Data from: Climate and regional plant richness drive diet specialization in butterfly caterpillars

Studies of coevolution, ecosystem processes, and latitudinal diversity
gradients are improved by understanding variation in resource
specialization. Insect herbivory is one of the most ubiquitous terrestrial
ecological associations, and is important for understanding the evolution
of both plants and insects, yet the processes underlying global variation
in diet breadth remain poorly understood. Here, we use global datasets of
butterfly and plant distributions to investigate the patterns and drivers
of butterfly larval diet breadth. Diet breadth showed a negative
relationship with plant family richness, but this was offset by a direct
effect of temperature acting in the opposite direction. Islands generally
harbor species with broader diets, but islands with higher endemism had
narrower diets than average. Our study provides a global baseline for
understanding how plant and herbivore interactions structure ecological
communities in the face of global environmental changes.