Complex landscapes, complex diets: DNA metabarcoding reveals lady beetle prey richness increase with landcover diversity

Understanding the capacity of mobile organisms such as insects to utilize resources across different patches in a landscape can reveal strategies for their conservation. Past research suggests that higher levels of non-crop habitat or landcover diversity in agricultural regions typically benefits generalist predators who can fortify their diets with prey from multiple adjacent habitats. For some taxa such as lady beetles (Coccinellidae), dietary diversity is associated with improved fitness, but foraging patterns in real landscapes are hard to measure. We used a DNA metabarcoding approach to explore how the presence and taxonomic richness of arthropod prey in lady beetle diets varied by local habitat (crop vs. non-crop) and landscape complexity (non-crop habitat and landcover diversity in a 250 m radius). We collected over 500 individual lady beetles from a range of landscapes in 2019 and 2021 in southern Wisconsin (USA), performed whole-body DNA extractions, amplified arthropod DNA usi..., , # Complex landscapes, complex diets: DNA metabarcoding reveals lady beetle prey richness increase with landcover diversity ## Overview This repository contains the data and R analysis code associated with: Iuliano B, Gratton C (2026). Complex landscapes, complex diets: DNA metabarcoding reveals lady beetle prey richness increases with landcover diversity. *Ecological Applications*. The study used DNA metabarcoding of gut contents to characterize the diets of eight lady beetle (Coccinellidae) species collected across agricultural and semi-natural habitats in Wisconsin, USA (2019 and 2021). We examined how local habitat type and landscape composition and diversity relate to prey detection rates and prey taxon richness. --- ## Files included ### Code * **`Iuliano_EA_2026.Rproj `**— RStudio project file. Opening this file in RStudio will automatically set the working directory to the project folder, ensuring all relative file paths in the analysis script resolve correctly. * **`Iuli..., ,