Data from: Neonicotinoid pesticides and nutritional stress synergistically reduce survival in honey bees

The honey bee (Apis mellifera L.) is a major pollinator whose health is of global concern. Declines in honey bee health are related to multiple factors, including resource quality and pesticide contamination. Intensive agricultural areas with crop monocultures potentially reduce the quality and quantity of available nutrients and expose bee foragers to pesticides. However, there is, to date, no evidence for synergistic effects between pesticides and nutritional stress in animals. The neonicotinoids clothianidin (CLO) and thiamethoxam (TMX) are common systemic pesticides that are used worldwide and found in nectar and pollen. We therefore tested if nutritional stress (limited access to nectar, and access to nectar with low sugar concentrations) and sublethal, field-realistic acute exposures to two neonicotinoids (CLO and TMX at 1/5 and 1/25 of LD50) could alter bee survival, food consumption, and hemolymph sugar levels. Bee survival was synergistically reduced by the combination of poor nutrition and pesticide exposure (-50%). Nutritional and pesticide stressors reduced also food consumption (-48%) and hemolymph levels of glucose (-60%) and trehalose (-27%). Our results provide the first demonstration that field-realistic nutritional stress and pesticide exposure can synergistically interact and cause significant harm to animal survival. These findings have implications for current pesticide risk-assessment procedures and pollinator protection.

西方蜜蜂（Apis mellifera L.）是一类重要的传粉昆虫，其健康状况备受全球关注。蜜蜂健康状况的衰退与多重因素相关，涵盖蜜源资源质量与农药污染两大方面。实施作物单一种植的集约化农业区域，不仅可能降低可获取营养的质量与数量，还会使蜜蜂觅食者暴露于农药环境中。但截至目前，尚无证据表明农药与营养胁迫在动物体内存在协同交互效应。新烟碱类（neonicotinoids）杀虫剂噻虫胺（CLO）与噻虫嗪（TMX）是全球广泛应用的常见内吸性农药，可在花蜜与花粉中被检出。为此，本研究开展了相关测试，旨在探究营养胁迫（花蜜获取受限以及低糖浓度花蜜摄入）与亚致死、符合田间实际暴露水平的急性暴露于两种新烟碱类农药（噻虫胺和噻虫嗪，剂量分别为半致死剂量LD50的1/5和1/25）是否会对蜜蜂的存活率、食物消耗量以及血淋巴糖水平产生影响。结果显示，营养不良与农药暴露的联合作用可使蜜蜂存活率协同降低50%。营养与农药胁迫同时还会使食物消耗量降低48%，血淋巴中的葡萄糖（glucose）与海藻糖（trehalose）水平分别下降60%与27%。本研究首次证实，符合田间实际场景的营养胁迫与农药暴露可产生协同交互作用，并对动物存活率造成显著危害。上述研究结果对现行农药风险评估流程及传粉昆虫保护工作具有重要参考价值。