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...