Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain; Universidad Politécnica de Madrid, 28040 Madrid, Spain.
Dipartimento di Scienze e Tecnologie Agro-Alimentari, Alma Mater Studiorum Università di Bologna, 40127 Bologna, Italy.
Environ Pollut. 2024 Dec 15;363(Pt 1):125129. doi: 10.1016/j.envpol.2024.125129. Epub 2024 Oct 15.
Pollinators are essential for crop productivity. Yet, in agricultural areas, they may be threatened by pesticide exposure. Current pesticide risk assessments predominantly focus on honey bees, with a lack of standardized protocols for solitary bees. This study addresses this gap by developing a long-term oral exposure protocol tailored for O. bicornis. We conducted initial trials to determine optimal container sizes and feeding methods, ensuring high survival rates and accurate syrup consumption measurements. A validation test involving five laboratories was then conducted with the insecticide Flupyradifurone (FPF). Control mortality thresholds were set at ≤ 15% at 10 days. Three laboratories achieved ≤10%, demonstrating the protocol's effectiveness in maintaining healthy test populations. The seasonal timing of experiments influenced control mortality, underscoring the importance of aligning tests with the natural flight period of the population used. Our findings revealed dose-dependent effects of FPF on syrup consumption, showing stimulatory effects at lower concentrations and inhibitory effects at higher ones. The 10-day median lethal daily dose (LDD50) of FPF for O. bicornis (531.92 ng/bee/day) was 3.4-fold lower than that reported for Apis mellifera (1830 ng/bee/day), indicating Osmia's higher susceptibility. Unlike other insecticides, FPF did not exhibit time-reinforced toxicity. This study introduces a robust protocol for chronic pesticide exposure in solitary bees, addressing a critical gap in current risk assessment. Based on its low risk to honey bees and bumblebees, FPF is approved for application during flowering. However, our results suggest that it may threaten Osmia populations under realistic field conditions. Our findings underscore the need for comparative toxicity studies to ensure comprehensive protection of all pollinators and the importance of accounting for long term exposure scenarios in risk assessment. By enhancing our understanding of chronic pesticide effects in solitary bees, our study should contribute to the development of more effective conservation strategies and sustainable agricultural practices.
传粉媒介对于作物生产力至关重要。然而，在农业地区，它们可能会受到农药暴露的威胁。目前的农药风险评估主要集中在蜜蜂上，而对于独居蜂则缺乏标准化的协议。本研究通过为 O. bicornis 开发一种长期口服暴露协议来解决这一差距。我们进行了初步试验，以确定最佳的容器大小和喂养方法，确保高存活率和准确的糖浆消耗测量。然后，涉及五个实验室的杀虫剂 Flupyradifurone (FPF) 验证测试。控制死亡率阈值设定为 10 天内≤15%。三个实验室的死亡率≤10%，证明了该协议在维持健康的试验种群方面的有效性。实验的季节性时间会影响控制死亡率，这突出表明有必要使测试与所用种群的自然飞行期保持一致。我们的研究结果表明，FPF 对糖浆消耗有剂量依赖性影响，在较低浓度下表现出刺激作用，在较高浓度下表现出抑制作用。FPF 对 O. bicornis 的 10 天中值致死每日剂量 (LDD50)（531.92ng/bee/day）比报道的 Apis mellifera（1830ng/bee/day）低 3.4 倍，表明 Osmia 更为敏感。与其他杀虫剂不同，FPF 没有表现出时间强化毒性。本研究引入了一种针对独居蜂慢性农药暴露的强大协议，解决了当前风险评估中的一个关键差距。由于 FPF 对蜜蜂和熊蜂的风险较低，因此已批准在开花期间使用。然而，我们的结果表明，在实际田间条件下，它可能会威胁到 Osmia 种群。我们的研究结果强调需要进行比较毒性研究，以确保对所有传粉媒介进行全面保护，并在风险评估中考虑长期暴露情况。通过增强我们对独居蜂慢性农药影响的理解，我们的研究应该有助于制定更有效的保护策略和可持续农业实践。
