Evolutionary Trends in Phenotypic Elements of Seasonal Forms of the Tribe Junoniini (Lepidoptera: Nymphalidae)

Abstract

Seasonal polyphenism in insects is the phenomenon whereby multiple phenotypes can arise from a single genotype depending on environmental conditions during development. Many butterflies have multiple generations per year, and environmentally induced variation in wing color pattern phenotype allows them to develop adaptations to the specific season in which the adults live. Elements of butterfly color patterns are developmentally semiautonomous allowing for detailed developmental and evolutionary changes in the overall color pattern. This developmental flexibility of the color pattern can result in extremely diverse seasonal phenotypes in a single species. In this study, we asked the following questions: (a) How do wing phenotype elements such as shape and pattern vary between seasonal forms? (b) Can this variation be explained phylogenetically? (c) If so, what are the various pattern development strategies used to achieve crypsis in the dry season form? To answer these questions, we used high-resolution images to analyze pattern element variation of 34 seasonally polyphenic butterfly species belonging to the tribe Junoniini (Lepidoptera: Nymphalidae). We show that forewing shape and eyespot size both vary seasonally and that the methods by which phenotype elements change in the dry season forms are different in different clades and may therefore have independent and diverse evolutionary origins.

A global molecular phylogeny yields insights into the dispersal and invasion history ofJunonia, a butterfly genus with remarkable dispersal abilities

“…The sister clade to Junonia differs between mitochondrial and nuclear analyses. The mitogenome sister clade contains the genera Protogoniomorpha , Yoma and Salamis , with Salamis as the outgroup to the other two genera, consistent with some prior phylogenetic analyses [ 3 , 24 – 26 ]. Pyrcz et al .…”

“…The clade defined by the oldest node within the Junoniini (figures 2 and 3) contains the monophyletic genera Precis and Hypolimnas, as reported previously [3,24,25]. The sister clade to Junonia differs between mitochondrial and nuclear analyses.…”

“…Mallika jacksoni and Catacroptera cloanthe are assigned to tribe Kallimini as expected, but Kallima paralekta clusters with tribe Kallimoidini within subfamily Nymphalinae (figure 3). The clade defined by the oldest node within the Junoniini (figures 2 and 3) contains the monophyletic genera Precis and Hypolimnas, as reported previously [3,24,25]. The sister clade to Junonia differs between mitochondrial and nuclear analyses.…”

“…The first is an Asian forest-dwelling butterfly lineage containing species ( J. iphita , J. atlites , Junonia intermedia , Junonia adulatrix and J. hedonia ) that at rest have closed wings that masquerade imprecisely as leaves [58]. The second lineage includes African species that are also forest-dwelling but most are considered to be very good leaf mimics [24] (figure 4). There is one exception, Junonia sophia, which is thought to be a Batesian mimic of the false diadem butterfly ( Pseudacraea lucretia ) [59].…”

“…Morphology-based taxonomic assignments have become easier owing to recent clarification of New World species taxonomy [6,7,17,[20][21][22][23], but remain challenging for reasons described above, and owing to poorly described, undescribed and cryptic Junonia species [20,23]. In general, Junonia phylogenetic studies have either contained very few (≤3) New World species [9,24,25], or (≤2) Old World species [19,23]. Further, some phylogenetic studies of New World taxa have included GenBank sequences labelled as either Junonia evarete or Junonia genoveva, but in the absence of museum vouchers it is unclear if the source-specimens were correctly identified or if they belong to one of six other potential Junonia species [6,[16][17][18][19].…”