The assessment of macroecological patterns in butterfly-host plant associations at a global scale
Plant-animal associations have been studied in many different contexts in the past, and a great amount of local knowledge has accumulated in several sources and over decades of research. Here we show how available on-line resources facilitate the integration of this knowledge with modern analysis tools in order to improve our understanding of macroecological patterns in biotic associations between butterflies and their hostplants. We found a total of 50,969 records of butterfly-hostplant associations in on-line databases, open-access literature and biodiversity portals, and validated 86% of them with taxonomic and bibliographic tools. The final compilation includes information from 5,152 butterfly species (28.6% of worldwide species of Papilionoidea) and 1,193 genera (66.3%), associated with 6,008 host plant species, from 2,289 genera and 212 families. We summarized the information in association matrices at different taxonomic and geographic levels, and calculated diet breadth and phylogenetic dissimilarity in host species. We used consensus butterfly and plant phylogenies, and summarized distribution records for all butterfly species, plant species and genera in our compilation.We found a significant and strong correlation between host plant diversity and butterfly species diversification at the subfamily level, but there are extreme examples of generalization and specialization at higher taxonomic level. The Fabales is used more frequently than any other plant order across all seven butterfly families and most subfamilies, while Poales, the second most frequently used order, is mostly restricted to two species-rich subfamilies. For most butterfly families, diet breadth can explain up to 18% in the variation in the distribution range of the species, but it was uninformative for Hesperiidae and Riodinidae. We also found complex latitudinal patterns in diet breadth, with more specialization in the Neotropics and Afrotropics, but apparently more overlap in resource utilization in the Oriental region.
This presentation was held at the 7th International Conference on the Biology of Butterflies, in Turku, Finland, 11-14 August 2014.
This work was supported by a 2013 EOL Rubenstein Research Fellowship Award.
