Knowledge of phylogenetic relationships among the species comprising a rapid radiation has proved invaluable for detailed investigations into the processes and patterns of their diversification. There are still relatively few studies aimed at understanding the mechanisms of radiations for invertebrates, even in popular groups such as butterflies which feature prominent model-organisms in evolutionary biology . It is the lack of robust phylogenies for such groups that has imposed a crucial impediment for comparative analyses. Among butterflies, a phylogenetic perspective has been applied to a number of radiations (e.g. [2–6]). However, few butterfly groups can compare with the mycalesine radiation (Nymphalidae: Satyrinae: Satyrini: Mycalesina) in terms of diversity of species and geographic sweep. They have been acclaimed as one of the most spectacular butterfly radiations, comprising more than 270 species usually placed in six genera [7, 8]. Mycalesines are found across the Old World tropics in both forested and open habitats and are characterized by high levels of endemicity throughout their range. Unlike other butterfly radiations, which typically peak in diversity within a single zoogeographic region (e.g. Arhopala in SE Asia), all major palaeotropical regions - Madagascar, Africa, the Indian subcontinent, Indo-China, the larger islands of South-East Asia (notably Sulawesi), New Guinea and the Solomon Islands are each represented by a species-rich mycalesine fauna. The Indo-Australian, Afrotropical and Madagascan regions have roughly equal numbers of species . This group of butterflies thus presents an exciting opportunity to understand their diversification within a phylogenetic framework.
The level of diversity in fundamental body plan and in larval and adult feeding biology is relatively modest compared to other butterfly groups with similar species richness. This relative morphological and behavioural conservatism contrasts sharply with a spectacular array of scent organs found in males and some striking differences in expression of wing ocelli and colour patterns [7, 9]. The existing generic classification scheme has been based mostly on limited morphological characters such as the presence of hairy eyes (interommatidial setae), forewing venation [9–11] or scent organs , which have been considered inadequate character sets for resolving their systematics [13–15]. The circumscriptions of genera have been in a constant state of flux, with early revisions for instance  and  for Asian and African species respectively, and several more recent local revisions based on morphology.
Despite work on regional mycalesine faunas, there has been no coherent attempt to date to classify the entire group. The need for robust phylogenetic hypotheses from molecular data to resolve this issue has been stressed [8, 17]. A study on the mycalesines of Madagascar (also including a few African species; ) using molecular data from two mitochondrial genes (Cytochrome oxidase II and Cytochrome b) reported that the majority of Madagascan genera were not monophyletic, corroborating results from a previous morphological study . Accordingly, the pre-existing genera Henotesia, Admiratio and Masoura were subsumed under Heteropsis as sub-genera, while Houlbertia was sunk completely [8, 18]. The Afrotropical region now consists of three genera Heteropsis, Hallelesis and Bicyclus [9, 19]. The genus Heteropsis Westwood (1850) comprises around 81 known species of which 46 are described and a further ca. 24 undescribed species are known in the Malagasy Region [7, 18, 20]. About 12 Heteropsis species are distributed in continental Africa [21–24] whilst Hallelesis, with two species, is confined to West and Central Africa . Bicyclus consists of ca. 80 species in mainland Africa  with one species, B. anynana, also found in the Comoros . Species-level relationships within the genus were investigated in a molecular study , for which data from three other mycalesine genera were used to root the tree. Although Bicyclus was eventually recovered as a clade, their sampling of other genera was too poor to establish firm support for its monophyly.
The remaining three genera (Mycalesis Hübner, 1818, Lohora Moore, 1880 and Nirvanopsis Vane-Wright, 2003) are found in the Indo-Australian tropics. Mycalesis is the most species-rich among current mycalesine genera with estimates of the number of species ranging from 87 to over 100 [28–31]. This genus is almost ubiquitously distributed in the Indo-Australian region ranging from Sri Lanka and India in the West, across Indo-China, South-East Asia and New Guinea, to North-East Australia and the Solomon Islands in the East. Lohora and Nirvanopsis are endemic to Sulawesi. Lohora contains 17 species and Nirvanopsis was for a long time considered to be monobasic (previously as Nirvana), but now includes a recently described species, N. susah. It has been suggested that Mycalesis is probably paraphyletic with respect to Lohora , and that Nirvanopsis might belong within Lohora . Mycalesis was considered closely related to another Indo-Australian mycalesine genus Orsotriaena, but this has been refuted by recent molecular studies [32, 33]. Mycalesis differs from Bicyclus by the presence of hairy eyes; dense interommatidal setae are absent in the latter . Heteropsis also has hairy eyes  but differs from Mycalesis in details of wing venation and for most species, male genitalia . Mycalesis was divided into several genera , and into species groups by  and . Additional file 1 provides more information on taxonomical revisions and groupings of Asian and Australasian species.
The monophyly of genera and the relationships among them have strong implications for our understanding of their global diversification. Miller, whose study  was largely based on an examination of leg morphometrics, speculated that mycalesines started diverging in the Oriental region from an ancestor which was initially derived from Neotropical satyrines. According to his scenario, Africa was colonized twice, once by a naked eyed ancestor (leading to Bicyclus and Hallelesis) and by a hairy eyed ancestor that eventually went on to disperse into Madagascar (leading to Heteropsis) and went extinct in Africa. Miller further speculated that the hairy-eyed mycalesines dispersed into the Australasian region. Based on their tree where the African Heteropsis was nested within the Madagascan clade, Torres and colleagues  suggested an alternate scenario where Africa was colonized at least once from Madagascar.
Hostplant records for this group are scarce; the known records are mainly from Poaceae, but also from Cyperaceae, Marantaceae and Zingiberaceae . Most regional groups tend to be restricted to the forested tracts of lower altitudes [10, 36, 37], whereas in some regions such as Madagascar there is elevational zonation along the entire forest gradient . Mycalesines are generally low flying butterflies with weak to moderate dispersal abilities [8, 25, 39] (although the Heteropsis subgenera Masoura and Admiratio are canopy species, as is Nirvanopsis) [40, 41]. This low dispersal ability along with habitat and bioclimatic fidelity renders several species endemic to narrow regions [10, 40]. With some exceptions, species are dull and cryptically coloured, bearing a postdiscal series of eyespots (ocelli) on the dorsal and ventral surfaces that are sometimes not expressed on some wing surfaces or in both sexes. Species that experience defined periods of wet and dry seasons have a corresponding dry- and wet-season form . This polyphenism is characterized by the reduction of the ventral eyespots in the dry season morph.
Mycalesines have been used extensively in various ecological (e.g. [12, 40, 43, 44]) and evolutionary studies (e.g. [45–50]). Bicyclus in particular has carved a niche for itself as a model organism in evolutionary biology, with the eyespots in B. anynana having been the focus of innumerable evo-devo studies (e.g. [51–54]). Almost all species of Mycalesina possess eyespots, but, again, the lack of robust phylogenies has hindered comparative studies within a phylogenetic framework; the two studies on Bicyclus , and , are the only such studies so far.
No molecular study has incorporated sufficient species from all mycalesine genera for a rigorous test of their reciprocal monophyly. The two studies [8, 27] were focused on regional mycalesine faunas. The former study did include a sample of the type species of Mycalesis, M. francisca, but found no support for its placement. These authors concluded that denser taxon sampling was necessary to elucidate generic level relationships within the group. In this study, we attempt to infer the phylogeny of Mycalesina using sequence data from three genes. We also include 42 species of Mycalesis and seek to identify major lineages within the genus and their relationships. We estimate lineage divergence times within the group and attempt to reconstruct events in its biogeographic history.