an agreement at a level of a few percent. As a result of the extensive program of LBC testing, the highly successful SV imaging at long baselines achieved angular resolutions as fine as 19 mas at ~350 GHz. Observing with ALMA on baselines of up to 15 km is now possible, and opens up new parameter space for submm astronomy. (Alma Partnership) 22 Apr 2015
  • [hal-01607783] No saturation in the accumulation of alien species worldwide

    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. (Hanno Seebens) 27 May 2020
  • [hal-02629243] Global rise in emerging alien species results from increased accessibility of new source pools

    Our ability to predict the identity of future invasive alien species is largely based upon knowledge of prior invasion history. Emerging alien species-those never encountered as aliens before-therefore pose a significant challenge to biosecurity interventions worldwide. Understanding their temporal trends, origins, and the drivers of their spread is pivotal to improving prevention and risk assessment tools. Here, we use a database of 45,984 first records of 16,019 established alien species to investigate the temporal dynamics of occurrences of emerging alien species worldwide. Even after many centuries of invasions the rate of emergence of new alien species is still high: Onequarter of first records during 2000-2005 were of species that had not been previously recorded anywhere as alien, though with large variation across taxa. Model results show that the high proportion of emerging alien species cannot be solely explained by increases in well-known drivers such as the amount of imported commodities from historically important source regions. Instead, these dynamics reflect the incorporation of new regions into the pool of potential alien species, likely as a consequence of expanding trade networks and environmental change. This process compensates for the depletion of the historically important source species pool through successive invasions. We estimate that 1-16% of all species on Earth, depending on the taxonomic group, qualify as potential alien species. These results suggest that there remains a high proportion of emerging alien species we have yet to encounter, with future impacts that are difficult to predict. (Hanno Seebens) 27 May 2020
  • [hal-02623059] Plant diversity drives global patterns of insect invasions

    During the last two centuries, thousands of insect species have been transported ( largely inadvertently) and established outside of their native ranges worldwide, some with catastrophic ecological and economic impacts. Global variation in numbers of invading species depends on geographic variation in propagule pressure and heterogeneity of environmental resistance to invasions. Elton's diversity-invasibility hypothesis, proposed over sixty years ago, has been widely explored for plants but little is known on how biodiversity affects insect invasions. Here we use species inventories from 44 land areas, ranging from small oceanic islands to entire continents in various world regions, to show that numbers of established insect species are primarily driven by diversity of plants, with both native and non-native plant species richness being the strongest predictor of insect invasions. We find that at large spatial scales, plant diversity directly explains variation in non-native insect species richness among world regions, while geographic factors such as land area, climate and insularity largely affect insect invasions indirectly via their effects on local plant richness. (Andrew M. Liebhold) 26 May 2020
  • [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. (Ulf Büntgen) 26 May 2020
  • [hal-03655936] ACTIAS-WF workflow for a better account of biodiversity

    [...] (Liliana Ballesteros-Mejia) 30 Apr 2022
  • [hal-03655937] From DNA-barcode libraries to global macroecology and macroevolutionary studies in insects

    [...] (Rodolphe Rougerie) 30 Apr 2022
  • [hal-01536447] Stay out (almost) all night contrasting responses in flight activity among tropical moth assemblages

    Variations in diel activity among hyperdiverse tropical communities of moths, despite representing a key component of niche partitioning between species, have barely been studied so far. Using light trapping from dawn to sunset over a 1-year period in French Guiana, we investigated these variations within and between two families of moths (Sphingidae and Saturniidae). Our results revealed contrasting patterns in flight activity at night between Sphingidae and Saturniidae. Sphingidae reached their peak in species richness and abundance between 7:00 and 8:00 p.m., followed by a decrease around 11:00 p.m. to midnight, whereas Saturniidae were continuously present throughout the night, with a peak around midnight. In addition, we found changes in diel activity among some of the most common genera in each family, highlighting distinct behavioral, physiological, and functional traits among taxa. Given differences in flight activity at different taxonomic levels, it is strongly recommended to monitor by light trapping throughout the night to effectively sample saturniid and sphingid assemblages, even though the activity of Sphingidae sharply declines after midnight. These results improve the general natural history information of tropical moths and reinforce the need of further research on the ecological and taxonomic consequences of differences in diel activity. (Greg Lamarre) 11 Jun 2017
  • [hal-02108696] The ECOTROP field school: Inventorying Afro-tropical invertebrate biodiversity through student activities and the use of DNA barcoding.

    Tropical ecosystems have been popularized as the most biodiverse habitats on Earth. However, biodiversity research in the tropics has mainly focused on charismatic vertebrates and higher plants so far, neglecting invertebrates that represent the bulk of local species richness. As a consequence, our knowledge of tropical invertebrate communities remains strongly impeded by both Linnaean and Wallacean shortfalls, and identifying species in a study site often remains a formidable challenge that inhibits the use of these organisms as indicators for ecological and conservation studies. Here, we present a summary of the results of sampling activities conducted by students during the ECOTROP field-school, a training program in tropical ecology where African and European students gained training in fieldwork and study design, and became involved in the front-end processing of samples for DNA barcoding. Most of the activities were oriented towards local surveys of invertebrate biodiversity in forest and savannah ecosystems of the northern section of Lope National Park in Gabon. During five successive editions of the program, a totalof more than 12 500 invertebrates were sampled, and more than 11 000 barcodes were generated. More data will be added in the near future through the processing of samples obtained from two Malaise traps deployed in a forest and a savannah for 12 months in 2014 and 2015. A total of nearly 3000 Barcode Index Numbers (BINs, as a proxy for species diversity) have been obtained to date, most of which belong to Lepidoptera (1664) and Coleoptera (709). For many groups of interest, the number of BINs observed exceeded the number of species recorded for the country. This highlights how combining standardized sampling, DNA barcoding, and experimental learning can significantly enhance local knowledge of biodiversity and ecological community dynamics, while training young biologists to meet the future challenges of biological conservation. (Thibaud Decaens) 24 Apr 2019
  • [hal-04236301] The evolutionary history of capital-breeding moths through the lens of wild silkmoths (Saturniidae) phylogenomics

    Wild silkmoths (Saturniidae) are large capital-breeding insects with non-feeding adults that have short lifespan entirely devoted to reproduction. They exhibit a dazzling diversity of sizes, forms, and life-histories inviting questions about the role that key traits may have played in spurring out species diversification and biogeographical movements in organisms with such extreme reproductive strategy. Yet, the absence of a robust phylogenetic framework based on comprehensive taxonomic sampling impedes our understanding of their evolutionary history. We analyzed 1,024 ultraconserved elements (UCEs) and their flanking regions to infer the relationships among 338 species of Saturniidae representing all subfamilies, tribes, and genera. We performed dating and historical biogeographic analyses to reconstruct their evolutionary history in space and time. Rather unexpectedly for a taxonomically well-known family such as Saturniidae, the alignment of taxonomic divisions and ranks with our phylogenetic results led us to propose substantial rearrangements of the family classification. Saturniids most likely originated in the Neotropics, shortly after the Cretaceous-Paleogene extinction event (ca 64.0-52.0 Ma). Old World lineages stemmed from two independent colonization events during the Eocene, presumably through the Bering-Land-Bridge. Extant subfamilies showed limited mobility across biogeographical regions, except for Saturniinae, a subfamily now present on all continents but Antarctica. These results provide a framework for the integration of saturniid evolutionary history into further global studies of biodiversity and conservation, as well as for in-depth investigations of the spatial and temporal dynamics in all lineages and of the role that key innovations played in driving species diversification of these capital-breeding moths. (Rodolphe Rougerie) 10 Oct 2023
  • [hal-03419963] Functional and taxonomic responses of tropical moth communities to deforestation

    Global insect decline has recently become a cause for major concern, particularly in the tropics where the vast majority of species occurs. Deforestation is suggested as being a major driver of this decline, but how anthropogenic changes in landscape structure affect tropical insect communities has rarely been addressed. We sampled Saturniidae and Sphingidae moths on 27 farms located in Brazilian Amazonia (Para state) and characterised by different deforestation histories. We used functional traits (forewing length, body mass, wing load, trophic niche breadth and resource use strategy), analysed by combining RLQ and null model analyses, to investigate the responses of their taxonomic and functional diversity to landscape change dynamics and current structure. We found that communities had a higher proportion of large and polyphagous species with low wing load in landscapes with low forest quality and relative cover and high land use turnover. This was mainly due to a significant response to deforestation by saturniids, whereas the more mobile sphingids showed no significant landscape-related pattern. We also observed an overall increase of species richness and functional dispersion in landscapes that have been deforested for a long time when compared with more recent agricultural settlements. Our results highlight the complex way in which landscape structure and historical dynamics interact to shape Neotropical moth communities and that saturniid moths respond clearly to the structure of the surrounding landscape, confirming their potential use as an indicator group for environmental monitoring programmes. (Yenny Correa‐carmona) 30 Apr 2022
  • [hal-03079078] Contrasting responses of habitat conditions and insect biodiversity to pest- or climate-induced dieback in coniferous mountain forests

    Natural disturbances are major drivers of forest dynamics. However, in the current context of anthropogenic global warming, shifts in disturbance regimes are expected. Natural disturbances usually leave biological or structural legacies which are important for early-successional species. Nevertheless, these legacies are usually eliminated by forest managers through salvage logging. Here, we investigated the consequences of forest dieback and the following salvage logging on both forest habitat conditions and saproxylic beetle communities. We conducted our study in two types of conifer-dominated highland forests: Pyrenean silver fir (Abies alba) which has suffered drought-induced dieback and Bavarian Norway spruce (Picea abies) which has suffered bark beetle-induced (Ips typographus) dieback. In both of the forest contexts, dieback provided a biological legacy through an increase in deadwood resources; however, this increase was much greater in the spruce forests. Nonetheless, despite this increase in resources, neither type of forest gained in total abundance or species richness after disturbance, compared to healthy stands. Nevertheless, the species composition of saproxylic beetle composition was significantly affected by dieback in spruce stands, but not in the silver fir forests. In the spruce plots, saproxylic beetles responded positively to the large increase in deadwood in the declining stands, including a very strong positive response from red listed species. Saproxylic beetle assemblages in spruce forests were mainly drove by canopy openness and deadwood amount. In the silver fir plots, we did not observed responses from the saproxylic beetle communities to deadwood amount increase. This lack of response may be explained by the relatively low amount of deadwood generated by the drought-induced dieback. Concerning salvage logging, it caused stronger contrasts in spruce forests than in silver fir forests, where it generally had no significant impact. For example, in spruce forests, salvage logging reduced the density of large snags by 91% and large logs by 87% compared with unharvested declining plots. Most of the significant environmental effects on biodiversity associated with dieback were no longer significant after accounting for the salvaged plots in our study data. Then, forest dieback and salvage logging induced much sharper and stronger effects on environmental and community metrics in the spruce than in the silver fir forests. The contrast between Bavaria and the French Pyrenees seems partly related to dieback severity. Finally, we invite forest managers to conserve biological and structural legacies through patches of deadwood-rich areas. (Jérémy Cours) 07 Jun 2024
  • [hal-03700534] Drought-induced forest dieback increases taxonomic, functional, and phylogenetic diversity of saproxylic beetles at both local and landscape scales

    Context: Many forest ecosystems around the world are facing increasing drought-induced dieback, causing mortality patches across the landscape at multiple scales. This increases the supply of biological legacies and differentially affects forest insect communities. Objectives; We analysed the relative effects of local-and landscape-level dieback on local saproxylic beetle assemblages. We assessed how classical concepts in spatial ecology (e.g., habitat-amount and habitat-patch hypotheses) are involved in relationships between multi-scale spatial patterns of available resources and local communities. Methods: We sampled saproxylic beetle assemblages in commercial fir forests in the French highlands. Through automatic aerial mapping, we used percentage of dead tree crown pixels to assess dieback levels at several nested spatial scales. We analysed beetle taxonomic, phylogenetic and functional diversity related to differing levels of multi-scale dieback. Results: We found that taxonomic, functional, and phylogenetic diversity of saproxylic beetle assemblages significantly benefitted from forest dieback, at both local and landscape scales. We detected significant effects in the multiplicative models combining local and landscape variables only for phylogenetic diversity. Increased landscape-scale dieback also caused a functional specialisation of beetle assemblages, favouring those related to large and welldecayed deadwood. Conclusions: Increasing tree mortality under benign neglect provides conservation benefits by heterogenising the forest landscape and enhancing deadwood habitats. Legacy retention practices could take advantage of unharvested, declining forest stands to promote species richness and functional diversity within conventionally managed forest landscapes. (Jérémy Cours) 07 Jun 2024
  • [hal-03621984] KaruBioNet: a network and discussion group for a better collaboration and structuring of bioinformatics in Guadeloupe (French West Indies)

    Sequencing and other biological data are now more frequently available and at a lower price. Mutual tools and strategies are needed to analyze the huge amount of heterogeneous data generated by several research teams and devices. Bioinformatics represents a growing field in the scientific community globally. This multidisciplinary field provides a great amount of tools and methods that can be used to conduct scientific studies in a more strategic way. Coordinated actions and collaborations are needed to find more innovative and accurate methods for a better understanding of real-life data. A wide variety of organizations are contributing to KaruBioNet in Guadeloupe (French West Indies), a Caribbean archipelago. The purpose of this group is to foster collaboration and mutual aid among people from different disciplines using a ‘one health’ approach, for a better comprehension and surveillance of humans, plants or animals’ health and diseases. The KaruBioNet network particularly aims to help researchers in their studies related to ‘omics’ data, but also more general aspects concerning biological data analysis. This transdisciplinary network is a platform for discussion, sharing, training and support between scientists interested in bioinformatics and related fields. Starting from a little archipelago in the Caribbean, we envision to facilitate exchange between other Caribbean partners in the future, knowing that the Caribbean is a region with non-negligible biodiversity which should be preserved and protected. Joining forces with other Caribbean countries or territories would strengthen scientific collaborative impact in the region. Information related to this network can be found at: Furthermore, a dedicated ‘Galaxy KaruBioNet’ platform is available at: (David Couvin) 30 Mar 2022
  • [hal-01605939] Spatiotemporal heterogeneity of larch budmoth outbreaks in the French Alps over the last 500 years

    In the subalpine forest ecosystems of the French Alps, European larch trees (Larix decidua Mill.) are periodically affected by outbreaks of a defoliating insect, the larch budmoth (Zeiraphera griseana (Hubner, 1799); LBM). To assess the long-term dynamics of LBM populations, we propose a spatiotemporal analysis of a long outbreak chronology reconstruction for the entire French Alps covering the period 1414-2009. This chronology was obtained by analyzing tree ring width (TRW) chronologies collected from 44 larch populations. The evidence of a latitudinal gradient in LBM is an original result that we have related to the "travelling waves" and "epicenter" theory. Wavelet analyses revealed a strong explicit continuous signal for periodicities of 4, 8, and 16 years throughout the entire 1500-2003 time series, except for a loss of power from 1690 to 1790 and since the early 1980s. We hypothesize that these abrupt changes could reflect a physiological response of LBM to past climatic variations. The spatial and temporal variability of LBM outbreaks and the propagation phenomenon in the French Alps highlighted by this study raises questions regarding its future dynamics in response to the expected climate change. (Mélanie Saulnier) 09 May 2018
  • [hal-02622748] Census and contemporary effective population size of two populations of the protected Spanish Moon Moth (Graellsia isabellae)

    Graellsia isabellae is a protected lepidopteran both in France and Spain; however, there has been considerable debate over its conservation status. Recent literature emphasised the need of monitoring population size in the different mountain ranges where this iconic species occurs. We used mark-capture-recapture and genotypes of nine molecular microsatellite markers to estimate the census (N) and contemporary effective population size (N-e) of two Spanish populations extending over similar size areas (10-15 km(2)): Puebla (Eastern Spain) and Ordesa (Western Pyrenees). Only adult males were captured and analysed, as sampling was based on the use of the synthesised female sex pheromone. Estimates of N were rather different in the two populations: 3398 males in Puebla (95% CI = 2875-4145) and 1500 in Ordesa (95% CI = 1229-1932), although the area occupied by the populations was larger and more densely forested in Ordesa than in Puebla. Several lines of evidence pointed to a moderate-large contemporary N-e at Puebla (173-178 individuals) and a one-order of magnitude lower N-e at Ordesa (27-49). Thus, N-e/N ratios were very low (0.026 and 0.01 respectively). We recommend G. isabellae to be classified as of Least Concern under the IUCN criteria; however, the high temporal fragmentation index and the very low values of the N-e/N ratios obtained for this species, as compared with those recorded for most others, are usually taken as indicators of actual threat for their conservation. As a cautionary measure, managers should aim at maintaining gene flow by ensuring connectivity of Pinus sylvestris in these areas. (Neus Mari-Mena) 26 May 2020
  • [hal-01605515] Rediscovery of the endangered species Harpalus flavescens (Coleoptera: Carabidae) in the Loire River

    1. The Loire River is one of the last European large rivers with important sediment dynamics and numerous sandbanks. The extraction of sediment from the riverbed during decades and the construction of levees for flood prevention have strongly affected and shaped the biodiversity of the Loire River. 2. Many species from pioneer riverbanks have been impacted with particular consequences for psammophilous insects. The ground beetle Harpalus (Acardystus) flavescens (Piller & Mitterpacher, 1783), is considered to have disappeared from the Middle Loire River for 40 years and is endangered everywhere in Europe. 3. In 2012 and 2013, we recorded two specimens of H. flavescens in Region Centre-Val de Loire (France), in the course of a survey dedicated to evaluating the impact of fluvial maintenance operations upon sediment and biodiversity dynamics. 4. The presence of H. flavescens may be linked to the interruption of riverbed extractions and the vegetation removal of sandbanks of the Loire River (ecosystem restoration). (Olivier Denux) 25 May 2020
  • [hal-02627982] Developing a list of invasive alien species likely to threaten biodiversity and ecosystems in the European Union

    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. (Helen E. Roy) 26 May 2020
  • [hal-01607810] Seven recommendations to make your invasive alien species data more useful

    Science-based strategies to tackle biological invasions depend on recent, accurate, well-documented, standardized and openly accessible information on alien species. Currently and historically, biodiversity data are scattered in numerous disconnected data silos that lack interoperability. The situation is no different for alien species data, and this obstructs efficient retrieval, combination, and use of these kinds of information for research and policy-making. Standardization and interoperability are particularly important as many alien species related research and policy activities require pooling data. We describe seven ways that data on alien species can be made more accessible and useful, based on the results of a European Cooperation in Science and Technology (COST) workshop: (1) Create data management plans; (2) Increase interoperability of information sources; (3) Document data through metadata; (4) Format data using existing standards; (5) Adopt controlled vocabularies; (6) Increase data availability; and (7) Ensure long-term data preservation. We identify four properties specific and integral to alien species data (species status, introduction pathway, degree of establishment, and impact mechanism) that are either missing from existing data standards or lack a recommended controlled vocabulary. Improved access to accurate, real-time and historical data will repay the long-term investment in data management infrastructure, by providing more accurate, timely and realistic assessments and analyses. If we improve core biodiversity data standards by developing their relevance to alien species, it will allow the automation of common activities regarding data processing in support of environmental policy. Furthermore, we call for considerable effort to maintain, update, standardize, archive, and aggregate datasets, to ensure proper valorization of alien species data and information before they become obsolete or lost. (Quentin J. Groom) 03 Oct 2017
  • [hal-02637388] The EASIN Editorial Board: quality assurance, exchange and sharing of alien species information in Europe

    The European Alien Species Information Network (EASIN) aims to facilitate the exploration of alien species information in Europe, and is recognized as the information system supporting European Union Member States in the implementation of the recently published Invasive Alien Species Regulation. In this paper, we present the role and activities of the EASIN Editorial Board (EB), which is responsible for the quality assurance, safeguarding and constant improvement of EASIN. The EB is supported by a web platform that facilitates online discussions about alien species. This platform creates a virtual community by providing a forum-like interface that is moderated by the EB Members but is freely accessible to the scientific community and the general public. It allows all registered users to make comments, raise questions and share experience and expertise on alien species in Europe. Moreover, it provides a means for exchanging opinions and solving disputes in a transparent way. The overall EB activity is commonly agreed upon procedures and standards. (Konstantinos Tsiamis) 28 May 2020
  • [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. (Agnieszka Sendek) 04 Jun 2024
  • [hal-03598330] Collecting, Rearing, and Preserving Leaf-Mining Insects

    Developing methods to rear phytophagous insects is crucial to reveal the true complexity of interactions between insects and their host plants. Here we focus on leaf-mining insects, an ecological guild across four different orders (Lepidoptera, Diptera, Coleoptera, and Hymenoptera) whose larvae feed inside the leaves of their host plants, producing cavities in the leaf tissue that are known as leaf mines. Besides leaf lamina, some leaf-mining species can also mine leaf petioles and veins, and a few species make cavities in soft shoots, stems, or mine the surface of young fruits and seeds. Most leaf miners are host plant-specific and produce characteristic leaf mines that are remarkably variable among species. Some species are considered important crop, orchard, and forest pests. Despite their fascinating life history, global diversity, and ecological and economic importance, little is known about the biology of most species, in particular in the tropics. Here, we describe methods to collect, rear, and preserve samples of leaf miners with an emphasis on the smallest of Lepidoptera (Carlos Lopez-Vaamonde) 30 Apr 2022
  • [hal-01310179] Force balance in the take-off of a pierid butterfly: relative importance and timing of leg impulsion and aerodynamic forces

    Up to now, the take-off stage has remained an elusive phase of insect flight that was relatively poorly explored compared with other maneuvers. An overall assessment of the different mechanisms involved in force production during take-off has never been explored. Focusing on the first downstroke, we have addressed this problem from a force balance perspective in butterflies taking off from the ground. In order to determine whether the sole aerodynamic wing force could explain the observed motion of the insect, we have firstly compared a simple analytical model of the wing force with the acceleration of the insect's center of mass estimated from video tracking of the wing and body motions. Secondly, wing kinematics were also used for numerical simulations of the aerodynamic flow field. Similar wing aerodynamic forces were obtained by the two methods. However, neither are sufficient, nor is the inclusion of the ground effect, to predict faithfully the body acceleration. We have to resort to the leg forces to obtain a model that best fits the data. We show that the median and hind legs display an active extension responsible for the initiation of the upward motion of the insect's body, occurring before the onset of the wing downstroke. We estimate that legs generate, at various times, an upward force that can be much larger than all other forces applied to the insect's body. The relative timing of leg and wing forces explains the large variability of trajectories observed during the maneuvers. (Gaëlle Bimbard) 03 May 2016
  • [hal-03555250] Climate-induced forest dieback drives compositional changes in insect communities that are more pronounced for rare species

    Species richness, abundance and biomass of insects have recently undergone marked declines in Europe. We metabarcoded 211 Malaise-trap samples to investigate whether drought-induced forest dieback and subsequent salvage logging had an impact on ca. 3000 species of flying insects in silver fir Pyrenean forests. While forest dieback had no measurable impact on species richness, there were significant changes in community composition that were consistent with those observed during natural forest succession. Importantly, most observed changes were driven by rare species. Variation was explained primarily by canopy openness at the local scale, and the tree-related microhabitat diversity and deadwood amount at landscape scales. The levels of salvage logging in our study did not explain compositional changes. We conclude that forest dieback drives changes in species assemblages that mimic natural forest succession, and markedly increases the risk of catastrophic loss of rare species through homogenization of environmental conditions. (Lucas Sire) 03 Feb 2022
  • [hal-03206694] Climate-induced forest dieback drives compositional change in insect communities that is concentrated amongst rare species

    Marked decline in insect species richness, abundance and biomass have recently been quantified in Europe. We metabarcoded 224 Malaise-trap samples to investigate whether drought-induced forest dieback and subsequent salvage logging have an impact on flying insects (ca. 3000 insect species) in silver fir Pyrenean forests. We found no evidence that climate-induced forest dieback impacted species richness of flying insects but revealed compositional turnover patterns consistent with those seen during natural forest succession, given that the key covariates explaining compositional variation were canopy openness versus microhabitat diversity and deadwood amount at local and landscape scales, respectively. Importantly, most change was driven by rare species. In contrast, observed levels of salvage logging did not explain change in species richness or composition. Hence, although forest dieback appears to cause changes in species assemblages mimicking natural forest succession, it also increases the risk of catastrophic loss of rare species through homogenization of environmental conditions. (Lucas Sire) 23 Apr 2021

 Les articles, ouvrages et chapitres d'ouvrages publiés par l'Unité de Recherche de Zoologie Forestière, de 2000 à ce jour, sont disponibles sur la base de données ProdINRA :

 ProdINRA, la base des publications des chercheurs de l'INRA

Vous trouverez ici la liste des publications à comité de lecture des chercheurs de l'URZF durant les dernières années :

Dans cette rubrique

Articles et chapitres d'ouvrage publiés en 2016
Articles et chapitres d'ouvrage publiés en 2015
Articles et chapitres d'ouvrage publiés en 2014
Articles et chapitres d'ouvrage publiés en 2013
Articles et chapitres d'ouvrage publiés en 2012
Articles et chapitres d'ouvrage publiés en 2011

Date de modification : 21 mai 2024 | Date de création : 19 décembre 2016 | Rédaction : RP