Data from: Can differential nutrient extraction explain property variations in a predatory trap?

Predators exhibit flexible foraging to facilitate taking prey that offer important nutrients. Because trap-building predators have limited control over the prey they encounter, differential nutrient extraction and trap architectural flexibility may be used as a means of prey selection. Here, we tested whether differential nutrient extraction induces flexibility in architecture and stickiness of a spider's web by feeding Nephila pilipes live crickets (CC), live flies (FF), dead crickets with the web stimulated by flies (CD) or dead flies with the web stimulated by crickets (FD). Spiders in the CD group consumed less protein per mass of lipid or carbohydrate, and spiders in the FF group consumed less carbohydrates per mass of protein. Spiders from the CD group built stickier webs that used less silk, whereas spiders in the FF group built webs with more radii, greater catching areas and more silk, compared with other treatments. Our results suggest that differential nutrient extraction is a likely explanation for prey-induced spider web architecture and stickiness variations.捕食者会演化出灵活的觅食策略，以获取能够提供关键营养物质的猎物。由于结网型捕食者对其偶遇的猎物缺乏主动调控能力，因此它们或可通过差异化营养摄取策略与蛛网结构的灵活性来实现猎物选择。本研究以棒络新妇蜘蛛（Nephila pilipes）为实验对象，通过设置四组投喂处理：活蟋蟀组（CC）、活苍蝇组（FF）、经苍蝇刺激蛛网后的死蟋蟀组（CD）以及经蟋蟀刺激蛛网后的死苍蝇组（FD），检验差异化营养摄取是否会诱导蛛网结构与粘性产生可塑性变化。实验结果显示，CD组蜘蛛每单位脂质或碳水化合物摄入对应的蛋白质摄取量更低，FF组蜘蛛每单位蛋白质摄入对应的碳水化合物摄取量更低。相较于其余三组处理，CD组蜘蛛所结蛛网粘性更强且用丝量更少；FF组蜘蛛则构建出辐射丝更多、捕虫面积更大且用丝量更高的蛛网。本研究结果表明，差异化营养摄取或是猎物诱导蛛网结构与粘性产生变异的合理解释。