I.U.I. CIBIO, Universidad de Alicante, Alicante, E-03080, Spain.
Departamento de Fisiología, Genética y Microbiología. Universidad de Alicante, Alicante, E-03080, Spain.
Sci Rep. 2018 Oct 5;8(1):14885. doi: 10.1038/s41598-018-33241-0.
Among macrocyclic lactones (ML), ivermectin (IVM) and moxidectin (MOX) potentially affect all Ecdysozoan species, with dung beetles being particularly sensitive. The comparative effects of IVM and MOX on adult dung beetles were assessed for the first time to determine both the physiological sub-lethal symptoms and pre-lethal consequences. Inhibition of antennal response and ataxia were tested as two intuitive and ecologically relevant parameters by obtaining the lowest observed effect concentration (LOEC) values and interpolating other relevant toxicity thresholds derived from concentration-response curves (IC, as the concentration of each ML where the antennal response is inhibited by half; and pLC, as the quantity of ingested ML where partial paralysis was observed by half of treated individuals) from concentration-response curves. Both sub-lethal and pre-lethal symptoms obtained in this study coincided in that IVM was six times more toxic than MOX for adult dung beetles. Values of LOEC, IC and pLC obtained for IVM and MOX evaluated in an environmental context indicate that MOX, despite needing more time for tis elimination in the faeces, would be twice as harmful to dung beetles as IVM. This approach will be valuable to clarify the real impact of MLs on dung beetle health and to avoid the subsequent environmental consequences.
在大环内酯类（ML）中，伊维菌素（IVM）和莫昔克丁（MOX）可能会影响所有节肢动物，而蜣螂对其特别敏感。本研究首次评估了 IVM 和 MOX 对成年蜣螂的比较影响，以确定其生理亚致死症状和致死前后果。通过获得最低观察效应浓度（LOEC）值并从浓度-反应曲线（IC，即对半抑制触角反应的 ML 浓度；和 pLC，即半处理个体观察到部分麻痹的摄入 ML 量）中插值其他相关毒性阈值，测试了触角反应抑制和共济失调作为两种直观且具有生态相关性的参数。本研究中获得的亚致死和致死前症状一致，即 IVM 对成年蜣螂的毒性是 MOX 的六倍。在环境背景下评估的 IVM 和 MOX 的 LOEC、IC 和 pLC 值表明，尽管 MOX 在粪便中消除需要更多时间，但对蜣螂的危害将是 IVM 的两倍。这种方法将有助于阐明 ML 对蜣螂健康的实际影响，并避免随后的环境后果。
