Alterra, The Netherlands.
Environ Toxicol Chem. 2009 Oct;28(10):2191-205. doi: 10.1897/09-010.1.
The long-term response, including recovery, of aquatic macroinvertebrates to short-term insecticide exposure may be affected by the presence of uncontaminated refuges in the stressed ecosystem. Experimental ditches were used to study the influence of non-sprayed ditch sections regarding the ecotoxicological effects on and the recovery of macroinvertebrates following treatment with the insecticide lufenuron. The treatment regimes differed in the proportion of the ditch (0, 33, 67, and 100% of surface area) that was sprayed to reach a lufenuron concentration of 3 microg/L in the water column of the sprayed ditch section. The magnitude and duration of effects on macroinvertebrates, and on arthropods in particular, were higher when a larger proportion of the ditch was treated. Initially, more pronounced responses were observed for bivoltine and multivoltine insects and macrocrustaceans than for univoltine and semivoltine arthropods. Most macroinvertebrate arthropods showed delayed responses, with maximum treatment-related effects observed two to six weeks after lufenuron application. This latency of effects can be explained by the mode of action of lufenuron, involving inhibition of chitin synthesis, which affects arthropod molting and metamorphosis. The observed effects were short-lived only in those ditches where 33% of the surface area was sprayed. In the ditches where 67 and 100% of the surface area was sprayed, some insects and macrocrustaceans showed long-term effects. In the 100% sprayed ditches in particular, the treatment-related reduction in arthropods resulted in indirect effects, such as an increase in snails, and later in an increase in the ephemeropteran Cloeon dipterum, probably because of an increase in periphyton, and release from competition and predation. Effects that are most likely indirect also were observed for Oligochaeta, Hirudinea, and the flatworm Mesostoma sp.
水生大型无脊椎动物对短期杀虫剂暴露的长期反应（包括恢复）可能受到受胁迫生态系统中未受污染避难所存在的影响。实验沟渠用于研究未喷洒沟渠部分对生态毒理学效应的影响，以及在使用杀虫剂 lufenuron 处理后大型无脊椎动物的恢复情况。处理方案的不同之处在于，喷洒沟渠的表面面积比例（0、33、67 和 100%）不同，以使喷洒沟渠部分的水层中 lufenuron 浓度达到 3 微克/升。当更大比例的沟渠被处理时，对大型无脊椎动物，特别是节肢动物的影响的幅度和持续时间更大。最初，双（多）代昆虫和大型甲壳类动物比单（半）代节肢动物表现出更明显的反应。大多数大型无脊椎动物节肢动物表现出延迟反应，在 lufenuron 应用后两到六周观察到最大的与处理相关的影响。这种效应的潜伏期可以用 lufenuron 的作用模式来解释，它涉及到几丁质合成的抑制，这影响了节肢动物的蜕皮和变态。只有在喷洒面积为 33%的沟渠中，观察到的效应才是短暂的。在喷洒面积为 67%和 100%的沟渠中，一些昆虫和大型甲壳类动物表现出长期效应。特别是在 100%喷洒的沟渠中，与处理相关的节肢动物减少导致间接影响，例如蜗牛的增加，后来蜉蝣类 Cloeon dipterum 的增加，可能是由于附着生物的增加，以及竞争和捕食的释放。寡毛纲、蛭纲和扁形动物 Mesostoma sp. 也观察到了最有可能是间接的效应。
