Abstract：
Honey bees (Apis mellifera) have to withstand various environmental stressors alone or in combination in agriculture settings. Plant protection products are applied to achieve high crop yield, but residues of their active substances are frequently detected in bee matrices and could affect honey bee colonies. In addition, intensified agriculture could lead to resource limitation for honey bees. This study aimed to compare the response of full-sized and nucleus colonies to the combined stressors of fungicide exposure and resource limitation. A large-scale field study was conducted simultaneously at five different locations across Germany, starting in spring 2022 and continuing through spring 2023. The fungicide formulation Pictor® Active (active ingredients boscalid and pyraclostrobin) was applied according to label instructions at the maximum recommended rate on oil seed rape crops. Resource limitation was ensured by pollen restriction using a pollen trap and stressor responses were evaluated by assessing colony development, brood development, and core gut microbiome alterations. Furthermore, effects on the plant nectar microbiome were assessed since nectar inhabiting yeast are beneficial for pollination. We showed, that honey bee colonies were able to compensate for the combined stressor effects within six weeks. Nucleus colonies exposed to the combined stressors showed a short-term response with a less favorable brood to bee ratio and reduced colony development in May. No further impacts were observed in either the nucleus colonies or the full-sized colonies from July until the following spring. In addition, no fungicide-dependent differences were found in core gut and nectar microbiomes, and these differences were not distinguishable from local or environmental effects. Therefore, the provision of sufficient resources is important to increase the resilience of honey bees to a combination of stressors.
摘要：
蜜蜂（Apismellifera）必须在农业环境中单独或组合承受各种环境压力。应用植保产品实现作物高产,但是它们的活性物质的残留物经常在蜜蜂基质中检测到，并可能影响蜜蜂菌落。此外,强化农业可能导致蜜蜂资源有限。这项研究旨在比较全尺寸和核菌落对杀菌剂暴露和资源限制的联合应激源的反应。在德国的五个不同地点同时进行了大规模的实地研究，从2022年春季开始，一直持续到2023年春季。根据标签说明以最大推荐的速率将杀真菌剂制剂Pictor®Active(活性成分啶酰菌胺和吡唑氯甾素)施用在油菜籽作物上。通过使用花粉诱捕器限制花粉来确保资源限制，并通过评估菌落发育来评估胁迫源反应。育卵发育，和核心肠道微生物组改变。此外，对植物花蜜微生物组的影响进行了评估，因为花蜜栖息的酵母有利于授粉。我们展示了,蜜蜂群体能够在六周内补偿综合应激源效应。暴露于组合应激源的核菌落显示出短期反应，育龄与蜜蜂的比例较差，并且5月份菌落发育减少。从7月到次年春天，在核菌落或全尺寸菌落中均未观察到进一步的影响。此外,在核心肠道和花蜜微生物组中没有发现杀菌剂依赖性的差异，这些差异与当地或环境影响没有区别。因此,提供足够的资源对于增加蜜蜂对压力源的抵御能力很重要。
