European Lepidoptera-Plant Associations: A Species-Level Interaction Matrix.

Documenting plant-herbivore interactions at broad spatial scales is crucial for understanding the ecological and evolutionary processes that shape biodiversity. Here I present a continental-scale interaction matrix encompassing 5152 Lepidoptera species and 3275 vascular plant species across Europe. The dataset compiles records from published literature, monographs, online repositories, and gray sources, with all taxa standardized to current classifications. By resolving associations at the species level, this resource provides a robust basis for investigating host specialization, network structure, and patterns of herbivore diversity in biogeographic and phylogenetic contexts. In addition to supporting fundamental research, the matrix offers applied value for conservation biology-for example, by identifying keystone host plants that sustain diverse herbivore assemblages and by assessing the vulnerability of insect communities to host loss under global change. The dataset is openly available in a machine-readable format under a CC-BY 4.0 license, ensuring transparency, reproducibility, and long-term accessibility for ecological and evolutionary studies.