Fabrice Requier

• PhD in Ecology
• Researcher at UMR CNRS-IRD-Université Paris-Saclay

1. Many studies have reported honeybee colony losses in human-dominated landscapes. While bee floral food resources have been drastically reduced over past decades in human-dominated landscapes, no field study has yet been undertaken to determine whether there is a carry-over effect between seasonal disruption in floral resource availability and hi...

In temperate regions, the overwintering success of honey bee colonies, Apis mellifera , depends on the last generations of long-lived bees emerging in autumn, known as winter bees. While the physiological qualities of winter bees and their extended lifespan are well documented, yet literature on their flight activity performance is scarce. Here we...

In recent decades, worldwide concerns about the health of honey bees motivated the development of surveys to monitor the colony losses, of which Sub-Saharan Africa has had limited representation. In the context of climate change, understanding how climate affects colony losses has become fundamental, yet literature on this subject is scarce. For th...

Access to adequate pollen sources in agricultural landscapes is critical for the nutrition and development of bees. The type and quantity of pollen available to bees and may be determined by local plant diversity, land-use intensity and landscape structure but different bee species likely respond differently to these parameters. Identifying communi...

Despite their ecological significance, wild Apis mellifera populations remain critically understudied. Addressing this research gap requires the study and monitoring of free-living colonies to identify potential self-sustaining populations. However, a lack of standardized methodologies has hindered these efforts. To address this challenge, Honey Be...

Honey bees are predominantly perceived as a domesticated animal for agricultural purposes, while their role and importance as a wild species is often overlooked. In contrast to managed populations, wild cohorts are shaped by natural selection, which is why they can potentially cope better with threats like Varroa destructor and a changing environme...

Due to the increasing pressures on bees, many beekeepers currently wish to move their managed livestock of Apis mellifera 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...

High winter mortality of honey bees (Apis mellifera) has been observed in temperate regions over the past 30 years. Several biotic and abiotic stressors associated with winter colony losses have been identified, but the mechanisms and interactions underlying their effects remain unclear. We reviewed the effects of stressors on key overwintering bio...

Amid growing ecological concerns surrounding honey bee colony mortality, Precision Apiculture Systems (PAS) emerge as promising monitoring tools to safeguard bee health as well as to improve the beekeeping practices and economic sustainability of apiary operations. These systems offer critical insights into colony dynamics, aiding decision-making p...

Honey bees (Apis mellifera) are exposed to multiple stressors such as pesticides, lack of forage, and diseases. It is therefore a long-standing aim to develop robust and meaningful indicators of bee vitality to assist beekeepers While established indicators often focus on expected colony winter mortality based on adult bee abundance and honey reser...

Over the last quarter century, increasing honey bee colony losses motivated standardized large-scale surveys of managed honey bees (Apis mellifera), particularly in Europe and the United States. Here we present the first large-scale standardized survey of colony losses of managed honey bees and stingless bees across Latin America. Overall, 1736 bee...

Apis mellifera was used as a model species for ecotoxicological testing. In the present study, we tested the effects of acetone (0.1% in feed), a solvent commonly used to dissolve pesticides, on bees exposed at different developmental stages (larval and/or adult). Moreover, we explored the potential effect of in vitro larval rearing, a commonly use...

The Yellow-legged hornet (Vespa velutina nigrithorax) was accidentally introduced into south-western of France in 2004 and rapidly spread throughout France and neighbouring countries. This insect predator hunts honey bees leading to a hornet-mediated beekeeping risk (HBR) with potential mortality of honey bee colonies and important economic costs....

The Western honey bee Apis mellifera is a managed species that provides diverse hive products and contributing to wild plant pollination, as well as being a critical component of crop pollination systems worldwide. High mortality rates have been reported in different continents attributed to different factors, including pesticides, pests, diseases...

Diverse pollinator communities are critical for crop production. The development of urban agriculture raises the question of whether urban habitats can support pollinator communities able to provide a sufficient pollination service to urban crops. Indeed, urban heat islands and light pollution could impact pollinator communities and their activity...

Simple Summary Urban agriculture is a sustainable form of crop production for city-dwellers that requires insect pollinators to produce fruits and vegetables. However, few studies have tested whether urban pollinators are able to support the production of these urban crops. We carried out a study in an urban area near Paris (France) to test whether...

Insect-mediated pollination is essential for crop production but is mainly studied considering diurnal pollinators only. Using pollinator exclusion techniques to prevent either diurnal or nocturnal insect visits we estimate the contribution of day-active and night-active pollinators to fruit set, seed set, fruit weight and fruit volume in three ber...

Introducing any species in a large number into an ecosystem is never a zero-sum game. In this paper, we assessed what are the main advances on the known impacts of Massively Introduced Managed Species (MIMS) on plant–pollinator communities and networks. We first focused on the raising body of literature studying the effects of the introduction of h...

Over the last quarter century, increasing bee colony losses motivated standardized large-scale surveys of managed honey bees ( Apis mellifera ), particularly in Europe and the United States. Here we present the first large-scale standardized survey of colony losses of managed honey bees and stingless bees across Latin America. Overall, 1736 beekeep...

Learning is the process through which skills, knowledge, behaviors are acquired and developed. Through life experiences, pollinator insects, learn to associate odor or visual stimuli from flowers with a rewarding food as pollen or nectar. This capability allows them to obtain resources efficiently and provides a valuable pollination service. Here,...

Biological invasions have ecological impacts worldwide with potential massive economic costs. Among other ecosystem services such as nitrogen cycle, carbon sequestration and primary production, invasive alien species are particularly known to impact pollination. By predating honey bees (Apis mellifera), the invasive Yellow-legged hornet (Vespa velu...

Abstract Automated 3D image‐based tracking systems are new and promising devices to investigate the foraging behavior of flying animals with great accuracy and precision. 3D analyses can provide accurate assessments of flight performance in regard to speed, curvature, and hovering. However, there have been few applications of this technology in eco...

The risk of poisoning bees by sprayed pesticides depends on the attractiveness of plants and environmental and climatic factors. Thus, to protect bees from pesticide intoxication, an usual exemption to pesticide regulations allows for spraying on blooming flowers with insecticides or acaricides when no bees are foraging on crops. Nevertheless, deci...

Pollinators are critical for food security; however, their contribution to the pollination of locally important crops is still unclear, especially for non-bee pollinators. We reviewed the diversity, conservation status, and role of bee and non-bee pollinators in 83 different crops described either as important for the global food market or of local...

The nests of social insects often harbor a rich fauna of intruders, known as inquilines. Close relatedness between the host and the inquiline prevails due to potential genetic predispositions but how phylogenetically distant inquilines adapt to their hosts remains unclear. Here, we analyzed the genome of the wingless and blind bee louse fly Braula...

Automated 3D-image based tracking systems are new and promising devices to investigate the foraging behaviour of flying animals with great accuracy and precision. 3D analyses can provide accurate assessments of flight performance in regard to speed, curvature, and hovering. However, there have been few applications of this technology in ecology, pa...

The overall objective of SafeAgroBee is to contribute to adaptation and mitigation of the effects of climate change and other drivers negatively influencing the sustainability and the resilience of the agricultural system in the Mediterranean basin, ensuring the income of farmers and food security. In SafeAgroBee we focus on beekeeping and pollinat...

Pollination services provided by a diversity of pollinators are critical in agriculture since they enhance the yield of many crops. However, few studies have assessed pollination services in urban agricultural systems. We performed flower-visitor observations and pollination experiments on strawberries, Fragaria × ananassa , in an urban area of Par...

Environmental gradients generate and maintain biodiversity on Earth. Mountain slopes are among the most pronounced terrestrial environmental gradients, and the elevational structure of species and their interactions can provide unique insight into the processes that govern community assembly and function in mountain ecosystems. We recorded bumble b...

Wild bee populations are declining due to human activities, such as land use, which strongly affect the composition and diversity of available plants and food sources. The chemical composition of food (i.e. nutrition), in turn, determines health, resilience and fitness of bees. However, for pollinators, the term health is recent and subject to deba...

Biotic pollination and pest control are two critical insect-mediated ecosystem services that support crop production. Although management of both services is usually treated separately, the new paradigm of Integrated Pest and Pollinator Management (IPPM) suggests synergetic benefits by considering them together. We reviewed the management practices...

Many parts of the globe experience severe losses and fragmentation of habitats, affecting the self-sustainability of pollinator populations. A number of bee species coexist as wild and managed populations. Using honey bees as an example, we argue that several management practices in beekeeping threaten genetic diversity in both wild and managed pop...

Patterns of resource use by animals can clarify how ecological communities have assembled in the past, how they currently function and how they are likely to respond to future perturbations. Bumble bees (Hymentoptera: Bombus spp.) and their floral hosts provide a diverse yet tractable system in which to explore resource selection in the context of...

Pesticide risk-assessment guidelines for honeybees (Apis mellifera) generally require determining the acute toxicity of a chemical over the short-term through fix-duration tests. However, potential long-lasting or delayed effects resulting from an acute exposure (e.g. a single dose) are often overlooked, although the modification of a developmental...

Temperature and photoperiod are important Zeitgebers for plants and pollinators to synchronize growth and reproduction with suitable environmental conditions and their mutualistic interaction partners. Global warming can disturb this temporal synchronization since interacting species may respond differently to new combinations of photoperiod and te...

Changes in agricultural practices have led to pollination deficits in entomophilous crops, leading to a growing interest in supplementing farmlands with managed colonies of honey bee, Apis mellifera. However, the metrics of a colony as a pollination unit is controversial due to the wide range of adult population sizes encountered in a colony, espec...

Insect communities vary seasonally with changing climatic conditions and related changes in resource availability, strength of competition, or pressure by natural antagonists. But seasonal dynamics, particularly in tropical mountain ecosystems, are not well understood. We monitored cavity-nesting Hymenoptera communities on Mt. Kilimanjaro, Tanzania...

Context: Global pollinator decline has motivated much research to understand the underlying mechanisms. Among the multiple pressures threatening pollinators, habitat loss has been suggested as a key contributing factor. While habitat destruction is often associated with immediate negative impacts, pollinators can also exhibit delayed responses over...

Assessing the various anthropogenic pressures imposed on honeybees requires characterizing the patterns and drivers of natural mortality. Using automated lifelong individual monitoring devices, we monitored worker bees in different geographical, seasonal and colony contexts creating a broad range of hive conditions. We measured their life-history t...

https://theconversation.com/les-insectes-ces-super-heros-148956

Assessing the various anthropogenic pressures imposed on honeybees requires characterizing the patterns and drivers of natural mortality. Using automated lifelong individual monitoring devices, we monitored worker bees in different geographical, seasonal and colony contexts creating a broad range of hive conditions. We measured their life-history t...

Measuring time–activity budgets over the complete individual life span is now possible for many animals with the recent advances of life‐long individual monitoring devices. Although analyses of changes in the patterns of time–activity budgets have revealed ontogenetic shifts in birds or mammals, no such technique has been applied to date on insects...

Flower abundance and diversity benefit bee populations. However, flower resource availability is disturbed in farmlands and little is known about which protein or carbohydrate resources may limit bee fitness. Here, we test the hypothesis of complementary resource limitation using a novel experimental approach of supplemental feeding in differently...

Measuring time-activity budgets over the complete individual lifespan is now possible for many animals with the recent advances of life-long individual monitoring devices. Although analyses of changes in the patterns of time-activity budgets have revealed ontogenetic shifts in birds or mammals, no such technique has been applied to date on insects....

Resource availability in agricultural landscapes has been disturbed for many organisms, including pollinator species. Abundance and diversity in flower availability benefit bee populations; however, little is known about which of protein or carbohydrate resources may limit their growth and reproductive performance. Here, we test the hypothesis of c...

Land-use change and habitat loss have profoundly disturbed the resource availability for many organisms in farmlands, including bees. To counteract the resulting decline of bees and to maintain their pollination service to crops, bee pollinator-friendly schemes have been developed. We assessed the most established bee pollinator-friendly schemes wh...

The alarming loss of pollinator diversity world‐wide can reduce the productivity of pollinator‐dependent crops, which could have economic impacts. However, it is unclear to what extent the loss of a key native pollinator species affects crop production and farmer's profits. By experimentally manipulating the presence of colonies of a native bumbleb...

Citizen science is a powerful tool for connecting members of the public with research and for obtaining large amounts of data. However, it is far less commonly implemented in developing countries than in developed countries. We conducted a large‐scale citizen‐science program monitoring honey bee (Apis mellifera) colony losses in Argentina to examin...

The western honey bee Apis mellifera is a native species from Africa, Europe, and Western Asia. This species evolved four evolutionary lineages that present a large diversity of 31 subspecies. In the 17th century, various European subspecies were introduced in Latin America. More recently, in 1957, the African subspecies A. m. scutellata was subseq...

The western honey bee Apis mellifera plays an important role in human well-being by producing honey, sustaining populations of wild plants and supporting human-dependant crop production. Unfortunately, abnormal high-mortality rates of colonies have been revealed all over the world. This paper reviews the stress factors that are likely involved in t...

Recent studies reveal the use of tree cavities by wild honeybee colonies in European forests. This highlights the conservation potential of forests for a highly threatened component of the native entomofauna in Europe, but currently no estimate of potential wild honeybee population sizes exists. Here, we analyzed the tree cavity densities of 106 fo...

When honey bees (Apis mellifera) feed on flowers they extend their proboscis to absorb the nectar, i.e. they perform the proboscis extension response (PER). The presence of pollen and/or nectar can be associated with odors, colors or visual patterns, which allows the bee to recognize food sources in the environment. Bees can associate similar, thou...

The Asian hornet is an invasive predator of honey bees in Western Europe. The Asian hornet-related risk of bee colony mortality has motivated the development of biological and physical control methods over the past years. Although the technical cost-benefit ratio has been established for most of these control methods, it is still unclear whether su...

Recent studies have emphasized the role of the western honey bee, Apis mellifera, as a managed agricultural species worldwide, but also as a potential threat to endangered wild pollinators. This has resulted in the suggestion that honey bees should be regulated in natural areas to conserve wild pollinators. We argue that this perspective fails to a...

Predicting the resilience of biodiversity-driven functions in agroecosystems to drivers of environmental change (EC) is of critical importance to ensure long-term and environmentally safe agricultural production. However, operationalizing resilience of such functions is challenging, because conceptual approaches differ, direct measures are difficul...

Introduced in France more than a decade ago from China, the invasive Asian hornet Vespa velutina preys on honey bee Apis mellifera foragers at hive entrances and is a major concern for Western European beekeepers and governmental policies. Asian hornet predation is suspected to weaken honey bee colonies before the winter season. In this study, we a...

Latin America is a region with an important and growing apicultural industry and a high diversity of wild bees. Over the last years, the global decline of wild bees and the numerous reports of high colony losses of managed bees have motivated an increase in research on bees in the region. These studies have contributed to improve our understanding...

Due to the widespread use of pesticides and their persistence in the environment, non-target organisms are chronically exposed to mixtures of toxic residues. Fungicides, herbicides and insecticides are all found at low doses in the diet of pollinators such as honey bees, but due to the lack of data on the toxicological effects of these mixtures, de...

Over the past decade, several countries have carried out monitoring programs of managed honey bee colonies, which suggest beekeeping difficulties, with high colony loss rates all over the world. Although Latin America plays a major role in the global honey supply, information about trends in beekeeping activities and honey bee colony losses are lac...

The honey bee (Apis mellifera L.) has been spread all over the world by humans and is now the most widespread bee invasive species. In spite of being considered a beneficial species, there is a controversy around its impact on natural habitats caused by its high densities. Here we review the most important effects and mechanisms attributed to an in...

Understanding how ecosystem services interact to support crop yield is essential for achieving food security. Here we evaluate the interactions among biotic pest regulation, pollination, and nutrient cycling. We found only 16 studies providing 20 analyses of two-way interactions. These studies show that multiple services limit crop yield simultaneo...

Several countries have carried out surveys of managed honeybee colonies, the results of which suggest high loss rates all over the world. Although Latin America is an important apicultural location, estimates of honeybee colony losses are lacking. This study quantified colony losses in Argentina during the 2015-16 season. Overall, the survey includ...

Over the past decade, several countries have carried out monitoring of managed honey bee colonies suggesting high losses all over the world. Although Latin America plays a major role in the global honey supply, estimates of honey bee colony losses are lacking. Using the FAO dataset we reveal a worrying situation for apiculture in Latin America, whe...

Au cours des cinquante dernières années, les paysages agricoles ont été profondément modifiés en réponse à une intensification des pratiques agricoles. En a résulté une perte d’habitats semi-naturels et une érosion de la biodiversité appauvrissant la disponibilité en ressources florales, l’unique ressource alimentaire des abeilles. Bien qu’un tiers...

Pollination deficits are widespread in current agriculture, so improving management for crop pollination is critical. Here we review the two most common management approaches to enhance crop pollination, species and habitat management, by providing referenced lists of successful examples. We pinpoint that these approaches have been studied in isola...

Environ 20 000 espèces d’abeilles sont présentes dans le monde, dont près de 2000 en Europe. Leur comportement de butinage est à l’origine d’un service de pollinisation indispensable au fonctionnement des écosystèmes et à de nombreuses productions agricoles. Pourtant, ce mariage entre l’agriculture et les abeilles est fragile. L’agriculture est sou...

Ce sont les images du miel et de la ruche qui viennent généralement à l'esprit lorsqu'on évoque le mot "abeille". Pourtant, en Europe, le miel est produit par une seule espèce, l'abeille mellifère (Apis mellifera L.) tandis que le mot "abeille" rassemble une diversité écologique remarquable. Après avoir illustré les éléments qui rassemblent les abe...

The data available came from part of ECOBEE, a long term ecological research program set up to monitor honeybee colonies in a context of real professional beekeeping practices in the Poitou-Charentes region in central western France (46°23’N, 0°41’W). Over five consecutive years, from 2008 to 2012, the colony dynamics were monitored by measuring th...

The concerns for the effects of honey bee declines have spurred several large-scale surveys of honey bee health around the world to evaluate potential drivers of colony losses. United States and Europe already have well developed honey bee surveys, however, no large-scale survey is yet developed in South America. In this paper, we present such an i...

Bee declines are driven by multiple combined stresses, making it exceedingly difficult to identify experimentally the most critical threats to bees and their pollination services. We highlight here the too often ignored potential of mechanistic models in identifying critical stress combinations. Advanced bee models are now available as open access...

Ecology studies often require large datasets. The benefits of citizen science for collecting such datasets include the extension of spatial and temporal scales, and cost reduction. In classical citizen science, citizens collect data and send them directly to scientists. This may not be possible for the many biological groups for which specimen iden...

Défi technologique relevé : les trajectoires d’envol et d’atterrissage de milliers d’abeilles sont désormais décryptables en 3D. L’utilisation de la stéréovision en apiculture permet désormais d’étudier les troubles comportementaux des abeilles en vol dans un contexte de vidéosurveillance des colonies in natura.