Agroecology and Environment, Agroscope, Zürich, Switzerland.
UR406 Abeilles and Environnement, Site Agroparc, INRAE, Avignon, France.
Proc Biol Sci. 2022 Oct 12;289(1984):20221013. doi: 10.1098/rspb.2022.1013.
Pesticide exposure and food stress are major threats to bees, but their potential synergistic impacts under field-realistic conditions remain poorly understood and are not considered in current pesticide risk assessments. We conducted a semi-field experiment to examine the single and interactive effects of the novel insecticide flupyradifurone (FPF) and nutritional stress on fitness proxies in the solitary bee . Individually marked bees were released into flight cages with monocultures of buckwheat, wild mustard or purple tansy, which were assigned to an insecticide treatment (FPF or control) in a crossed design. Nutritional stress, which was high in bees foraging on buckwheat, intermediate on wild mustard and low on purple tansy, modulated the impact of insecticide exposure. Within the first day after application of FPF, mortality of bees feeding on buckwheat was 29 times higher compared with control treatments, while mortality of FPF exposed and control bees was similar in the other two plant species. Moreover, we found negative synergistic impacts of FPF and nutritional stress on offspring production, flight activity, flight duration and flower visitation frequency. These results reveal that environmental policies and risk assessment schemes that ignore interactions among anthropogenic stressors will fail to adequately protect bees and the pollination services they provide.
农药暴露和食物压力是蜜蜂面临的主要威胁，但在田间实际条件下，它们的潜在协同影响仍知之甚少，而且在当前的农药风险评估中并未考虑这些因素。我们进行了一项半田间实验，以检验新型杀虫剂氟氯吡啶酯（FPF）和营养胁迫对独居蜜蜂适应度指标的单一和交互影响。单独标记的蜜蜂被释放到飞行笼中，里面有荞麦、野生芥菜或紫甘菊的单一种植，这些植物采用交叉设计，分配到杀虫剂处理（FPF 或对照）中。在荞麦上觅食的蜜蜂营养胁迫很高，在野生芥菜上中等，在紫甘菊上低，这种营养胁迫调节了杀虫剂暴露的影响。在施用 FPF 的第一天后，在荞麦上觅食的蜜蜂死亡率比对照处理高 29 倍，而在其他两种植物上，FPF 暴露和对照蜜蜂的死亡率相似。此外，我们发现 FPF 和营养胁迫对后代产量、飞行活动、飞行持续时间和花朵访问频率有负协同影响。这些结果表明，忽视人为胁迫因素之间相互作用的环境政策和风险评估方案将无法充分保护蜜蜂及其提供的授粉服务。
