A pragmatic approach to the analysis of diets of generalist predators: the use of next-generation sequencing with no blocking probes

Predicting whether a predator is capable of affecting the dynamics of a prey species in the field implies the analysis of the complete diet of the predator, not simply rates of predation on a target taxon. Here, we employed the Ion Torrent next-generation sequencing technology to investigate the diet of a generalist arthropod predator. A complete dietary analysis requires the use of general primers, but these will also amplify the predator unless suppressed using a blocking probe. However, blocking probes can potentially block other species, particularly if they are phylogenetically close. Here, we aimed to demonstrate that enough prey sequence could be obtained without blocking probes. In communities with many predators, this approach obviates the need to design and test numerous blocking primers, thus making analysis of complex community food webs a viable proposition. We applied this approach to the analysis of predation by the linyphiid spider Oedothorax fuscus in an arable field. W...要预测捕食者在野外是否能够影响猎物种群的动态，需分析捕食者的完整食性，而非仅关注针对特定类群的捕食率。本研究采用离子激流（Ion Torrent）下一代测序技术，对一种广食性节肢动物捕食者的食性展开调查。完整的食性分析需使用通用引物，但通用引物同时也会扩增捕食者自身的DNA，除非通过封闭探针（blocking probe）对其进行抑制。然而，封闭探针有可能同时抑制其他物种的扩增，尤其是在系统发育关系较近的类群中。本研究旨在证明，无需使用封闭探针即可获取足够的猎物序列数据。在包含多种捕食者的群落中，该方法无需设计并测试大量封闭引物，从而使复杂群落食物网的分析成为可行方案。我们将该方法应用于农田中皿蛛科（Linyphiidae）蜘蛛暗色微蛛（Oedothorax fuscus）的捕食行为分析。[原文内容至此截断]