Honey bees are crucial pollinators for agricultural crops but are threatened by a multitude of stressors including exposure to pesticides. Linking our understanding of how pesticides affect individual bees to colony-level responses is challenging because colonies show emergent properties based on complex internal processes and interactions among individual bees. Agent-based models that simulate honey bee colony dynamics may be a tool for scaling between individual and colony effects of a pesticide. The U.S. Environmental Protection Agency (USEPA) and U.S. Department of Agriculture (USDA) are developing the VarroaPop + Pesticide model, which simulates the dynamics of honey bee colonies and how they respond to multiple stressors, including weather, Varroa mites, and pesticides. To evaluate this model, we used Approximate Bayesian Computation to fit field data from an empirical study where honey bee colonies were fed the insecticide clothianidin. This allowed us to reproduce colony feeding study data by simulating colony demography and mortality from ingestion of contaminated food. We found that VarroaPop + Pesticide was able to fit general trends in colony population size and structure and reproduce colony declines from increasing clothianidin exposure. The model underestimated adverse effects at low exposure (36 µg/kg), however, and overestimated recovery at the highest exposure level (140 µg/kg), for the adult and pupa endpoints, suggesting that mechanisms besides oral toxicity-induced mortality may have played a role in colony declines. The VarroaPop + Pesticide model estimates an adult oral LD₅₀ of 18.9 ng/bee (95% CI 10.1–32.6) based on the simulated feeding study data, which falls just above the 95% confidence intervals of values observed in laboratory toxicology studies on individual bees. Overall, our results demonstrate a novel method for analyzing colony-level data on pesticide effects on bees and making inferences on pesticide toxicity to individual bees.

中文翻译：

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使用蜂群模型和贝叶斯推理从实地喂养研究中推断农药对蜜蜂的毒性


蜜蜂是农作物的重要传粉媒介，但受到多种压力源的威胁，包括接触农药。将我们对杀虫剂如何影响个体蜜蜂的理解与蜂群水平的反应联系起来是具有挑战性的，因为蜂群表现出基于复杂的内部过程和个体蜜蜂之间的相互作用的新兴特性。模拟蜜蜂群体动态的基于代理的模型可能是衡量农药对个体和群体影响的工具。美国环境保护署 (USEPA) 和美国农业部 (USDA) 正在开发 VarroaPop + Pesticide 模型，该模型模拟蜂群的动态以及它们如何响应多种压力源，包括天气、瓦螨和杀虫剂。为了评估该模型，我们使用近似贝叶斯计算来拟合一项实证研究中的现场数据，该研究中蜜蜂群体被喂食了杀虫剂噻虫胺。这使我们能够通过模拟群体人口统计和摄入受污染食物造成的死亡率来重现群体喂养研究数据。我们发现 VarroaPop + Pesticide 能够适应菌落种群规模和结构的总体趋势，并再现因增加噻虫胺暴露而导致的菌落衰退。然而，对于成虫和蛹终点，该模型低估了低暴露水平（36 µg/kg）下的不良影响，高估了最高暴露水平（140 µg/kg）下的恢复，这表明除了口服毒性引起的死亡之外，其他机制可能也有影响。在群体衰退中发挥了作用。 VarroaPop + 农药模型估计成人口服 LD ₅₀为 18.9 ng/蜜蜂（95% CI 10.1-32。6) 基于模拟喂养研究数据，该数据略高于实验室毒理学研究中对个体蜜蜂观察到的值的 95% 置信区间。总的来说，我们的结果展示了一种新方法，可以分析农药对蜜蜂影响的群体水平数据，并推断农药对蜜蜂个体的毒性。