Environmental degradation of rivers in agricultural landscapes is typically caused by multiple co-occurring stressors, but how interactions among stressors affect freshwater ecosystems is poorly understood. Therefore, we investigated the sensitivity and specificity of several measures of benthic macroinvertebrate community response to the individual and combined effects of the pesticide sulfoxaflor (SFX), increased sand sedimentation and elevated nutrients using outdoor recirculating mesocosms. Among the single stressor treatments, nutrients had no observable impact and sand only affected one community response measure compared to controls. High SFX levels had the largest effects on benthic macroinvertebrate communities, negatively affecting six of seven macroinvertebrate response measures. Sulfoxaflor had similar adverse effects on biota when in combination with sand and nutrients in the multi-stressor treatment, suggesting that generally SFX has overwhelming and pervasive effects irrespective of the presence of the other stressors. In contrast to SFX, elevated nutrients had no detectable effect on macroinvertebrate communities, likely as a consequence of nutrients being rapidly taken up by bacteria rather than by benthic algae. Elevated sand sedimentation increased the negative effects of SFX on sediment sensitive taxa, but generally had limited biological effects. This was despite the levels of sedimentation in our treatments being at concentrations that have caused large impacts in other studies. This research points to direct and rapid toxic effects of SFX on stream macroinvertebrates, contrasting with effects of the other stressors. This study emphasises that pesticide effects could be misattributed to other common freshwater stressors, potentially focussing restoration actions on a stressor of lesser importance.

农业景观中河流的环境退化通常是由多种共同发生的压力因素引起的，但人们对压力因素之间的相互作用如何影响淡水生态系统知之甚少。因此，我们研究了底栖大型无脊椎动物群落对杀虫剂氟啶虫胺 (SFX) 的个体效应和综合效应、使用室外再循环微生态系统增加的沙子沉降和增加的养分的几种措施的敏感性和特异性。在单一压力源处理中，与对照相比，营养素没有可观察到的影响，而沙子仅影响一种社区反应措施。高 SFX 水平对底栖大型无脊椎动物群落的影响最大，对七种大型无脊椎动物响应措施中的六种产生负面影响。当在多压力源处理中与沙子和营养物结合使用时，磺胺氟嘧啶对生物群具有类似的不利影响，这表明无论是否存在其他压力源，SFX 通常具有压倒性和普遍性的影响。与 SFX 相比，升高的营养物质对大型无脊椎动物群落没有可检测到的影响，这可能是由于营养物质被细菌而不是底栖藻类迅速吸收的结果。升高的砂沉积增加了 SFX 对沉积敏感类群的负面影响，但通常具有有限的生物效应。尽管在我们的处理中沉淀水平的浓度对其他研究产生了巨大影响。这项研究指出了 SFX 对流大型无脊椎动物的直接和快速的毒性作用，与其他压力源的影响形成对比。这项研究强调，杀虫剂的影响可能会被错误地归因于其他常见的淡水压力因素，从而可能将恢复行动的重点放在重要性较低的压力因素上。