Predator-prey Interactions of Terrestrial Invertebrates are Determined by Predator Body Size and Species Identity

Predator-prey interactions shape ecosystem and can help maintain biodiversity. However, for many of the earth’s most biodiverse and abundant organisms, including terrestrial arthropods, these interactions are difficult or impossible to observe directly with traditional approaches. Based on previous theory, it is likely that predator-prey interactions for these organisms are shaped by a combination of predator traits, including body size and species-specific hunting strategies. In this study, we combined diet DNA metabarcoding data of 173 individual invertebrate predators from nine species (a total of 305 predator-prey interactions) with an extensive community body size dataset of a well-described invertebrate community to explore how predator traits and identity shape interactions. We found that 1) mean size of prey families in the field usually scaled with predator size, with species-specific variation to a general size scaling relationship (exceptions likely indicating scavenging or f...捕食者-猎物互作塑造生态系统格局，并有助于维持生物多样性。然而，对于地球上生物多样性最为丰富、种群数量最为庞大的诸多类群而言，包括陆生节肢动物在内，采用传统研究方法难以甚至无法直接观测这类互作过程。基于已有理论推测，这类生物的捕食者-猎物互作可能由捕食者的多种性状共同调控，包括体型大小以及物种特有的捕猎策略。本研究整合了来自9个物种的173只无脊椎动物捕食者的食谱DNA元条形码（diet DNA metabarcoding）数据（共计305组捕食者-猎物互作记录），并结合某一特征明确的无脊椎动物群落的大规模体型数据集，以探究捕食者性状及其物种身份如何调控互作过程。研究结果显示：1）野外环境中猎物科的平均体型通常随捕食者体型呈现缩放关系，且存在物种特异性的偏离普遍体型缩放规律的情况（异常值大概率代表食腐行为或f...