Pedro G. Ribeiro1,2,3, Darli Massardo4, Renato Rogner Ramos5, Marília B. Lion6, Márcio Zikán Cardoso6,7, Marcus R. Kronforst4, André V. L. Freitas5, Marcelo Mendes Brandão1, Karina L. Silva-Brandão1,8
1Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas 13083-875, SP, Brazil;
2Institute of Entomology, Biology Centre of the Czech Academy of Sciences, České Budějovice 37005, South Bohemia, Czech Republic;
3Faculty of Science, University of South Bohemia, České Budějovice 37005, South Bohemia, Czech Republic;
4Department of Ecology & Evolution, The University of Chicago, Chicago 60637, IL, USA;
5Departamento de Biologia Animal and Museu de Zoologia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas 13083-862, SP, Brazil;
6Departamento de Ecologia, Universidade Federal do Rio Grande do Norte, Natal 59072-970, RN, Brazil;
7Departamento de Ecologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil;
8Leibniz Institute for the Analysis of Biodiversity Change, Museum of Natur – Zoology, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany.
Amazonian white sand ecosystems (WSEs) are isolated patches of scleromorphic vegetation above white sandy soils that occur exclusively in the Amazon Forest. Due to unique soil characteristics, harsh irradiation, and temperature conditions, these ecosystems present low diversity and high floral and faunal endemism. Nevertheless, they are underrepresented in geological and biological studies, especially regarding the genetic structure and diversity of the species inhabiting them. Here, we investigated the genetic differentiation among populations of Heliconius hermathena Hewitson, 1854 (Lepidoptera, Nymphalidae), a specialized butterfly on the Amazonian white sand ecosystems, as well as their associated Wolbachia endosymbionts. Using the mitochondrial genome, we inferred high levels of genetic differentiation among individuals from six different subspecies of H. hermathena occurring in eight different localities. We also found high levels of structure among H. hermathena populations and postulated that isolation of WSEs and genetic drift must have played an important role in generating and maintaining the species’ current patterns of genetic differentiation. The infection by Wolbachia reached 97% of the specimens, and although isolated both genetically and geographically, the populations investigated share similar Wolbachia contigs. We discuss the importance of habitat isolation for population structure in Amazonia and, therefore, its contribution to the outstanding biodiversity in the region and to the comprehension of the diversification of its endemic species. We also discuss the role of this emblematic species as a model to understand butterfly diversity in isolated environments.
Key words: Amazonia, campinas, mitochondrial genome, Nymphalidae, Wolbachia.