70 research outputs found

    Deformed wing virus is not related to honey bees' aggressiveness

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    Guards of Cyprian honey bee colonies, Apis mellifera cypria, display a great defensive behaviour against hornets' attacks. The deformed wing virus (DWV) and the kakugo virus (KV) genomes are very similar, but unlike KV, the presence of DWV is not related to honey bees' aggressiveness. This discrepancy is further discussed

    Risk assessment of pesticides and other stressors in bees: Principles, data gaps and perspectives from the European Food Safety Authority

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    Current approaches to risk assessment in bees do not take into account co-exposures from multiple stressors. The European Food Safety Authority (EFSA) is deploying resources and efforts to move towards a holistic risk assessment approach of multiple stressors in bees. This paper describes the general principles of pesticide risk assessment in bees, including recent developments at EFSA dealing with risk assessment of single and multiple pesticide residues and biological hazards. The EFSA Guidance Document on the risk assessment of plant protection products in bees highlights the need for the inclusion of an uncertainty analysis, other routes of exposures and multiple stressors such as chemical mixtures and biological agents. The EFSA risk assessment on the survival, spread and establishment of the small hive beetle, Aethina tumida, an invasive alien species, is provided with potential insights for other bee pests such as the Asian hornet, Vespa velutina. Furthermore, data gaps are identified at each step of the risk assessment, and recommendations are made for future research that could be supported under the framework of Horizon 2020. Finally, the recent work conducted at EFSA is presented, under the overarching MUST-B project ("EU efforts towards the development of a holistic approach for the risk assessment on MUltiple STressors in Bees") comprising a toolbox for harmonised data collection under field conditions and a mechanistic model to assess effects from pesticides and other stressors such as biological agents and beekeeping management practices, at the colony level and in a spatially complex landscape. Future perspectives at EFSA include the development of a data model to collate high quality data to calibrate and validate the model to be used as a regulatory tool. Finally, the evidence collected within the framework of MUST-B will support EFSA's activities on the development of a holistic approach to the risk assessment of multiple stressors in bees. In conclusion, EFSA calls for collaborative action at the EU level to establish a common and open access database to serve multiple purposes and different stakeholders

    Analysis of background variability of honey bee colony size

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    In the context of the definition of specific protection goals for bees, risk managers asked EFSA to provide scientific background to support them in their decision‐making process about what needs to be protected and to what extent. The risk managers indicated that the derivation of a threshold of acceptable effects on colony size based on their variability was the preferred option for honey bees. This approach assumes that when evaluating a pesticide, the magnitude of acceptable effects should be set within the range of the background variability of colonies not exposed to pesticides. In this report EFSA used the BEEHAVE model to assess background variability of colony size in 19 EU environmental scenarios covering a range of geographical, climatic and beekeeping conditions. A comparison was made between the model outcome and the measurements performed on control groups of experimental field studies. The analysis of the background variability presented in this document should support risk managers in defining a threshold for colony size reduction that is considered acceptable

    High accuracy monitoring of honey bee colony development by a quantitative method

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    Honey bees are key insect pollinators, providing important economic and ecological value for human beings and ecosystems. This has triggered the development of several monitoring methods for assessing the temporal development of colony size, food storage, brood and pathogens. Nonetheless, most of these methods are based on visual assessments that are observer-dependent and prone to bias. Furthermore, the impact on colony development (invasiveness), as well as accuracy, were rarely considered when implementing new methods. In this study, we present and test a novel accurate and observer-independent method for honey bee colony assessment, capable of being fully standardized. Honey bee colony size is quantified by assessing the weight of adult bees, while brood and provision are assessed by taking photos and conducting image analysis of the combs with the image analysis software DeepbeeVR . The invasiveness and accuracy of the method were investigated using field data from two experimental apiaries in Portugal, comparing results from test and control colonies. At the end of each field experiment, most of the tested colonies had the same colony size, brood levels and honey production as the control colonies. Nonetheless, continuous weight data indicated some disturbance in tested colonies in the first year of monitoring. The overall accuracy of the image analysis software was improved by training, indicating that it is possible to adapt the software to local conditions. We conclude that the use of this fully quantitative method offers a more accurate alternative to classic visual colony assessments, with negligible impact on colony development.This work was supported by European Food Safety Authority under grant OC/EFSA/SCER/2017/02; FCT provided financial support by national funds (FCT/MCTES) to CFE (UIDB/04004/2020) and CIMO (UIDB/00690/2020); NC was financed by FCT under PhD grant SFRH/BD/133352/2017; YLD by DCE (Danish Centre for Environment and Energy) under grant 21628-82105.info:eu-repo/semantics/publishedVersio

    Modes of honeybees exposure to systemic insecticides: estimated amounts of contaminated pollen and nectar consumed by different categories of bees

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    International audienceThe hazard posed to honeybees by systemic insecticides is determined by toxicity tests that are designed to study the effects of insecticides applied on the aerial parts of plants, but are not adapted to systemic substances used as soil or seed treatments. Based on the available data found in the literature, this paper proposes modes of honeybees exposure to systemic insecticides by estimating their pollen and nectar consumption. Estimates are given for larvae and for the categories of adults which consume the highest amounts of - pollen, the nurse bees, and - nectar, the wax-producing bees, the brood attending bees, the winter bees, and the foraging bees. As a case study, we illustrate these estimates with the example of imidacloprid because its concentrations in sunflower nectar and in sunflower and maize pollens of seed-dressed plants have been precisely determined, and because its levels of lethal, sublethal, acute, and chronic toxicities have been extensively investigated
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