Yves Le Conte

• PhD, HDR
• Research Director at French National Institute for Agriculture, Food, and Environment (INRAE)

Honeybees, Apis mellifera , have experienced the full impacts of globalisation, including the recent invasion by the parasitic mite Varroa destructor , now one of the main causes of colony losses worldwide. The strong selection pressure it exerts has led some colonies to develop defence strategies conferring some degree of resistance to the parasit...

Background Honey bees are the principal commercial pollinators. Along with other arthropods, they are increasingly under threat from anthropogenic factors such as the incursion of invasive honey bee subspecies, pathogens and parasites. Better tools are needed to identify bee subspecies. Genomic data for economic and ecologically important organisms...

In 2017, the European Commission initiated the EurBeST study to explore the possibilities of using selective breeding of honey bees to increase Varroa resistance traits. One of the specific aims of the study was to assess the process of honey bee queen breeding through an economic analysis. The methodology for calculating the costs of queen product...

Automatic monitoring devices placed at the entrances of honey bee hives have facilitated the detection of various sublethal effects related to pesticide exposure, such as homing failure and reduced flight activity. These devices have further demonstrated that different neurotoxic pesticide molecules produce similar sublethal impacts on flight activ...

Honey bees, Apis mellifera , have experienced the full impacts of globalisation, including the recent invasion by the parasite Varroa destructor , hereafter called varroa. This deadly mite has rapidly become one of the main causes of colony losses worldwide, with a huge economic impact on beekeeping. Despite the lethal effects of varroa, some colon...

Simple Summary Honey bees are very important for nature and food production. However, beekeepers’ work is continuously challenged by pests, pathogens, pesticides, and other impacts of the environment on their honey bee colonies, and, therefore, they would greatly benefit from up-to-date insights on the health condition of their bees. To disturb tho...

Invasive vectors can induce dramatic changes in disease epidemiology. While viral emergence following geographical range expansion of a vector is well known, the influence a vector can have at the level of the host's pathobiome is less well understood. Taking advantage of the formerly heterogeneous spatial distribution of the ectoparasitic mite Var...

To ensure the optimal development of brood, a honeybee colony needs to regulate its temperature within a certain range of values (thermoregulation), regardless of environmental changes in biotic and abiotic factors. While the set of behavioural and physiological responses implemented by honeybees to regulate the brood temperature has been well stud...

Information on honeybee foraging performance and especially bee loss rates at the colony level are crucial for evaluating the magnitude of effects due to pesticide exposure, thereby ensuring that protection goals for honeybee colonies are met (i.e. threshold of acceptable effects). However, current methods for monitoring honeybee foraging activity...

Chemical communication is a widely used mode of communication for social insects and has been demonstrated to be involved in many behaviours and physiological processes such as reproduction, nutrition or the fight against parasites and pathogens. In the honey bee, Apis mellifera, the release of chemical compounds by the brood plays a role in worker...

To ensure the optimal development of brood, a honeybee colony needs to regulate its temperature within a certain range of values (thermoregulation), regardless of environmental changes in biotic and abiotic factors. While the set of behavioural and physiological responses implemented by honeybees to regulate the brood temperature has been well stud...

Global pollinator declines threaten food production and natural ecosystems. The drivers of declines are complicated and driven by numerous factors such as pesticide use, loss of habitat, rising pathogens due to commercial bee keeping and climate change. Halting and reversing pollinator declines will require a multidisciplinary approach and internat...

Simple Summary Nosema ceranae is a highly prevalent intracellular parasite of honey bees’ midgut worldwide. There is a lack of studies addressing the influence of climatic and beekeeping factors on the dynamics of its infection. A long-term study has been carried out in six apiaries in four Mediterranean countries (France, Israel, Portugal, and Spa...

Toxicological studies in honeybees have long shown that a single pesticide dose or concentration does not necessarily induce a single response. Inter-individual differences in pesticide sensitivity and/or the level of exposure (e.g., ingestion of pesticide-contaminated matrices) may explain this variability in risk posed by a pesticide. Therefore,...

Background: Eusocial insects are crucial to many ecosystems, and particularly the honeybee (Apis mellifera). One approach to facilitate their study in molecular genetics, is to consider whole-colony genotyping by combining DNA of multiple individuals in a single pool sequencing experiment. Cheap and fast, this technique comes with the drawback of...

Invasive parasites are major threats to biodiversity. The honey bee ectoparasite, Varroa destructor, has shifted host and spread almost globally several decades ago. This pest is generally considered to be the main global threat to Western honey bees, Apis mellifera, although the damages it causes are not equivalent in all its new host's population...

Honey bee subspecies originate from specific geographic areas in Africa, Europe and the Middle East, and beekeepers interested in specific phenotypes have imported genetic material to regions outside of their original range for use either in pure lines or controlled crosses. Moreover, imported drones are present in the environment and mate naturall...

With 2,000 species currently recorded in Europe, bees are a highly diversified and efficient group of pollinating insects. They obtain their nutrients from nectar and pollen of flowers. However, the chemical composition of these resources, especially of pollen (e.g., protein, lipid, amino acids, fatty acids, or sterol content), is highly variable a...

Бюхлер Р., Узунов А., Ильясов Р. А., Коста С., Мейкснер М., Ле Конте И., Мондет Ф., Ковачич М., Андонов С., Каррек Н. Л., Димитров Л., Бассо, Б., Биенковска М., Далл’Олио Р., Хатджина Ф., Вирц У. Проект EURBEST: тестирование пчел на устойчивость к клещу варроа // Пчеловодство. ‒ 2022. № 2. ‒ C. 62-64. (Büchler R., Uzunov A., Ilyasov R. A., Costa C....

EurBeST — A Pilot Study Testing Varroa-resistant Bees Under Commercial Beekeeping Conditions.

Eusocial insects, especially the honeybee (Apis mellifera), are major contributors to many ecosystems and face high levels of biotic and abiotic stress. Living in colonies the unit of interest, for phenotyping, is generally the group, making pool sequencing a relevant genomic tool for estimating genetic contributions. However, due to the multi-male...

In this study, we gathered sequence data from the tRNAleu-cox2 intergenic mitochondrial (mtDNA) region concurrently with single nucleotide polymorphism (SNP) data from 91 loci of nuclear DNA (ncDNA). The data was obtained from 156 colonies sampled in six apiaries from four countries. The full dataset was analysed and discussed for genetic patterns...

Within the context of climate change, winter temperatures at high latitudes are predicted to rise faster than summer temperatures. This phenomenon is expected to negatively affect the diapause performance and survival of insects, since they largely rely on low temperatures to lower their metabolism and preserve energy. However, some insects like ho...

Background Eusocial insects play a central role in many ecosystems, and particularly the important pollinator honeybee ( Apis mellifera ). One approach to facilitate their study in molecular genetics, is to consider whole colonies as single individuals by combining DNA of multiple individuals in a single pool sequencing experiment. Such a technique...

Honey bee subspecies originate from specific geographic areas in Africa, Europe and the Middle East. The interest of beekeepers in specific phenotypes has led them to import subspecies to regions outside of their original range. The resulting admixture complicates population genetics analyses and populations stratification can be a major problem fo...

A reduction in floral resource abundance and diversity is generally observed in agro-ecosystems, along with widespread exposure to pesticides. Therefore, a better understanding on how the availability and quality of pollen diets can modulate honeybee sensitivity to pesticides is required. For that purpose, we evaluated the toxicity of acute exposur...

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...

The invasive mite Varroa destructor is identified as the main biotic cause of European honey bee colony losses in many regions, leading to systematic treatments of colonies every year in order to prevent colonies from collapsing. However, some colonies have been reported to survive in the absence of treatment. The ability of honey bee colonies to s...

With a growing number of parasites and pathogens experiencing large-scale range expansions, monitoring diversity in immune genes of host populations has never been so important because it can inform on the adaptive potential to resist the invaders. Population surveys of immune genes are becoming common in many organisms, yet they are missing in the...

The ectoparasitic mite, Varroa destructor, is unarguably the leading cause of honeybee (Apis mellifera) mortality worldwide through its role as a vector for lethal viruses, in particular, strains of the Deformed wing virus (DWV) and Acute bee paralysis virus (ABPV) complexes. Several honeybee populations across Europe have well-documented adaptatio...

Simple Summary Citizen Science is a valuable resource that can substantially contribute to the conservation of biodiversity. However, its use in honey bee research has remained minimal. The Survivors Task Force of the COLOSS association created and promoted an online surveying tool with the aim of identifying potential cases of Western honey bee, A...

European foulbrood (EFB), caused by Melissococcus plutonius, is a globally distributed bacterial brood disease affecting Apis mellifera larvae. There is some evidence, even if under debate, that spreading of the disease within the colony is prevented by worker bees performing hygienic behaviour, including detection and removal of infected larvae. O...

RNA viruses play a significant role in the current high losses of pollinators. Although many studies have focused on the epidemiology of western honey bee (Apis mellifera) viruses at the colony level, the dynamics of virus infection within colonies remains poorly explored. In this study, the two main variants of the ubiquitous honey bee virus DWV a...

Invasive species events related to globalization are increasing, resulting in parasitic outbreaks. Understanding of host defense mechanisms is needed to predict and mitigate against the consequences of parasite invasion. Using the honey bee Apis mellifera and the mite Varroa destructor, as a host–parasite model, we provide a comprehensive study of...

Comparative studies of genetic diversity and population structure can shed light on the ecological and evolutionary factors governing host-parasite interactions. Even though invasive parasites are considered of major biological importance, little is known about their adaptative potential when infesting the new hosts. Here, the genetic diversificati...

Cell recapping is a behavioural trait of honeybees (Apis mellifera) where cells with developing pupae are uncapped, inspected, and then recapped, without removing the pupae. The ectoparasitic mite Varroa destructor, unarguably the most destructive pest in apiculture world-wide, invades the cells of developing pupae to feed and reproduce. Honeybees...

The growing gap between new evidence of pesticide toxicity in honeybees and conventional toxicological assays recommended by regulatory test guidelines emphasizes the need to complement current lethal endpoints with sublethal endpoints. In this context, behavioral and reproductive performances have received growing interest since the 2000s, likely...

Simple Summary Floral resource availability is one of the keys to preserving the health of bee communities. However, flowers also present a risk of pathogen transmission, as infected pollinators could deposit pathogens while foraging, exposing other pollinators to infection via the consumption of contaminated nectar or pollen. Here, we studied, ove...

Characterizing the genetic diversity of populations allows to better understand their demographic history and their adaptation to selective pressures. Social insects, such as honeybee, live in colonies which ultimately are the relevant evolutionary and selective units for such species. However, performing large scale genetic analyses of honeybees i...

Simple Summary The parasitic mite Varroa destructor is a major challenge to honey bee populations worldwide. Some honey bee populations are resistant to the mite, but most of the commercially used stocks are not and rely on chemical treatment. In this article, we describe known varroa-resistant populations and the mechanisms which have been identif...

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...

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...

Simple Summary Honey bees, Apis mellifera, are currently facing drastic colony losses, some of which lies partially on the infestation by a parasite, varroa destructor. To maintain healthy honey bee colonies breeding for resistance to this infestation seems promising. However, measuring resistance is a tedious task as it is a complex process. One c...

In the current context of worldwide honey bee colony losses, among which the varroa mite plays a major role, hope to improve honey bee health lies in part in the breeding of varroa resistant colonies. To do so, methods used to evaluate varroa resistance need better understanding. Repeatability and correlations between traits such as Mite Non-Reprod...

In this work, we disclose a non-invasive method for the monitoring and predicting of the swarming process within honeybee colonies, using vibro-acoustic information. Two machine learning algorithms are presented for the prediction of swarming, based on vibration data recorded using accelerometers placed in the heart of honeybee hives. Both algorith...

Since its migration from the Asian honey bee (Apis cerana) to the European honey bee (Apis mellifera), the ectoparasitic mite Varroa destructor has emerged as a major issue for beekeeping worldwide. Due to a short history of coevolution, the host–parasite relationship between A. mellifera and V. destructor is unbalanced, with honey bees suffering i...

Division of labour is a key aspect of distributed systems, such as swarm robotics or multi-agent systems. Inspired by social insects known for their task allocation capabilities, most of the models rely on two assumptions: 1) each task is associated with a stimulus, and 2) the execution of this task lowers that stimulus. In short, the stimulus is a...

The ectoparasitic mite Varroa destructor is the most significant pathological threat to the western honey bee, Apis mellifera, leading to the death of most colonies if left untreated. An alternative approach to chemical treatments is to selectively enhance heritable honey bee traits of resistance or tolerance to the mite through breeding programs,...

The ectoparasitic mite Varroa destructor is the most significant pathological threat to the western honey bee, Apis mellifera, leading to the death of most colonies if left untreated. An alternative approach to chemical treatments is to selectively enhance heritable honey bee traits of resistance or tolerance to the mite through breeding programs,...

Exposure to multiple stress factors is believed to contribute to honey bee colony decline. However, little is known about how co-exposure to stress factors can alter the survival and behavior of free-living honey bees in colony conditions. We therefore studied the potential interaction between a neonicotinoid pesticide, thiamethoxam, and a highly p...

Throughout western Europe, the endemic honeybee subspecies Apis mellifera mellifera, the black bee, has gradually been replaced in many beekeeper operations by other subspecies and hybrids of A. m. ligustica, A. m. carnica, A.m. caucasica, (C-type bees) and A. m. mellifera (M-type bees), which were found to be more efficient producers of honey or r...

The Asian yellow-legged hornet Vespa velutina nigrithorax, a major predator of honeybees, is spreading in Europe in part due to a lack of efficient control methods. In this study, as a first step to identify biological control agents, we characterized viral RNA sequences present in asymptomatic or symptomatic hornets. Among 19 detected viruses, the...

Honey bees play a critical role in the maintenance of plant biodiversity and sustainability of food webs. In the last few decades, bees have been subjected to biotic and abiotic threats causing various colony disorders. Therefore, monitoring solutions to help beekeepers to improve bee health are necessary. MALDI mass spectrometry profiling has emer...

Varroa destructor is probably the most serious cause of European honey bee (Apis mellifera) losses on a global level. However, the presence of untreated survivor populations in many different regions support the idea of selecting resistant stock. Recently, the European Commission requested a study on the present status of breeding activities regard...

The western honeybee Apis mellifera exhibits a diverse set of adaptations in response to infestations by its most virulent disease-causing agent, the ectoparasitic mite Varroa destructor. In this study, we investigated the effect of honeybee pupae genotype on the expression of four host and parasite traits that are associated with the reproductive...

It was brought to our attention that a preprint version of a refutation to our paper titled “Rapid parallel evolution overcomes global honey bee parasite” was posted through PeerJ recently. This is our formal response to the refutation, which can be found through this link: https://peerj.com/preprints/27938/ Here we have broken down the arguments o...

The mite Varroa destructor is known for causing devastating colony losses in the western honey bee, Apis mellifera. While chemical treatments are currently the norm in many countries, the most sustainable solution against this pest is to select and breed varroa-resistant honey bees. However, this solution is impeded by the difficulty to evaluate th...

Characterising the genetic diversity of populations allows to better understand their demographic history and their adaptation to selective pressures. In honey bees, this characterisation is facilitated by a relatively small genome size, but is hindered by the fact that often the unit of observation and sampling is the colony rather than a single i...

Chemical communication is a fascinating aspect of social insect biology and the honeybee is probably one of the most extensively studied model in chemical ecology. Honeybees use pheromones to communicate between individuals and to regulate the development and social interactions of the colony as well. More than 50 chemical compounds have been ident...

The communication in social insets, particularly honeybees, is regulated by a complex language mediated by chemical signals, mostly pheromones. Those can be highly volatile, with low molecular weights and fast diffusion in air or less volatile, heavier, adsorbed on the surface of the body and passed through direct body contact or during food transf...

Varroa destructor is probably the most serious cause of European honey bee ( Apis mellifera ) losses on a global level. However, the presence of untreated survivor populations in many different regions support the idea of selecting resistant stock. Recently, the European Commission requested a study on the present status of breeding activities rega...

Honeybee is native from Africa, Europe and western Asia and its presence elsewhere in the world is due to human imports. In New Caledonia, importation of Western-Europe M lineage honeybees from France started in the 19th century and these black honeybees were dominant until the late 1980’s when an American foulbrood infestation decimated the coloni...

Co-exposure to pesticides and viruses is likely to occur in honey bee colonies. Pesticides can be present in pollen, nectar, and persist in stored food (honey and bee bread), and viruses can be highly prevalent in honey bee colonies. Therefore, the present study describes the influence of chronic co-exposure to thiamethoxam and Chronic bee paralysi...

The ectoparasitic mite, Varroa destructor, is the most severe biotic threat to honeybees (Apis mellifera) globally, usually causing colony death within a few years without treatments. While it is known that a few A. mellifera populations survive mite infestations by means of natural selection, the possible role of mite adaptations remains unclear....

Compared to the queen or the workers, the biology of honey bee Apis mellifera L. drones is poorly known. Available information on drone activity is based mainly on direct observations during a limited period of time and for a restricted time of the day. Complete registers of the flight activity of honey bee drones are lacking. We studied the activi...

Keywords: Apiculture Beekeeping Forage resource management Adaptive capacity Participatory design Multicriteria assessment A B S T R A C T Beekeeping is a long-standing production of livestock, which currently faces several technical and economic challenges such as high colony losses and highly variable honey yields. While the sustainability of cur...

Small hive beetles (SHBs) are parasites of social bee colonies endemic to sub-Saharan Africa and have become a widespread invasive species. In the new ranges, SHBs can cause damage to apiculture and wild bees. Although the further spread seems inevitable, eradication of new introductions and containment of established ones are nevertheless urgently...