The neonicotinoid imidacloprid and the herbicide diuron are long‐lived pesticides commonly detected in European rivers. Both have lethal as well as sublethal effects on aquatic invertebrates dwelling in streambeds. Here, we performed lethality tests of imidacloprid and diuron on seven species of widespread, free‐living nematodes and the model organism Caenorhabditis elegans. Our results indicated that nematodes were relatively tolerant to both pesticides, and only two species (Diploscapter coronatus and Plectus opisthocirculus) showed mortality at high nominal concentrations of imidacloprid (119 mg/L) and diuron (33 mg/L). The changes observed in nematode community structure after imidacloprid and diuron exposure may have been related to trade‐offs between sensitivity to toxicants and changes in competitive abilities of the species. While the former can be tested using single‐species tests, we recommend that the latter be tested in further experiments using multispecies communities. Our results suggest that the presence of these pesticides could favor nematodes over other meiofaunal groups found in freshwater sediments.

中文翻译：

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自由生活线虫物种对吡虫啉和敌草隆的耐受性

新烟碱类吡虫啉和除草剂敌草隆是欧洲河流中常见的长效杀虫剂。两者都对居住在河床中的水生无脊椎动物具有致死和亚致死作用。在这里，我们对七种广泛分布的自由生活线虫和模式生物秀丽隐杆线虫进行了吡虫啉和敌草隆的致死率测试。我们的结果表明，线虫对这两种杀虫剂都具有相对耐受性，只有两种物种（Diploscapter coronatus 和 Plectus opisthocirculus）在吡虫啉 (119 mg/L) 和敌草隆 (33 mg/L) 的高标称浓度下表现出死亡率。在吡虫啉和敌草隆暴露后观察到的线虫群落结构变化可能与对毒物的敏感性和物种竞争能力变化之间的权衡有关。虽然前者可以使用单物种测试进行测试，但我们建议在使用多物种群落的进一步实验中测试后者。我们的结果表明，与淡水沉积物中发现的其他小型动物群相比，这些杀虫剂的存在可能有利于线虫。