Nymphalini

Abstract: The first empirically supported phylogenetic hypothesis of relationships for the southern African endemic butterfly tribe Dirini is presented. Data derived from the morphology and ecology of the adults and immature stages (33 characters), and portions of the mitochondrial gene cytochrome oxidase I (COI) and the nuclear genes elongation factor 1α (EF1α) and wingless (WG) (totalling 1734 bp) were used to infer the relationships of the in-group genera. An expanded molecular dataset using four genera from the Nymphalini and Satyrini to root the tree, and three genera from the Melanitini to test the monophyly of the tribe, was analysed using parsimony and Bayesian methods. Estimates of divergence times were calculated using two fossil calibrations under a relaxed molecular clock model. The monophyly of the tribe and each in-group genus were strongly supported. Key findings are the sister-taxon relationship of Aeropetes and Tarsocera, the apparent simultaneous or nearly simultaneous radiation of four lineages, the polyphyly of the species within Torynesis, and the apparent trans-Atlantic dispersal of the ancestors of Manataria about 40 Ma. Estimates of divergence times indicate that the tribe has undergone two major radiations since its origin: the first when they left forest habitats in the mid–late Oligocene, shortly after the radiation of the grasses (Poaceae), and the second in the early-middle Pliocene, coinciding with the aridification of southern Africa and the spread of conditions that favoured C4 grasses over the C3 grasses that dirine larvae prefer to eat. The high species diversity within the tribe appears to be partly a taxonomic artefact that may have resulted from the misinterpretation of climate-related phenotypic variation within extant species. Relocation and breeding experiments should test this hypothesis.

Abstract: The buckeye butterflies (genus Junonia) that occur in Florida, USA have been an ongoing taxonomic challenge for over 100 years. Schwartz (1987. Milwaukee Pub. Mus. Contrib. Biol. Geol. 73: 21) described the situation succinctly: “No other lepidopteran on the Florida Keys nor in south Florida, presents the taxonomic problems as Junonia.” The current consensus recognizes 3 different forms of Junonia in Florida based on morphological characters, but there is a general lack of consensus regarding the appropriate scientific names for each form. Similarities between the species that occur in Florida, intraspecific variation, and possible hybridization between species have often made it challenging to identify specimens, define the population structure of Junonia butterflies, or to understand the relationships of these butterfly populations to those elsewhere in the New World. We use a combination of morphological characters, mitochondrial cytochrome oxidase I barcodes, nuclear wingless DNA sequences, and randomly amplified DNA fingerprints from Junonia from Florida, the Caribbean, and North and South America to resolve issues of taxonomy and population structure in this genus. We conclude that the common buckeye (J. coenia), the mangrove buckeye (J. neildi), and the tropical buckeye (J. zonalis) occur in Florida and that hybridization between these species takes place in this region.

Abstract: The first empirically supported phylogenetic hypothesis of relationships for the southern African endemic butterfly tribe Dirini is presented. Data derived from the morphology and ecology of the adults and immature stages (33 characters), and portions of the mitochondrial gene cytochrome oxidase I (COI ) and the nuclear genes elongation factor 1 α (EF1 α )a ndwingless (WG) (totalling 1734 bp) were used to infer the relationships of the in-group genera. An expanded molecular dataset using four genera from the Nymphalini and Satyrini to root the tree, and three genera from the Melanitini to test the monophyly of the tribe, was analysed using parsimony and Bayesian methods. Estimates of divergence times were calculated using two fossil calibrations under a relaxed molecular clock model. The monophyly of the tribe and each in-group genus were strongly supported. Key findings are the sister-taxon relationship of Aeropetes and Tarsocera, the apparent simultaneous or nearly simultaneous radiation of four lineages, the polyphyly of the species within Torynesis, and the apparent trans-Atlantic dispersal of the ancestors of Manataria about 40 Ma. Estimates of divergence times indicate that the tribe has undergone two major radiations since its origin: the first when they left forest habitats in the mid-late Oligocene, shortly after the radiation of the grasses (Poaceae), and the second in the early-middle Pliocene, coinciding with the aridification of southern Africa and the spread of conditions that favoured C4 grasses over the C3 grasses that dirine larvae prefer to eat. The high species diversity within the tribe appears to be partly a taxonomic artefact that may have resulted from the misinterpretation of climate-related phenotypic variation within extant species. Relocation and breeding experiments should test this hypothesis.