To determine the potential long-term risks associated with continual use of pesticides, we investigated (1) whether short-term exposure (48 h) of first generation (1G) Scapholeberis kingi to two acetylcholinesterase-inhibitor insecticides, pyraclofos and pirimicarb, would alter acetylcholinesterase-inhibitor sensitivity (based on immobility) in the second generation (2G), (2) whether acetylcholinesterase (AChE) activity-levels could be related to any observed change in sensitivity, and (3) whether intrinsic growth rates (r) in field cladocerans could vary between generations. We collected field-clone populations of different sensitivities from four sites in an agricultural area. Neonates (< 24 h old) were selected after insecticidal exposure for 48 h, then cultured without insecticide to obtain second-generation neonates. Based on the 48 h EC₅₀ values, 2G neonates in the majority of the selected clones were more sensitive to the insecticides compared to the control groups. Changes in sensitivity could not be explained by AChE activity in the 2G. Although the r values decreased in few selected clones, these values recovered in the 2G suggesting that they could rapidly adapt to insecticidal exposure at the population level. The findings from our study can contribute to a better understanding in the potential risks of insecticides to aquatic organisms.

中文翻译：

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增加的乙酰胆碱酯酶抑制剂敏感性，作为对Scapholeberis kingi中短期乙酰胆碱酯酶抑制剂暴露的代际反应

要确定的长期风险与连续使用杀虫剂相关的潜力，我们调查（1）第一代（1G）的短期暴露（48小时）是否Scapholeberis kingi两个乙酰胆碱酯酶抑制剂杀虫剂，吡唑硫磷和抗蚜威，将改变第二代（2G）中的乙酰胆碱酯酶抑制剂敏感性（基于固定性），（2）乙酰胆碱酯酶（AChE）活性水平是否与所观察到的敏感性变化有关，以及（3）内在增长率（r）锁骨在世代之间可能有所不同。我们从一个农业地区的四个地点收集了不同敏感性的野外克隆种群。在接触杀虫剂48小时后选择新生儿（<24小时），然后在不使用杀虫剂的情况下进行培养，以获得第二代新生儿。根据48 h EC ₅₀值，与对照组相比，大多数选定克隆中的2G新生儿对杀虫剂更为敏感。灵敏度的变化无法用2G中的AChE活性来解释。虽然r在少数几个选定的克隆中，该值下降，这些值在2G中恢复，表明它们可以快速适应种群水平的杀虫暴露。我们的研究结果有助于更好地了解杀虫剂对水生生物的潜在风险。