Few keystone plant genera support the majority of Lepidoptera species.

Functional food webs are essential for the successful conservation of ecological communities, and in terrestrial systems, food webs are built on a foundation of coevolved interactions between plants and their consumers. Here, we collate published data on host plant ranges and associated host plant-Lepidoptera interactions from across the contiguous United States and demonstrate that among ecosystems, distributions of plant-herbivore interactions are consistently skewed, with a small percentage of plant genera supporting the majority of Lepidoptera. Plant identities critical for retaining interaction diversity are similar and independent of geography. Given the importance of Lepidoptera to food webs and ecosystem function, efficient and effective restoration of degraded landscapes depends on the inclusion of such 'keystone' plants. Not all plants are equally able to support native insects. Here, the authors use data on interactions among >12,000 Lepidoptera species and >2000 plant genera across the United States, showing that few plant genera host the majority of Lepidoptera species; this information is used to suggest priorities for plant restoration. [ABSTRACT FROM AUTHOR]