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 feeding on smaller life stages). We also found that 2) although predator hunting traits, including web and venom use, are thought to shape predator-prey interaction outcomes, predator identity more strongly influenced our indirect measure of the relative size of predators and prey (predator:prey size ratios) than either of these hunting traits. Our findings indicate that predator body size and species identity are important in shaping trophic interactions in invertebrate food webs and could help predict how anthropogenic biodiversity change will influence terrestrial invertebrates, the earth’s most diverse animal taxonomic group.

Refer to the methods described in the README.txt and the associated manuscript https://doi.org/10.1002/ecy.3634

data.zip includes all data output from sequence merging (via DADA2) and outputs of intermediate cleaning and analysis steps. Raw sequencing data can be found in the GenBank BioProject: PRJNA715709.

The README.txt file contains information on collection methods, contributors, and data table column explanations. 

The dna_predators.zip file in Zenodo contains the same README.txt file and the same data and code used to reproduce all steps from sequence merging to final analyses. This folder also contains an .Rproj (R Project) that enables efficient reproducibility of all R-based analysis steps.

Related dataset: 

Miller-ter Kuile, Ana et al. (2022), Data from: Changes in Invertebrate Food Web Structure Between High- and Low-productivity Environments are Driven by Intermediate but Not Top Predator Diet Shifts, Dryad, Dataset, https://doi.org/10.25349/D9C334