Short-term responses of ground-dwelling arthropod communities to habitat loss and fragmentation in experimental mesoscale landscapes.

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.

BeeFunc, a comprehensive trait database for French bees.

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.

Contrasting effects of climate and anthropogenic change on future invasion risk of a solitary bee Amegilla pulchra.

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.

Exploring the bee fauna on the islands of Brittany (France): an initial survey reveals a remarkable species richness.

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.

Bees of the Mediterranean basin: biodiversity insights from specimens in the IMBE collection (Marseille, France).

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.

Land Use Change Consistently Reduces α- But Not β- and γ-Diversity of Bees.

Land 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.

Neglecting non-bee pollinators may lead to substantial underestimation of competition risk among pollinators.

Due to the increasing pressures on bees, many beekeepers currently wish to move their managed livestock of into little disturbed ecosystems such as protected natural areas. This may, however, exert detrimental competitive effects upon local wild pollinators. While it appears critical for land managers to get an adequate knowledge of this issue for effective wildlife conservation schemes, the frequency of this competition is not clear to date.

Apoidea of the collections of Lyon, Aix-en-Provence, Marseille and Toulon Museums of Natural History (France).

Background: Many insect species have shown dramatic declines over the last decades, as a result of man-related environmental changes. Many species which were formerly widespread are now rare. To document this trend with evidence, old records of collected specimens are vital.

Checklist of the bees (Hymenoptera, Apoidea) of New Caledonia.

Background: In a world where insects and notably bees are declining, assessing their distribution over time and space is crucial to evaluate species status and highlight conservation priorities. However, this can be a daunting task, especially in areas such as tropical oceanic islands where exhaustive samplings over time have been lacking. This is the case in New Caledonia, an archipelago located in the southwest Pacific.

Effects of litter quality on foraging behaviour and demographic parameters in (Collembola).

Litter quality has long been associated with demographic parameters of Collembola populations. However, little is known about the capacity of Collembola to perceive and seek better litter quality. To address this gap, three complementary laboratory experiments were carried out with the Collembola .

Microbiota and pathogens in an invasive bee: Megachile sculpturalis from native and invaded regions.

The present study aimed to characterise the bacterial, fungal and parasite gut community of the invasive bee Megachile sculpturalis sampled from native (Japan) and invaded (USA and France) regions via 16S rRNA and ITS2 amplicon sequencing and PCR detection of bee microparasites. The bacterial and fungal gut microbiota communities in bees from invaded regions were highly similar and differed strongly from those obtained in Japan. Core amplicon sequence variants (ASVs) within each population represented environmental micro-organisms commonly present in bee-associated niches that likely provide beneficial functions to their host.

On the road: Anthropogenic factors drive the invasion risk of a wild solitary bee species.

Complex biotic networks of invaders and their new environments pose immense challenges for researchers aiming to predict current and future occupancy of introduced species. This might be especially true for invasive bees, as they enter novel trophic interactions. Little attention has been paid to solitary, invasive wild bees, despite their increasing recognition as a potential global threat to biodiversity.

Landscape and Local Drivers Affecting Flying Insects along Fennel Crops (, Apiaceae) and Implications for Its Yield.

Agricultural landscapes are increasingly characterized by intensification and habitat losses. Landscape composition and configuration are known to mediate insect abundance and richness. In the context of global insect decline, and despite 75% of crops being dependent on insects, there is still a gap of knowledge about the link between pollinators and aromatic crops.

Wild insect diversity increases inter-annual stability in global crop pollinator communities.

While an increasing number of studies indicate that the range, diversity and abundance of many wild pollinators has declined, the global area of pollinator-dependent crops has significantly increased over the last few decades. Crop pollination studies to date have mainly focused on either identifying different guilds pollinating various crops, or on factors driving spatial changes and turnover observed in these communities. The mechanisms driving temporal stability for ecosystem functioning and services, however, remain poorly understood.

Evidence for multiple introductions of an invasive wild bee species currently under rapid range expansion in Europe.

Background: Invasive species are increasingly driving biodiversity decline, and knowledge of colonization dynamics, including both drivers and dispersal modes, are important to prevent future invasions. The bee species Megachile sculpturalis (Hymenoptera: Megachilidae), native to East-Asia, was first recognized in Southeast-France in 2008, and has since spread throughout much of Europe. The spread is very fast, and colonization may result from multiple fronts.

Effects of Urbanization on Plant-Pollinator Interactions in the Tropics: An Experimental Approach Using Exotic Plants.

Land-use changes through urbanization and biological invasions both threaten plant-pollinator networks. Urban areas host modified bee communities and are characterized by high proportions of exotic plants. Exotic species, either animals or plants, may compete with native species and disrupt plant-pollinator interactions.

Below-ground competition alters attractiveness of an insect-pollinated plant to pollinators.

Competitive interactions between plants can affect patterns of allocation to reproductive structures through modulation of resource availability. As floral traits involved in plant attractiveness to pollinators can be sensitive to these resources, competition with any neighbouring species may influence the attractiveness of insect-pollinated plants. While pollination research has primarily focused on above-ground interactions, this study aims at investigating if the presence of a competitor plant can modulate neighbouring insect-pollinated plant attractiveness to pollinators and resulting fecundity, especially through below-ground competitive interactions for soil resources.

Pollinator Specific Richness and Their Interactions With Local Plant Species: 10 Years of Sampling in Mediterranean Habitats.

In the context of global pollinator decline, little is known about the protection status and ecology of many species. This lack of knowledge is particularly important for Mediterranean protected areas that harbor diverse pollinator communities and are subject to considerable anthropogenic pressures. Calanques National Park (85 km2), which is located near Marseille (France), is dominated by Mediterranean low-vegetation habitats, such as phrygana and scrublands.

Wild pollinator activity negatively related to honey bee colony densities in urban context.

As pollinator decline is increasingly reported in natural and agricultural environments, cities are perceived as shelters for pollinators because of low pesticide exposure and high floral diversity throughout the year. This has led to the development of environmental policies supporting pollinators in urban areas. However, policies are often restricted to the promotion of honey bee colony installations, which resulted in a strong increase in apiary numbers in cities.

Range expansion of the Asian native giant resin bee (Hymenoptera, Apoidea, Megachilidae) in France.

In 2008, a new species for the French bee fauna was recorded in Allauch near Marseille: the giant resin bee, (Smith, 1853). This was the first European record of this species that is native to East Asia. To our knowledge, it is the first introduced bee species in Europe.

The proportion of impervious surfaces at the landscape scale structures wild bee assemblages in a densely populated region.

Given the predicted expansion of cities throughout the world, understanding the effect of urbanization on bee fauna is a major issue for the conservation of bees. The aim of this study was to understand how urbanization affects wild bee assemblages along a gradient of impervious surfaces and to determine the influence of landscape composition and floral resource availability on these assemblages. We chose 12 sites with a proportion of impervious surfaces (soil covered by parking, roads, and buildings) ranging from 0.

Plant pollinator networks along a gradient of urbanisation.

Background: Habitat loss is one of the principal causes of the current pollinator decline. With agricultural intensification, increasing urbanisation is among the main drivers of habitat loss. Consequently studies focusing on pollinator community structure along urbanisation gradients have increased in recent years.