Ranking lepidopteran use of native versus introduced ornamental plants

Background/Question/Methods In light of the wide-scale replacement of native plants in North America with introduced, invasive species and non-invasive ornamental plants that evolved elsewhere, we compared the value of native and introduced plants in terms of their ability to serve as host plants for Lepidoptera. Insect herbivores such as Lepidoptera larvae are critically important components of terrestrial food webs and any reduction in their biomass or diversity due to the loss of acceptable host plants is predicted to reduce the production of the many insectivores in higher trophic levels. An exhaustive search of host records in the literature enabled us to rank all 1385 plant genera that occur in the mid-Atlantic states of the U.S. by their ability to support Lepidoptera richness. Results/Conclusions Through several statistical comparisons we found that woody plants support more species of moths and butterflies than herbaceous plants, native plants support more species than introduced plants, and native woody plants with ornamental value support more Lepidoptera species than introduced woody ornamentals. All of these differences were highly significant. Our rankings provide a relative measure that will be useful for restoration ecologists, landscape architects and designers, land managers, and homeowners who wish to raise the carrying capacity of particular areas by selecting plants with the greatest capacity for supporting biodiversity.