Institute for Environmental Sciences, University of Koblenz-Landau, Fortstrasse 7, 76829, Landau, Germany,
Arch Environ Contam Toxicol. 2012 Jul;63(1):77-85. doi: 10.1007/s00244-011-9743-2. Epub 2012 Jan 6.
Invertebrate communities of lentic habitats comprise, amongst others, the crustacean Asellus aquaticus (Isopoda) and the turbellarian Dendrocoelum lacteum (Tricladida). Because D. lacteum preferentially preys on A. aquaticus, contaminants introduced into the aquatic environment may affect this predator-prey interaction, finally influencing the performance of the predator. However, no studies investigating implications of organic pollutants on this food web subsystem currently exist. Hence, the present study assessed short-term implications of pesticides with different modes of action, namely, the triazole fungicide tebuconazole and the pyrethroid insecticide lambda-cyhalothrin, during a 72 h trial. The experiments for tebuconazole showed a statistically significant decrease in predatory success of D. lacteum. Lambda-cyhalothrin, in contrast, increased predation success by 40%, which is, however, not statistically significant. Both the decrease and the increase in predation seemed to be primarily driven by an altered activity of the prey A. aquaticus. This may be hypothesized because any shift in the prey's activity influenced its probability to stick to mucus, a viscous substance released by D. lacteum, or to encounter the predator directly.
淡水生境的无脊椎动物群落包括甲壳类动物水生虱（等足目）和扁形动物乳状肾虫（三肠目）。由于乳状肾虫优先捕食水生虱，因此引入水生环境的污染物可能会影响这种捕食者-猎物的相互作用，最终影响捕食者的表现。然而，目前尚无研究调查有机污染物对这种食物网亚系统的影响。因此，本研究在 72 小时的试验中评估了不同作用模式的农药（即三唑类杀菌剂戊唑醇和拟除虫菊酯类杀虫剂氯氰菊酯）的短期影响。戊唑醇的实验显示，乳状肾虫的捕食成功率有统计学意义的下降。相比之下，氯氰菊酯增加了 40%的捕食成功率，但这并不具有统计学意义。捕食的减少和增加似乎主要是由猎物水生虱活性的改变驱动的。这可以假设，因为猎物活动的任何变化都会影响其附着在粘液上的可能性，粘液是乳状肾虫释放的粘性物质，或者直接与捕食者相遇的可能性。
