Climate change and human-aided introductions are rapidly altering the ranges of most organisms, and novel trophic interactions have developed between organisms that previously did not co-occur. I explored novel interactions between native herbivores and non-native plants in order to understand the mechanisms that underlie novel host use and to build predictive models that anticipate novel food webs. I found that different herbivores responded to different non-native plant traits, but that phylogenetic similarity between the novel host and a local native host was typically a good predictor of host-use. Using information about native food webs and plant phylogeny, I was able to accurately predict the moth and butterfly communities on non-native plants introduced to central Europe. At a broad scale, novel herbivore-plant interactions are predictable based on plant relationships and traits, even though the mechanisms governing each interaction may differ