Rare and endemic plant populations are particularly vulnerable to global human-induced perturbations. Teucrium polium subsp. purpurascens (Benth.) (S. Puech, 1976) (Lamiaceae) is a rare and endangered plant species restricted to the coastal habitats of the Calanques National Park (southern France). Most populations are found on a continental archipelago located at two kilometres from the mainland. To investigate the interactions of Teucrium polium subsp. purpurascens with its flower visitors, we compared the insect’s richness and abundance foraging on this rare species, as well as its relative attractiveness, with those of a widespread close relative Teucrium flavum (L., 1753). Here, we show a strong dichotomy in floral visitors foraging on the two plant species, T. p. purpurascens being visited by a wide diversity of insects while T. flavum attracted almost exclusively bees. The two plant species also have very distinct guilds of visiting bees, with only nine species in common. Moreover, the plants’ attractiveness strategies are widely dissimilar. Teucrium p. purpurascens offers a large number of highly nectar-concentrated flowers to a guild of small, short-tongued bees, while T. flavum produces a larger quantity of less concentrated nectar for a guild of large, long-tongued bees. The differences between the two species in both attractiveness strategies and flower visitor guilds highlight the need to consider plant-flower visitor interdependencies for the conservation of rare and isolated plant species.

Pollination is the basis of ecosystem functioning, as it conditions the reproduction of most flowering plants. With the expected future expansion of the urban environment, evaluating the status of pollination in these habitats becomes essential. Using a two-year replicated experiment carried out on a scale of 16 cities across western Europe, we estimated pollination function in these urban environments, and inferred the effects of local and landscape variables, using white mustard Sinapis alba as a pollinometer, i.e . a model plant species used to estimate pollination function. We found the pollinometer reproductive success to be positively affected by pollinator visitation rates, more specifically by small wild bee visitation rates, which in turn were negatively impacted by urban green space patchiness at the city scale. In contrast, visitation rates of hoverflies, the most abundant floral visitors, were not affected by urban green space configuration and their visitation rate did not impact the reproductive success of the pollinometer. Moreover, the visitation rate of all pollinator categories, except hoverflies, was positively affected by the pollinometer floral display. These results emphasize that urban habitat patchiness may affect pollination function through its impact on a single pollinator functional group, namely the small wild bees, which are not necessarily the most abundant pollinators. These results also highlight the need for more studies on how local management practices of urban green spaces influence pollinator diversity and pollination function.

The loss of natural habitats in agroecosystems is one of the major reasons for the decline in biodiversity. Riparian areas, which are known for their diverse flora and the many insects they support, are particularly vulnerable. Plant-pollinator networks are however far less studied in riparian areas than in other natural habitats such as grasslands, even though they could also be valuable for pollinator biodiversity conservation, especially in agroecosystems. By providing relay resources for pollinators that also visit crops such as rapeseed, riparian areas may also indirectly contribute to crop pollination services in agroecosystems. Based on field sampling, we built grassland and riparian plant-pollinator networks at five different sites in Northwestern France. We also sampled the visitors of rapeseed crops. First, we compared grasslands and riparian areas based on their plant and pollinator community composition and network metrics. Then, we investigated the drivers of pollinator abundance and richness found in these habitats. Finally, we evaluated indirect interactions between rapeseed and the wild flowers of riparian areas and grasslands through shared pollinators. Our results highlighted the interest of both riparian areas and grasslands in agroecosystems. The richness and structure of the networks were not different, and rapeseed pollinators benefited from the floral resources offered by both grasslands and riparian areas.

Fragmented landscapes challenge biodiversity conservation. While connectivity elements are promoted to mitigate the effects of fragmentation, their effectiveness remains debated. This study evaluates the effectiveness of corridors and stepping stones in enhancing dispersal success and population dynamics in a high-resistance matrix. We compare two experimental approaches: a landscape-based design that explicitly accounts for matrix resistance, and a traditional network-based design in which habitat patches are connected by tubes. We conducted a laboratory experiment using the microarthropod model Folsomia candida, manipulating fragmentation by varying the distance between four habitat patches embedded in a high-resistance matrix. Connectivity elements (corridors and stepping stones) were tested and compared with unconnected landscapes (control) and network-based designs. Over 12 weeks, we monitored colonization success, population size, reproduction rate, and adult survival using AI-based image analysis. The presence of corridors as a connectivity element enhanced the colonization of initially empty patches, but their effectiveness was distance-dependent. Stepping stones did not differ from the non-connected control landscapes. Interestingly, the largest total populations were found in the non-connected control landscapes, where restricted dispersal resulted in higher reproduction, indicating a trade-off between movement and reproduction. The highest mortality of released adults was observed in landscapes with corridors, whereas higher recruitment was observed in stepping stones landscapes. Network-based designs yielded a higher population size in initially empty patches compared to landscape-scale designs. However, as they bypassed matrix-related dispersal costs, they led to a miss-estimation of the movement, reproduction, survival and recruitment processes. Connectivity elements can support dispersal and reproduction, but may also increase mortality in resistant matrices. Conservation strategies should incorporate matrix resistance and landscape-scale context to better promote population dynamics in fragmented landscapes.

Insect farming is promoted as a sustainable alternative to traditional livestock, offering substantial reductions in land, water, and feed use while generating fewer greenhouse gas emissions. However, the escape or release of farmed insects into non-native environments may create significant biological invasion risks, with consequences for biodiversity, human well-being, and economies. This study provides the first systematic assessment of the ecological characteristics influencing the likelihood of edible insects becoming invasive, and identifies species not yet reported as invasive that could present risks if farmed outside their native ranges. We evaluated 1,030 species (943 native and 88 introduced) spanning six insect orders (Coleoptera, Lepidoptera, Hymenoptera, Hemiptera, Orthoptera, and Blattodea) in a multidimensional functional space. Our analyses highlight the importance of both larval and adult diet breadth, macroecological factors such as temperature and humidity, and native-range distribution size as predictors of invasion potential. Using machine learning, we identified species with high invasive risk, with Orthoptera, Lepidoptera, Hemiptera, and Hymenoptera being the groups most likely to become invasive. By combining ecological variables with predictive modeling, this work provides a framework for invasion risk assessment and delivers practical guidance to support sustainable insect farming while minimizing ecological threats.

Animal-mediated pollination is essential to our food system: around 75% of crops worldwide depend, at least partially, on floral visitations by animals for their production. Crop pollinators, primarily insects, display an increasing role in global crop yields as the overall surface of animal pollinated crops grows. Yet, insects experience a massive decline worldwide, and pollinators such as bees and dipterans make no exception, potentially threatening crop yield and food security. Identifying insect floral visitors is necessary to build a solid overview of crop-associated pollinators, to enlighten their ecological requirements and the drivers of their subsistence in agricultural landscapes. Surprisingly, while pollinators are central to our food production, basic information on the identity of insect floral visitors remains very limited for many cultivated plants. Here we introduce the first version of a centralised and standardised database called PollAgri, that gathers interaction data between insects and flowers of entomophilous crops in a major agricultural country, Metropolitan France. The database aggregates data thanks to a collaboration with the CropPol project, that provides information on crop pollination worldwide, and a call for contributions to our network of researchers and naturalists. Aggregated data was collected from May 2004 to September 2024 from multiple regions in France. PollAgri gathers 80,935 direct interactions involving 417 insect taxa at various taxonomic ranks, from order to species, for 51 species of cultivated plants. This database is a first step towards the identification of floral visitor communities specific to each crop species, a fundamental requirement to better assess the contribution of insects to crop yield. The database helps pinpoint crops, regions and seasons that are under-sampled, orienting future fieldwork. Furthermore, completed with ecological data on these species, PollAgri will help target pollinator-friendly agricultural practices. Hopefully, the database will stimulate research on crop flower visitors, and encourage the community of naturalists and researchers to share their data and help mitigate pollinator decline and its impacts on both ecosystem stability and food security.

Wild bees (Hymenoptera: Anthophila) and hoverflies (Diptera: Syrphidae), the two major groups of insect pollinators, are undergoing alarming declines worldwide, including Europe. The lack of accessible and verified spatial and temporal occurrence records currently challenges efforts to understand and mitigate this decline. Here, we compiled datasets from diverse sources, including taxonomists, national experts, public repositories, museum collections, published literature, verified open-access platforms, and aggregated datasets from previous European projects. The collected data were standardised, cleaned and validated by taxonomists and national experts. This collective effort resulted in two databases comprising more than 4.34 million and 1.04 million records for wild bees and hoverflies, respectively. The databases cover 97% of the European bee fauna (2,083 species out of 2,138 recorded in Europe) and 97% of the European hoverfly fauna (886 species out of 913 recorded in Europe). These standardised databases constitute essential resources for future assessments of status and trends, habitat associations, and other research and conservation initiatives to protect and understand wild pollinators on the European continent.

The scientific community remains divided on the most effective way to design landscapes for biodiversity conservation or restoration. Although there is a consensus that habitat loss is the main cause of biodiversity decline worldwide, the extent to which fragmentation (i.e. the division of remaining habitats into smaller areas) contributes to this decline is a subject of ongoing debate. The spatial arrangement of remaining patches and the nature and permeability of the intermediate matrix (i.e. how easily animals can move through it) are other elements related to habitat loss that are little considered. A better understanding of the effects of these factors on populations could help the community move forward.Here, we conducted a multigenerational, landscape-scale experiment with the microarthropod Folsomia candida and quantified the respective effects of matrix resistance and inter-patch distance on colonization rate, population size and extinction, at fixed habitat amount. We found that the amount of reachable habitat in the landscape, encompassing both the quantity of habitat and the matrix resistance, is a good predictor of population size and extinction rate. Survival of individuals while crossing different matrix types was the key underlying mechanism, as it determined both colonization rate and demography, preventing individuals from reaching and using remote or difficult-to-access patches. Our study shows that an explicit consideration of matrix resistance considerably improves both our understanding and our predictive ability of populations fate at landscape-scale. It also opens new avenues for landscape ecology theory as well as long-awaited perspectives for applied conservation.

Insect research remains hindered by limited data availability and fragmented knowledge compared to other, better-documented taxonomic groups. Yet, both the macroecological and insect research communities highlight the need to integrate large-scale ecological trait datasets for insects. Insects and humans are interconnected through diverse relationships, ranging from beneficial interactions, such as the use of insects as nutritional resources, to adverse impacts, including their role in biological invasions. Understanding the traits of insects associated with human activities is therefore important for linking insects to ecosystem function and global change. We present AnthropInsect, one of the largest database on insect traits to date, which uniquely includes variables describing human-insect associations. AnthropInsect describes species through 35 variables grouped into five categories: (i) taxonomic descriptors; (ii) ecological descriptors (native bioregions and habitat); (iii) human-insect associations (edibility and invasive status); (iv) functional traits (behavior, morphology, life history and feeding); (v) and macroecological descriptors of native-range geography and climate. AnthropInsect currently includes 5855 species across six major orders: Coleoptera, Lepidoptera, Hemiptera, Hymenoptera, Orthoptera and Blattodea. Data extracted from peer-reviewed, grey literature and from existing databases were standardized and validated with expert knowledge to ensure accuracy. By providing traits data with information on insect–human interactions, this rigorously curated resource supports global research in entomology, ecology, conservation, and global change.

Habitat loss and fragmentation are main drivers of biodiversity decline. However, disentangling their respective effects remains tricky and contrasting results have emerged in previous studies leading to a call for finely designed landscape-scale experiments that compare different levels of habitat fragmentation at fixed habitat loss, and that for different levels of habitat loss. Here we present early-stage results from MESOLAND, a new landscape-scale experiment designed to monitor the response of ground-dwelling arthropod communities to habitat loss and fragmentation, focusing on their short-term responses. Our experiment took place in a dry grassland in France, with natural stone cover representing the habitat and bare soil with stone cover manually removed being the matrix. We thus created experimental landscapes with nine levels of habitat loss (from 0 to 99%) combined with three levels of fragmentation (low, medium, high). Ground-dwelling arthropod communities were monitored using dry pitfall traps during six non-lethal capture sessions. In the months following habitat removal, we observed a drop in the number of captured arthropods with increasing habitat loss. Humidity-dependant groups such as woodlice and silverfish were affected. We observed no effect of habitat fragmentation at any level of habitat loss and no interactive effect with habitat amount. Early-stage results following the implementation of the MESOLAND experiment indicate that habitat loss has a greater effect than habitat fragmentation on ground-dwelling arthropods communities. We expect detecting further effects in the years to come, as most species will have completed several life cycles. The results of this experiment will contribute to the ongoing debate on habitat loss versus fragmentation, providing essential knowledge for applied spatial conservation.

Updated checklist of bees of mainland France (Hymenoptera: Apocrita: Apoidea). - The checklist of bees from metropolitan France is presented here, with an update of the previous checklist published in 1995 which included 865 species. A total of 150 species have been added to this previous checklist, 114 thanks to new distributional records and 36 due to an update of their taxonomic status. In addition, 32 have been removed from the previous list, along with 12 species recently reported in French territory whose presence has either been refuted, deemed doubtful, or requires confirmation. This work results in a list of the 983 confirmed bee species for metropolitan France. This high species richness is related to the high variety of climatic and biogeographic contexts throughout the country. The amount of changes between the previous and the current checklists, most of them related to changes that happened in the past few years, illustrates the importance of keeping our efforts on improving the knowledge of the French bee fauna even today and in the years to come. This update represents an initial step toward supporting these efforts, including the forthcoming red list of French wild bees.

ABSTRACTLand use change threatens global biodiversity and compromises ecosystem functions, including pollination and food production. Reduced taxonomic α‐diversity is often reported under land use change, yet the impacts could be different at larger spatial scales (i.e., γ‐diversity), either due to reduced β‐diversity amplifying diversity loss or increased β‐diversity dampening diversity loss. Additionally, studies often focus on taxonomic diversity, while other important biodiversity components, including phylogenetic diversity, can exhibit differential responses. Here, we evaluated how agricultural and urban land use alters the taxonomic and phylogenetic α‐, β‐, and γ‐diversity of an important pollinator taxon—bees. Using a multicontinental dataset of 3117 bee assemblages from 157 studies, we found that taxonomic α‐diversity was reduced by 16%–18% in both agricultural and urban habitats relative to natural habitats. Phylogenetic α‐diversity was decreased by 11%–12% in agricultural and urban habitats. Compared with natural habitats, taxonomic and phylogenetic β‐diversity increased by 11% and 6% in urban habitats, respectively, but exhibited no systematic change in agricultural habitats. We detected a 22% decline in taxonomic γ‐diversity and a 17% decline in phylogenetic γ‐diversity in agricultural habitats, but γ‐diversity of urban habitats was not significantly different from natural habitats. These findings highlight the threat of agricultural expansions to large‐scale bee diversity due to systematic γ‐diversity decline. In addition, while both urbanization and agriculture lead to consistent declines in α‐diversity, their impacts on β‐ or γ‐diversity vary, highlighting the need to study the effects of land use change at multiple scales.

The substantial loss of insects we are experiencing today has been highlighted all over the world. There is a growing concern about the global decline of pollinators and its impact on terrestrial and agricultural ecosystems, but the focus of scientists towards bees remains the rule. Therefore, the role of other insect taxa in pollination is still overlooked. Our review focused on some of these neglected pollinating taxa, the winged aquatic insects, i.e., insects with an aquatic larval stage such as Ephemeroptera, Trichoptera, Plecoptera (ETP), Megaloptera and some aquatic Diptera. We first documented the visitors of aquatic and wetland flowering plants, anticipating a greater presence of aquatic insects on these plants compared to terrestrial pollinators. Secondly, we documented plant visits, pollen found in gut contents and pollen transfers performed by aquatic insects. Our results revealed a surprisingly low proportion of aquatic insects visiting both aquatic and wetland plants, suggesting a potential gap in the literature. The scarcity of articles dedicated to pollen transfer by aquatic insects also indicates that they are fewly considered in ecological studies. While the role of aquatic insects in pollination is not well documented in the literature, records of their flower visits and pollen found on them or in their gut contents do exist and are promising clues to consider them as effective pollinators. Future research is needed to provide new insights into the importance of winged aquatic insects for the reproductive success of plants, which could also be an argument for the importance of wetland conservation.

Islands are areas where biodiversity conservation is of the utmost importance and is particularly challenging due to the isolation and vulnerability of animal and plant populations. The coastline of Brittany includes a large number of islands, which vary greatly in size, distance from the mainland, landscape composition and climate. Until recently, virtually nothing was known about the bees on these islands, but a number of studies have been carried out in recent years, allowing an initial assessment to be made. The aim of this article is to provide an overview of the bee fauna of the islands of Brittany, in terms of species richness, species composition and rarity status. In total, we gathered records of 188 wild bee species on 25 continental islands, located on both the north and south coasts of Brittany. For most of the islands, we obtained only occasional data, but a few have benefitted from intensive surveys, with data collected throughout the entire flight period and over several years and in different locations and habitat types. For four islands, we considered that the current knowledge is relatively good: Groix (113 wild bee species), Houat (82 species), Hoedic (64 species) and Ouessant (57 species). In addition to the number of species, this study shows that the islands host many species that are rare at regional or national level. Our results highlight the importance of taking bees into account when managing habitats and defining protected areas in islands, in order to conserve both food resources and nesting sites for these pollinator insects.

Amegilla pulchra is a solitary bee from Australia that has recently been spread throughout many islands of the Pacific. The non-regulated human-driven spread of the species may affect the local pollinator communities and their interactions with host plants. We used an ecological niche modelling approach, accounting for non-equilibrium and anthropogenic spread with the most recently recommended methods, and predicted the potential spread of the species under current and future conditions. We expected climate change and increase in human density to offer new suitable environments for the spread of the species. Invasion risks will increase in the future overall, but more in the non-native regions compared to the native region. In the native region, the projected effect of future environmental change was highly contrasted, we projected invasion risk to increase in human-dense areas but decrease elsewhere. We identified high risks of invasion in eastern Asia and in the Caribbean region and provide a world ranking for surveillance priority which accounts for maritime traffic. This study highlights potential contrasted effects between climate and anthropogenic change, with differing projections between the native and the non-native regions. Public awareness and prevention will be key to prevent further spread and mitigate potential adverse effects of the species on island systems. In regions that are already invaded, we propose that habitat restoration is a promising strategy for both the mitigation of the spread and the conservation of local communities.

Given pollinator’s reported decline, it is of utmost importance to better understand the vulnerability of wild bees to human pressures. One way to achieve this goal is to explore how their traits are associated with exposure to anthropogenic perturbations. To date, there is no database synthesizing traits of bees at the species level in France, limiting the functional interpretation of inventories. We present BeeFunc 1.0, the first database on traits for the entire fauna of French wild bees. Based on extensive literature research and expert knowledge, the database is structured according to the French taxonomic register (TAXREF) and its associated knowledge base. The base gathers 26,176 trait information from 483 sources, describing 932 species for 20 features related to morphology, ecology, biogeography, and conservation. BeeFunc is intended to be collaborative and regularly updated. Bees can finally be better considered from a functional perspective. We expect this database to be widely used by researchers, conservationists, naturalists, and stakeholders, stimulating future research on wild bees.

In the context of worldwide biodiversity and wild bee decline, it is increasingly important to better understand the effect of land-use changes on wild bee communities at a global scale. To do so, we studied the effect of city area and urban green spaces layout on wild bee species richness and community composition, as well as on wild bee species with an unfavorable UICN conservation status. This study was based on a large European dataset encompassing 20 cities from France, Belgium and Switzerland. We found a mean wild bee species richness in cities of 96 ± 48 (SD), showing that this species richness was highly variable among cities. The main factor positively influencing wild bee species richness in cities was the area of the city. Conversely, species richness was not significantly related to the total area of urban green spaces in a given city, measured as the spatial extent of urban parks, wastelands and other semi-natural habitats, excluding urban private gardens. Species with conservation status were quite scarce in urban environments, especially when compared to the European Red List of Bees, and we could not link their presence to either city or urban green space area. Dissimilarities in wild bee species community compositions were not associated with any of the studied characteristics of cities. We found that the dissimilarity of wild bee community composition among cities was mainly driven by the rarest species, as the most common ones were found in a majority of the cities sampled. Overall, these results emphasize that larger cities host more wild bee species, but are no refuge for the ones with concerning conservation status. Thus, stakeholders are encouraged to design their cities in favor of biodiversity to better support wild bee communities, and perhaps mitigate the established effect of the urban ecological filter.

Background The spectacular decline in pollinators and their prominent role in pollination of natural and cultivated plants has stimulated research on pollinating insects. Over the last ten years, much ecological research has been carried out on bees, often generating a large volume of specimens and increasing the importance of entomological collections. Here, we present the bee collection of the IMBE laboratory (Marseille, France) after ten years of study of plant-pollinator networks. New information We provide distribution data on 2181 specimens belonging to 246 species of bees, mainly from the Mediterranean Region of France. One of the recorded species, Lasioglossum soror, is classified as "endangered" at the European level, while 68 of the recorded species are currently Data Deficient according to the 2014 Red List of European bees. This dataset contributes to the broader effort to enhance the knowledge of French bee diversity. It aligns with the objectives of the French Pollinator Plan and supports the development of a national Red List. In this context, information about the distribution of wild bees from the Mediterranean Region, which harbours the highest species diversity in mainland France, are of particular importance.