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A breeding population of the tree-killing European spruce bark beetle Ips typographus was detected in England for the first time in 2018 and was initially assumed to have arrived with infested timber. To test the hypothesis that the beetles are dispersing naturally across the English channel, extensive trap networks were deployed in 2021 and 2022 to track the flight activity of the beetles from an outbreak hotspot in France and Belgium to southern England, including parallel ‘coastal’ traps on either side of the channel. Beetles were caught all along the transect, decreasing in abundance with distance from the outbreak area. Linear modelling indicates that beetles dispersed into England during 2021 and 2022, and that during a large-scale dispersal event in June 2021, beetles could have penetrated more than 160 km inland. The 2021 dispersal event initiated new incursions of the beetle in southeast England and demonstrates the extraordinary distance I. typographus may move under outbreak conditions. Our findings support the hypothesis of a damaging forest pest aerially dispersing across the barrier of the English channel and suggest that future incursions of this and other plant-associated pests may move via the same pathway., SCOPUS: ar.j, info:eu-repo/semantics/published

La stratégie de reproduction des hyménoptères eusociaux (fourmis, abeilles et guêpes sociales) est remarquable. La spermatogenèse a lieu dans les testicules des mâles pendant la phase nymphale: ils émergent avec un stock fini de spermatozoïdes, lesquels migrent vers les testicules accessoires où ils sont stockés jusqu'à l'éjaculation. L’accouplement est généralement limité à un bref vol nuptial, après lequel les sexués mâles et femelles ne s’accoupleront plus jamais. Les mâles meurent rapidement après l’accouplement, mais persistent à titre posthume sous la forme de spermatozoïdes stockés dans la spermathèque des reines. Ces dernières utilisent ces spermatozoïdes pour féconder leurs oeufs pendant toute leur vie, qui peut durer plusieurs décennies chez certaines espèces. Dans ce contexte, le succès reproducteur des mâles et des reines est intimement lié à la qualité de l'éjaculat et aux capacités de stockage à long terme des reines.Dans cette thèse, nous avons abordé quatre aspects de la biologie reproductive des fourmis. Premièrement, nous avons évalué les effets de la compétition spermatique sur la qualité de l'éjaculat et la taille des glandes accessoires au sein du genre Cataglyphis. Nous avons constaté que la compétition spermatique est positivement corrélée avec la production et la viabilité spermatique, ainsi que la taille des glandes accessoires. Cependant, elle n'est pas associée à la fragmentation de l'ADN des spermatozoïdes. Deuxièmement, chez la fourmi des jardins Lasius niger, nous avons montré que la qualité spermatique (viabilité et fragmentation de l’ADN) au sein des testicules accessoires des mâles n'était pas négativement impactée par la durée de stockage pré-éjaculation. Troisièmement, nous avons mesuré les variations de viabilité spermatique dans la spermathèque des reines L. niger sur une période d'un an post-accouplement. Nos résultats montrent un accroissement de la proportion des spermatozoïdes vivants avec le temps, ce qui suggère que les rei, Option Biologie des organismes du Doctorat en Sciences, info:eu-repo/semantics/nonPublished

Stingless bees are important pollinators and producers of honey used in folk medicine. We investigate the nectar sources for two Afrotropical stingless bee species, Hypotrigona araujoi and Meliponula ferruginea .Pollen was extracted and processed using next‐generation sequencing (NGS) methods, DNA metabarcoding. Results show that stingless bees visited 32 plant genera. Wild plants were the major nectar sources for the two stingless bees' species. The diversity of plants visited and honey physical–chemical characteristics differed between the two bee species, suggesting that they use comparable spectra of host plants. This information should help prioritise the conservation of identified forage plants., SCOPUS: ar.j, info:eu-repo/semantics/published

While new species of termites are described every year, the description of species distant from every known termite species is rare. In this paper, we describe one such species, Engelitermes zambo sp.n. an African Termitidae belonging to an entirely new lineage of termites for which we create a new subfamily, Engelitermitinae subfam.n. The subfamily status of Engelitermitinae was supported by termite phylogenetic trees, including sequences from the four existing samples of E. zambo sp.n. which, albeit with low bootstrap supports, placed Engelitermes gen.n. on a long branch sister to Forficulitermes ,the two of which formed the sister group of a clade comprising Cubitermitinae, Nasutitermitinae, Syntermitinae and all other Termitinae. The sister relationship between Engelitermes gen.n. and Forficulitermes is further supported by the similar gut structure of their workers. In contrast, the soldiers of Engelitermes gen.n. resemble those of Cephalotermes .Our phylogenetic analyses, including all clades of Termitinae, call for a global taxonomic revision of the Termitinae subfamily names. Finally, our study highlights that new unique termite lineages are still awaiting to be described., SCOPUS: ar.j, info:eu-repo/semantics/published

In the context of the sixth mass extinction, our understanding of insect decline is severely limited by a lack of information on biodiversity. Many highly abundant and diverse insect groups remain unidentifiable to species or even to genus. The parasitoid wasp superfamily Platygastroidea is one such “dark taxon”. The taxonomic impediment is especially severe in the Palearctic Platygastrinae due to the proliferation of names with vague concepts. Platygastrine wasps parasitize the hyper-diverse Cecidomyiidae (Diptera), suggesting that their species richness may be correspondingly high. Revisionary work is needed to identify named species and to discover new ones. This work applies integrative taxonomic methods to address the most pressing problems within the subfamily. The research presented in this dissertation focuses on Europe, particularly Germany, which is the current center of insect decline research as well as a historical center of platygastrine taxonomy. As part of this work, historical descriptions and their associated type material were examined and clarified so that further revisionary work can occur. The dissertation is structured in five chapters, of which two are published and three are unpublished. The first chapter reviews 18 genera of Platygastridae described by Arnold Förster (1856), most of which represent distinct and recognizable lineages. The study provides their taxonomic history, diagnostic remarks, English translations, and illustrations of important specimens from the Förster collection in the Natural History Museum Vienna. The collection also includes original exemplar specimens of European species whose types have been lost. Potential neotypes and lectotypes from this material are noted, with the aim of improving nomenclatural stability in the group. Potential neotypes were found for Amblyaspis forticornis (Nees, 1834), Isocybus grandis (Nees, 1834), Platygaster striolata Nees, 1834, and Trichacis tristis (Nees, 1834). Lectotypes will be d, Mitten im sechsten Massensterben ist unser Verständnis des Insektenrückgangs durch mangelhafte Informationen über die biologische Vielfalt noch immer stark eingeschränkt. Viele der häufigen und artenreichen Insektengruppen lassen sich nicht bis zur Art oder Gattung bestimmen, verweilen daher im Dunkeln. Platygastroidea, eine Überfamilie parasitoider Wespen, stellt ein solches "dark Taxon" dar. Bei paläarktischen Platygastrinae ist die taxonomische Bearbeitung besonders schwer, da es in einer Vielzahl von Taxa Unklarheiten gibt. Platygastrinae parasitieren die sehr artenreichen Cecidomyiidae (Diptera), was darauf schließen lässt, dass ihr Artenreichtum ebenfalls entsprechend groß sein könnte. Taxonomische Revisionen sind erforderlich, um beschriebene Arten zu identifizieren und neue zu entdecken. Die vorliegende Arbeit nutzt integrative Taxonomie, um die dringendsten Probleme dieser Unterfamilie anzugehen. Der Forschungsschwerpunkt liegt auf Europa, insbesondere Deutschland, das aktuelle Zentrum der Erforschung des Insektensterben, sowie ein historisches Zentrum der Platygastrinen-Taxonomie. Die Dissertation ist in fünf Kapitel unterteilt, von denen zwei veröffentlich und drei unveröffentlicht sind. Das erste Kapitel liefert einen Überblick über die 18 von Arnold Förster (1856) beschriebenen Gattungen der Platygastridae. Informationen über ihre Taxonomie, Anmerkungen zur Diagnose, Übersetzungen sowie Abbildungen wichtiger Exemplare aus der Förster-Sammlung im Naturhistorischen Museum Wien werden bereitgestellt. Die Sammlung Förster enthält zudem wichtige Original-Exemplare europäischer Arten, deren Typen unauffindbar sind. Potenzielle Neotypen und Lectotypen aus diesem Material sind vermerkt, um die nomenklatorische Stabilität der Gruppe zu verbessern. Potenzielle Neotypen wurden für Amblyaspis forticornis (Nees, 1834), Isocybus grandis (Nees, 1834), Platygaster striolata Nees, 1834, und Trichacis tristis (Nees, 1834) gefunden. Lectotypen werden für P. spinigera Nees

Les sociétés d'insectes sont considérées comme des systèmes complexes, hautement organisés et efficaces. Leur symbolique dans la culture populaire renvoie une image d’animaux particulièrement actifs. Cependant, il existe des niveaux d’activité au sein de la colonie très variables avec des taux particulièrement faibles de l’ordre 20 à 30%. En outre, certaines ouvrières sont inactives et immobiles, et semblent n’être impliquées dans aucune tâche. À ce jour, notre connaissance de la valeur fonctionnelle associée à ces niveaux d’activité interne montre des lacunes importantes. L’objectif de cette thèse est de caractériser les fluctuations des niveaux d’activité interne à l’échelle coloniale et individuelle au sein des fourmilières de l’espèce Myrmica rubra et de mieux comprendre leur impact sur les comportements collectifs de récolte de nourriture et de migration vers un nouveau nid.Nous avons tout d’abord testé si les individus fortement inactifs se distinguent des autres groupes fonctionnels (i.e. fourrageuses, domestiques et nourrices) quant à leurs réponses à des stimuli environnementaux. Ces inactives ont montré des niveaux de réponse proches des nourrices et domestiques. Confrontées à des larves, les inactives sont les ouvrières les plus enclines à les transporter. Ceci suggère que leur inactivité n’est pas causée par un dysfonctionnement dans la perception des stimuli environnementaux ou par des seuils de réponse plus élevés que les autres fourmis internes. À l’échelle du groupe, nous avons caractérisé les variations d’activité interne et constaté l’existence de fluctuations non périodiques mais présentant un degré de synchronisation. Nous avons montré que le niveau moyen d’activité interne d’une colonie est stable sur plusieurs jours mais baisse suite à un affamement prolongé. Cette baisse d’activité combinée à une synchronisation accrue des ouvrières apparait comme une stratégie d’économie d’énergie en situation de jeûne. Nos résultats ont également révélé que, Doctorat en Sciences, info:eu-repo/semantics/nonPublished

Pollinators play a crucial role in ecosystems globally, ensuring the seed production of most flowering plants. They are threatened by global changes and knowledge of their distribution at the national and continental levels is needed to implement efficient conservation actions, but this knowledge is still fragmented and/or difficult to access. As a step forward, we provide an updated list of around 3000 European bee and hoverfly species, reflecting their current distributional status at the national level (in the form of present, absent, regionally extinct, possibly extinct or non-native). This work was attainable by incorporating both published and unpublished data, as well as knowledge from a large set of taxonomists and ecologists in both groups. After providing the first National species lists for bees and hoverflies for many countries, we examine the current distributional patterns of these species and designate the countries with highest levels of species richness. We also show that many species are recorded in a single European country, highlighting the importance of articulating European and national conservation strategies. Finally, we discuss how the data provided here can be combined with future trait and Red List data to implement research that will further advance pollinator conservation., SCOPUS: ar.j, SCOPUS: ar.j, info:eu-repo/semantics/published

Scolytinae is a subfamily of weevils that contains many major pest species. Most scolytines employ an outbreeding mating system: individuals emerge from their natal host trees and fly to new hosts, where they mate with unrelated conspecifics. However, in several outbreeding species, some individuals mate prior to emergence, either with a sibling or an unrelated neighbor from another gallery. Preemergence mating allows females to start adult life with a supply of sperm; they can then dig a gallery on their own in a new host tree. In this study, we examined preemergence mating in Ips typographus, a supposedly outbred bark beetle that causes considerable damage to European spruce forests. Our field and laboratory studies have shown that 15–94% of females are mated at (re)emergence, a wide range of values that is shaped by environmental conditions and time of year. This figure is also positively correlated with time spent under the bark. Moreover, in laboratory experiments, outbreeding females had the same level of productivity whether they established themselves with a partner or on their own. However, compared to both types of outbreeding females, solitary inbreeding females exhibited lower productivity due to higher mortality in the egg and postlarval stages, suggesting the presence of inbreeding depression. In a choice experiment, females preferentially entered nuptial chambers containing unrelated males versus brothers. These results shed new light on this bark beetle’s mating behavior, which ultimately influences the species’ ability to colonize new areas., SCOPUS: ar.j, info:eu-repo/semantics/published

The weevil genus Cryptolarynx Van Schalkwyk, 1966 is endemic to the Northern and Western Cape provinces of South Africa. The two previously known species of the genus, C. vitis (Marshall, 1957) and C. estriatus (Marshall, 1957), have an aberrant globular body and head shape, which has made it difficult to place the genus into the classification systems of the Curculionoidea. This paper presents the description of 21 new species of Cryptolarynx from South Africa (C. subglaber Haran sp. nov., C. squamulatus Haran sp. nov., C. muellerae Haran sp. nov., C. hirtulus Haran sp. nov., C. robustus Haran sp. nov., C. namaquanus Haran sp. nov., C. carinatus Haran sp. nov., C. variabilis Haran sp. nov., C. pyrophilus Haran sp. nov., C. pilipes Haran sp. nov., C. armatus Haran sp. nov., C. falciformis Haran sp. nov., C. oberprieleri Haran sp. nov., C. spinicornis Haran sp. nov., C. cederbergensis Haran sp. nov., C. homaroides Haran sp. nov., C. marshalli Haran sp. nov., C. endroedyi Haran sp. nov., C. oberlanderi Haran sp. nov., C. san Haran sp. nov., and C. luteipennis Haran sp. nov.) and of one new genus and species, Hadrocryptolarynx major Haran gen. et sp. nov., also from South Africa. A redescription of the genus Cryptolarynx is provided to incorporate the characters of the new species. The plant genus Oxalis (Oxalidaceae) is recorded as larval host for several species of Cryptolarynx and for Hadrocryptolarynx Haran gen. nov., as their larvae develop in the subterranean bulbs of members of the genus, and the egg, larva and pupa of C. variabilis are described. The characters of the Cryptolarynx larva confirm that Cryptolaryngini are an early-diverging group of Curculionidae, with a placement among taxa currently classified in the subfamily Brachycerinae sensu lato, and although their exact taxonomic position remains unresolved, some larval characters, and also pupal ones, suggest a close relationship between Cryptolaryngini and Stenopelmus Schoenherr. Potential use of specie

The sentinel plantation concept consists of assessing the impact of exotic factors, such as pests and pathogens, on plants of interest by planting them out of their native range. This tool is a way to enhance knowledge for pest risk analysis (PRA) by guiding decisions on how quarantine organisms should be regulated and where to focus prevention and surveillance efforts for an early detection. In this study, the sentinel method was used in the case of research on Xylella fastidiosa, a plant pathogenic bacterium that has recently been found established in southern Europe, but whose potential impact and possible host range are still poorly documented in northern areas where the bacterium is not known to occur. To improve knowledge on the susceptibility of potential hosts of X. fastidiosa in northern Europe, a sentinel plantation of Prunus domestica cv. Opal, Quercus petraea and Salix alba was established in the X. fastidiosa-infected area of Majorca. In order to assess the circulation of the bacterium in the sentinel plot and around it, surveys of the local flora and insect vectors were carried out, as well as the planting of a network of rosemary “spy plants". Symptomatic monitoring and molecular analyses were performed on the sentinel plants for four years. During these years, X. fastidiosa was never detected in our sentinel plants most likely because of the low infectivity pressure recorded in the surroundings. This study underlines the complexity of conducting sentinel plantation assays combined with X. fastidiosa research, highlighting the need for long-term investigation and questioning the efficiency of the sentinel tool. However, this study is placed in perspective with other valuable sentinel plantations. It also highlights the complementarity of the tool and proposes elements to improve or re-orientate the implementation of future sentinel projects., info:eu-repo/semantics/published

Fire is an important cause of disturbance which directly shapes many ecosystems worldwide. While the effect of fire on the distribution and regeneration of plant species has been widely documented, little is known on how phytophagous insects are reacting to these disturbances. This study explores the survival strategies of various weevil species, a highly diverse phytophagous beetle group in fire-prone ecosystems of the biodiversity hotspot of the Cape Floristic Region in South Africa. More specifically, we investigated how the lifestyle of species (location of larval development, phenology of adults, and flight ability) correlates with heat tolerance. We hypothesized that wingless species in particular will show better tolerance to heat as they have a limited ability to escape fire rapidly and usually remain hidden in the soil. The thermal tolerance of a set of sixteen species with divergent lifestyles and geographic distribution was measured using a standard heat knockdown protocol at 48°C. Respirometry was then performed on the most resistant species using a ramping protocol in order to determine CTmax. Our results show that the species tested exhibit high variation in thermal tolerance across taxonomic groups, clustering into three modalities: weak, intermediate, and high tolerance to heat stress. In addition, life history traits (diurnal vs. nocturnal adult activity and location of juvenile stages in plant tissues) likely better explain thermal tolerance at the species level than flight ability or the fire-proneness of ecosystems. Finally, results revealed that some non-flying weevil species are highly heat tolerant with CTmax values reaching up to 50.2 and 51.9°C in species among the Ocladiinae and Brachycerinae subfamilies, respectively. Climate change is leading to an increase in the impact and frequency of fires. In this context, this study highlights the diversity of strategies developed by arthropods to escape extreme heat in fire prone ecosystems. Furthe

Madagascar is home to many endemic plant and animal species owing to its ancient isolation from other landmasses. This unique fauna includes several lineages of termites, a group of insects known for their key role in organic matter decomposition in many terrestrial ecosystems. How and when termites colonised Madagascar remains unknown. In this study, we used 601 mitochondrial genomes, 93 of which were generated from Malagasy samples, to infer the global historical biogeography of Neoisoptera, a lineage containing more than 80% of described termite species. Our results indicate that Neoisoptera colonised Madagascar between 7 and 10 times independently during the Miocene, between 8.4 and 16.6 Ma (95% HPD: 6.1–19.9 Ma). This timing matches that of the colonization of Australia by Neoisoptera. Furthermore, the taxonomic composition of the Neoisopteran fauna of Madagascar and Australia are strikingly similar, with Madagascar harbouring an additional two lineages absent from Australia. Therefore, akin to Australia, Neoisoptera colonised Madagascar during the global expansion of grasslands, possibly helped by the ecological opportunities arising from the spread of this new biome., SCOPUS: ar.j, info:eu-repo/semantics/published

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This commentary paper addresses the outdated and misleading terminology used to categorize termites into “higher” and “lower”. These terms perpetuate a linear progression view of evolution, which is both inaccurate and detrimental to our understanding of the diversity of life. We trace the historical origins of these terms and highlight their flawed interpretation of evolutionary relationships. We advocate for the adoption of Termitidae (or termitid), rather than “higher termites”. As for the paraphyletic group of “lower termites”, we recommend refraining from grouping them together, unless specifically referring to their symbionts. In such cases, we propose “protist-dependent termites” or “non-Termitidae termites”., SCOPUS: no.j, info:eu-repo/semantics/published

The neotropical Apicotermitinae is a common and widespread clade of mostly soil-feeding soldierless termites. With few exceptions, species of this group were originally assigned to the genus Anoplotermes Müller, 1873. The application of internal worker morphology coupled with genetic sequencing has recently shed light on the true diversity of this sub-family. Herein, Anoplotermes susanae Scheffrahn, Carrijo & Castro, sp. nov. and four new species in four new genera are described: Hirsutitermes kanzakii Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov. Krecekitermes daironi Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov. Mangolditermes curveileum Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov. and Ourissotermes giblinorum Scheffrahn, Carrijo & Castro, gen. nov. et sp. nov. Worker descriptions are based mainly on worker gut morphology, including the enteric valve, while imagoes were described based on external characters. A Bayesian phylogenetic tree of New World Apicotermitinae was constructed using the complete mitogenome to infer genera relationships and corroborate the taxonomic decisions. Distribution maps and a dichotomic key to the known Neotropical Apicotermitinae genera are provided., SCOPUS: ar.j, info:eu-repo/semantics/published

Le défoliateur du niébé (Ootheca mutabilis) qui était considéré comme ravageur mineur du niébé (Vigna unguiculata L. Walp) cause de nos jours des dégâts importants à cette culture dans les zones tropicales humides d’Afrique. Les attaques des adultes peuvent entraîner une réduction de la surface photosynthétisante (jusqu'à 95 %) des feuilles due à la multiplication des lésions foliaires et à la défoliation. Une infestation sévère peut détruire complètement la culture. Une bonne connaissance de l’insecte incriminé et la reconnaissance de ses dégâts sur les plants de niébé s’avère nécessaire pour un meilleur contrôle de ce ravageur. Cette fiche technique présente l’insecte nuisible, la reconnaissance de ses dégâts, ainsi qu’une stratégie de méthode de lutte efficace basée sur de bonnes pratiques agricoles et sur une utilisation rationnelle des insecticides chimiques de synthèse à base de cyperméthrine, de deltaméthrine, et de lambdacyhalothrine.

Termites are social cockroaches distributed throughout warm temperate and tropical ecosystems. The ancestor of modern termites roamed the earth during the early Cretaceous, suggesting that both vicariance and overseas dispersal may have shaped the distribution of early diverging termites. We investigate the historical biogeography of three early diverging termite families –Stolotermitidae, Hodotermitidae and Archotermopsidae (clade Teletisoptera) – using the nuclear rRNA genes and mitochondrial genomes of 27 samples. Our analyses confirm the monophyly of Teletisoptera, with Stolotermitidae diverging from Hodotermitidae + Archotermopsidae approximately 100 Ma. Although Hodotermitidae are monophyletic, our results demonstrate the paraphyly of Archotermopsidae. Phylogenetic analyses indicate that the timing of divergence among the main lineages of Hodotermitidae + Archotermopsidae are compatible with vicariance. In the Stolotermitidae, however, the common ancestors of modern Porotermes Hagen and Stolotermes Hagen are roughly as old as 20 and 35 Ma, respectively, indicating that the presence of these genera in South America, Africa and Australia involved over-water dispersals. Overall, our results suggest that early diverging termite lineages acquired their current distribution through a combination of over-water dispersals and dispersal via land bridges. We clarify the classification by resolving the paraphyly of Archotermopsidae, restricting the family to Archotermopsis Desneux and Zootermopsis Emerson and elevating Hodotermopsinae (Hodotermopsis Holmgren) as Hodotermopsidae (status novum)., SCOPUS: ar.j, info:eu-repo/semantics/published

Monitoring is an important component in pest management, to prevent or mitigate outbreaks of native pests and to check for quarantine organisms. Surveys often rely on trapping, especially when the target species respond to semiochemicals. Many traps are available for this purpose, but they are bulky in most cases, which raises transportation and deployment issues, and they are expensive, which limits the size and accuracy of any network. To overcome these difficulties, entomologists have used recycled material, such as modified plastic bottles, producing cheap and reliable traps but at the cost of recurrent handywork, not necessarily possible for all end-users (e.g. for national plant-protection organizations). These bottle-traps have allowed very large surveys to be conducted, which would have been impossible with standard commercial traps, and we illustrate this approach with a few examples. Here, we present, under a Creative Commons BY-SA License, the blueprint for a fan-trap, a foldable model, laser cut from a sheet of polypropylene, which can rapidly be produced in large numbers in a Fab lab or by a commercial company and could be transported and deployed in the field with very little effort. Our first field comparisons show that fan-traps are as efficient as bottle-traps for some Scolytinae species and we describe two cases where they are being used for monitoring., SCOPUS: ar.j, info:eu-repo/semantics/published

Modeling the potential spread of Xylella fastidiosa can document contingency plans in northern Europe, so far uncolonized by the bacterium. Through mark–release–recapture (MRR) and flight-mill experiments, the flight capacity of two potential vectors for temperate Europe was studied: Philaenus spumarius, the reported southern European vector, and Aphrophora salicina, a xylem-specialist feeding on potential host plants of X. fastidiosa. Aphrophora salicina displayed significantly better flight performances than P. spumarius. In flight-mills, the average distance flown was, respectively, 623 m vs. 102 m and the maximal distance flown was 6.16 km vs. 1.54 km in 2.5 h. In MRRs, A. salicina travelled more than 30 m in a single flight, with a maximal interception distance of 80 m after two days, highlighting that dispersal is driven by connectivity and host plant quality. Philaenus spumarius mainly jumped, with 1 m movements in length and a maximal interception distance of 32 m in 27 days. Models estimated P. spumarius' daily mean dispersal at 1.5 m and A. salicina's at 3.5 m. Although only a small part of the population moves over very long distances, this pool of efficient insects could already be sufficient to effectively spread an epidemic. As Salicaceae have been reported as host plants of the bacterium, the association of Aphrophoridae and Salicaceae in riparian areas could create bacterium reservoirs in corridors allowing for transportation over medium to long distances., SCOPUS: ar.j, info:eu-repo/semantics/published

Biodiversity on Earth is experiencing rapidly increasing and unprecedented threats from anthropogenic causes. Around 1 million species have been assessed as threatened with extinction and without decisive actions to reduce the intensity of biodiversity loss mechanisms, extinctions will continue to increase at rates equivalent to those of previous mass extinction events. To objectively assess the state of biodiversity and understand the role and impact of drivers of biodiversity loss at species level, numerous high-quality and robust data are required. However, these data are lacking for many species in nearly all groups of living species. Wild bees constitute the most important group of pollinators of flowering plants, including many crops. This key ecosystem service is under threat by declines of their populations, induced by anthropogenic factors, and documented by several studies. Despite their importance, research on wild bees still faces prominent knowledge gaps, which hinder the description of their ecology and diversity, the assessment of their status in face of decline factors, and ultimately their conservation. Consequently, the overall objective of this thesis is to provide a comprehensive scheme for the study of wild bees from the identification of gaps, through robust data collection, to the prediction of diversity patterns and the impact of local and larger scale factors. This thesis investigated, for the first time, spatial patterns of wild bee diversity and knowledge gaps (i.e. shortfalls) at a continental scale (Europe) using the largest ever compilation of occurrence records (chapters 3 and 4). Our results show that genuine hotspots of wild bee diversity in Europe are hosted in xeric, warm areas, as highlighted by a clear latitudinal gradient, indicating that bees have kept an ancestral link with xeric climates (chapter 3). Despite major advances over the past few decades, our understanding of wild bee diversity, declines and distribution in Europe, La biodiversité sur Terre est confrontée à des menaces d’origine anthropique sans précédent et qui ne cessent de se multiplier. Environ un million d'espèces ont à ce jour été reconnues comme menacées d'extinction. Et l'absence d'actions décisives visant à réduire l'intensité des mécanismes d’appauvrissement de la biodiversité, les extinctions continueront à augmenter à des rythmes équivalents à ceux des précédents événements d'extinction massive. Pour évaluer objectivement l’état de la biodiversité et comprendre le rôle et l'impact des facteurs de perte de biodiversité au niveau des espèces, il est essentiel de disposer de données nombreuses, robustes et de haute qualité. Or, ces données font défaut pour de nombreuses espèces dans presque tous les groupes d'espèces vivantes. Les abeilles sauvages constituent le groupe le plus important de pollinisateurs des plantes à fleurs, parmi lesquelles de nombreuses cultures. Ce service écosystémique essentiel est menacé par le déclin de leur population, induit par des facteurs anthropiques et attesté par plusieurs études. Malgré cela, la recherche sur les abeilles sauvages est toujours entravée par d’importantes lacunes en termes de connaissances, qui constituent autant d’obstacles à la description de leur écologie et de leur diversité, à l’évaluation de leur statut face aux facteurs de déclin et finalement à leur conservation. Par conséquent, l'objectif général de cette thèse est de fournir un schéma complet pour l'étude des abeilles sauvages, de l'identification des lacunes existantes jusqu’à la prédiction de modèles de diversité et de l’impact des facteurs locaux et à plus grande échelles, en passant par la collecte de données robustes. Cette thèse a permis l’étude, pour la première fois, des schémas spatiaux de la diversité des abeilles sauvages et des lacunes dans les connaissances de cette diversité et ce, à l'échelle continentale (en Europe), en utilisant la plus grande compilation de données d'occurrences jamais rasse, Doctorat en Sciences agronomiques et ingénierie biologique, info:eu-repo/semantics/nonPublished

The diversity of organisms within an ecosystem is essential to its functioning. It ensures a stable provision of goods and services, along with the resilience of many communities facing disturbances. Pollinators are involved in the reproduction cycle of a vast majority of flowering plants and crops, and play an essential role in overall ecosystem functioning. Wild bees constitute the most important group of pollinators worldwide. However, this major role is currently under threat with recent reports describing a global decline of overall communities. There are many different factors involved in these declines, both biotic and abiotic, many of which are induced by human activities and act either isolated or in combination with other factors. Climate, landscape and local factors are the main drivers of bee decline. They tend to influence one another, with synergistic effects also influencing bees in different ways. Many experts are calling for meaningful conservation measures to avoid massive detrimental consequences of multi-stressor interactions on wild bee communities inevitably leading to weakened ecosystem functioning.In regard to the complex interactions between decline factors in the context of human-induced global change, and the central pillar of biodiversity that wild bees represent, this thesis focuses our attention on an in-depth exploration of these intricate links. More specifically, our main objective is to study the relative impacts of decline factors in shaping wild bee communities, at different geographic scales and in different human-modified landscapes. We aimed to (i) disentangle the effects of intertwined factors in different contexts, in order to (ii) question long-held beliefs, and finally (iii) find key drivers for future conservation of wild bee communities.To achieve these aims, we decided to investigate both at a continental (i.e. one crop) and a local scale (i.e. one city). We observed standardized sampling methods to collect data on wild, Doctorat en Sciences agronomiques et ingénierie biologique, info:eu-repo/semantics/nonPublished

Termites are essential components of tropical ecosystems, in which they provide fundamental ecosystem services, such as decomposition of dead plant material, fostering of soil mineralization and provisioning of new microhabitats. We investigated the termite communities of four habitats in two protected areas in West Africa, which differ in management effectiveness: the strictly protected Lamto Reserve (LR) and the Marahoué National Park (MNP), which suffers from anthropogenic disturbance despite its protection status. We tested the effect of disturbance on species composition, richness and abundance as well as on functional (feeding type) composition. The effect of disturbance was clearly visible in the termite communities. Compared to the LR, the MNP had less termite species overall and in all habitats except the shrub savannah. Also the abundance of termites was generally reduced and a decrease of soil feeders recorded. The latter is well-known to be sensitive to anthropogenic disturbance in forests. Comparing our results with other studies, we were able to identify suitable bioindicators of ecosystem health for West-African savannahs. Furthermore, we discuss the potential consequences of anthropogenic disturbance on ecosystem services provided by termites., info:eu-repo/semantics/published

info:eu-repo/semantics/published

Termites are insects found in tropical regions where they play a major ecological role. The objective of this study was to inventory termite species present in the Gourma province in eastern Burkina Faso in relation to habitat variations in order to contribute to the conservation of biodiversity. For this purpose, we sampled nine sites from three habitats (savannahs, fields, and fallows), i.e. three sites per habitat, using a standard rapid harvesting method for two weeks in August 2018. From this sampling, we identified 1285 individuals from which 18 termite species, 11 genera and 2 families. Our collections documented five species and one genus (Schedorhinotermes) recorded for the first time in Burkina Faso. The analysis of occurrence indices revealed that Macrotermes bellicosus was a constant savannah species, and Nasutitermes sp. and Schedorhinotermes sp. were accessory species whereas the majority of the species were rare. The Shannon and equitability indices showed that savannah supported a greater richness of termites (sixteen species) and a more equitable distribution of species, likely because savannah was less disturbed compared with crop fields and fallows and was therefore richer in food resources. Statistical analysis of functional groups revealed significant variation in termite in groups II and IV abundance among sampled habitats probably in relation to soil, vegetation, climate and anthropic disturbances. Our study has provided an update to the list of termite species and highlighted the ecological importance of this taxonomic group in Burkina Faso., SCOPUS: ar.j, info:eu-repo/semantics/published