Interactive effect of fungicides and insecticides on the gut microbiome composition and its implication to honey bee health

Apis mellifera has a relatively consistent gut microbial community that is thought to enhance host health and protect against parasites and pathogens. But the gut microbiome can be disrupted by pesticides and in-hive chemicals, putting honey bee health in danger. We used a controlled and fully crossed laboratory experimental design to test the effects of chronic exposure to field-realistic sublethal concentrations of two nicotinic acetylcholine receptor agonist insecticides (nACHRs) namely flupyradifurone (FPF) and sulfoxaflor (Sulf), and a fungicide, azoxystrobin (Azoxy), individually and in combination, on the survival of individual honey bee workers and their gut microbiota (fungal and bacterial diversity and composition).Our findings raise concerns about the long-term impact of the novel insecticides FPF and Sulf, particularly FPF, on pollinator health and recommend a novel methodology for a refined risk assessment that should include the potential effects of agrochemicals on the gut microbiome of bees.

西方蜜蜂（Apis mellifera）拥有相对稳定的肠道微生物群落，该群落被认为可增强宿主健康、抵御寄生虫与病原体。然而，肠道微生物组易受农药及蜂箱内化学物质的干扰，进而威胁蜜蜂的健康。本研究采用可控且完全交叉的实验室实验设计，测试了慢性暴露于田间现实水平亚致死浓度的两种烟碱型乙酰胆碱受体激动剂类杀虫剂（nACHRs，即氟吡呋喃酮（FPF）与氟啶虫胺腈（Sulf））以及杀菌剂嘧菌酯（Azoxy），分别单独施用与复配施用时，对西方蜜蜂工蜂个体存活率及其肠道微生物组（真菌与细菌的多样性及组成）的影响。本研究结果对新型杀虫剂FPF与Sulf，尤其是FPF，对传粉昆虫健康的长期影响引发了担忧，并建议采用全新的研究方法开展精细化风险评估，该评估需纳入农用化学品对蜜蜂肠道微生物组的潜在影响。