The complete mitochondrial genome and phylogenetic analysis of the European map butterfly Araschnia levana (Insecta: Lepidoptera: Nymphalidae)

Mitogenomic phylogeny of nymphalid subfamilies confirms the basal clade position of Danainae (Insecta: Lepidoptera: Nymphalidae)

The phylogenetic relationships among the nymphalid subfamilies have largely been resolved using both morphological and molecular datasets, with the exception of a conflicting basal clade position for Libytheinae or Danainae that remains contentious between morphological and molecular studies. Several phylogenomic analyses have found that the danaine clade is sister to other nymphalid subfamilies; however, it largely depends on utilizing different molecular datasets, analysis methods, and taxon sampling. This study aimed to resolve the basal clade position and relationships among subfamilies and tribes of Nymphalinae by combining the most comprehensive available mitogenomic datasets with various analyses methods by incorporating a new Symbrenthia lilaea Hewitson sequence data. Phylogenetic relationships among 11 nymphalid subfamilies and the tribes of Nymphalinae were inferred by combining new and available mitogenomic sequence data from 80 ingroup and six outgroup species. The phylogenetic trees were reconstructed using maximum-likelihood (ML) and Bayesian inference (BI) methods based on five concatenated datasets: amino acid sequences and nucleotides from different combinations of protein-coding genes (PCGs), ribosomal RNA (rRNAs), and transfer RNA (tRNAs). Danainae is well-supported as the basal clade and sister to the remaining nymphalid subfamilies, except for the paraphyletic Libytheinae. Libytheinae was either recovered as a sister to the danaine clade followed by the satyrine clade or sister to the nymphaline + heliconiine clades, and is consistent with recent phylogenetic studies on Nymphalidae. The monophyletic Nymphalinae has been recovered in all analyses and resolves tribal-level relationships with high support values in both BI and ML analyses. We supported the monophyletic Nymphalini as a sister clade to Victorini, Melitaeini, and Kallimini + Junoniini with high supporting values in BI and ML analyses, which is consistent with previously published morphological and molecular studies.

The complete mitochondrial genome of the pirate butterfly Catacroptera cloanthe (Stoll, 1781) (Insecta: Lepidoptera: Nymphalidae: Kallimini)

The pirate butterfly Catacroptera cloanthe (Stoll, 1781) (Nymphalidae: Kallimini) is a monotypic genus of butterfly that occupies grassland and savanna habitats in Sub-Saharan Africa, and exhibits seasonal variation. Genome skimming by Illumina sequencing allowed the assembly of a 78.8% AT-rich complete circular mitogenome of 15,204 bp from C. cloanthe. The mitogenome has a typical butterfly gene order consisting of 13 protein-coding genes, two rRNAs, 22 tRNAs, and a control region. Catacroptera cloanthe COX1 begins with an atypical CGA start codon, while COX2, ND3, ND4, and ND5 end with incomplete T or TA stop codons, completed by the addition of the poly-A tail during mRNA processing. Bayesian phylogenetic reconstruction placed Catacroptera cloanthe as sister to Mallika jacksoni in the monophyletic tribe Kallimini, which was consistent with previous phylogenetic hypotheses.

Phylogenetic analysis of the complete mitochondrial genome of the Japanese peacock butterfly Aglais io geisha (Stichel 1907) (Insecta: Lepidoptera: Nymphalidae)

The peacock butterfly Aglais io (Linnaeus, 1758) (Nymphalidae: Nymphalinae: Nymphalini) is a colorful and charismatic flagship butterfly species whose range spans from the British Isles and Europe through temperate Asia and the Far East. In Europe, it has been used as a model species for studying the effects of GMO maize pollen on caterpillar growth and survivorship. The Japanese subspecies, Aglais io geisha (Stichel 1907), is not as well studied as its European counterpart. Genome skimming by Illumina sequencing allowed the assembly of a complete circular mitochondrial genome (mitogenome) of 15,252 bp from A. io geisha consisting of 80.6% AT nucleotides, 13 protein-coding genes, 22 tRNAs, two rRNAs, and a control region in the gene order typical of butterfly species. Aglais io geisha COX1 gene features an atypical start codon (CGA) while COX1, COX2, CYTB, ND1, ND3, ND4, and ND5 display incomplete stop codons finished by the addition of 3' A residues to the mRNA. Bayesian phylogenetic reconstruction places A. io geisha within a clade with European A. io mitogenomes in the tribe Nymphalini, which is consistent with previous phylogenetic hypotheses.

Complete mitochondrial genome of the summer heath fritillary butterfly, Mellicta ambigua (Lepidoptera: Nymphalidae)

We sequenced the mitochondrial genome (mitogeome) of the summer heath fritillary bullterfly, Mellicta ambigua Ménétriès, 1859 (Lepidoptera: Nymphalidae), which is listed as an endangered insect in South Korea. The 15,205-bp long complete genome contained 13 protein-coding genes (PCGs), 2 rRNA genes, 22 tRNA genes, and 1 A + T-rich region with an arrangement identical to that observed in most insect mitogenomes. Unlike the other PCGs, COI had the atypical CGA start codon frequently found in lepidopteran COI. The A/T content of the whole mitogenome was 80.57%; however, it varied among the regions/genes as follows: A + T-rich region, 93.39%; srRNA, 85.37%; lrRNA, 84.92%; tRNAs, 81.13%; and PCGs, 79.22%. Phylogenetic analyses using concatenated sequences of the 13 PCGs and 2 rRNAs placed M. ambigua as a sister group to the within-tribe species, Melitaea cinxia, with the highest nodal support both in the maximum-likelihood (ML) and Bayesian inference (BI) methods.

The European Map Butterfly Araschnia levana as a Model to Study the Molecular Basis and Evolutionary Ecology of Seasonal Polyphenism

The European map butterfly Araschnia levana is a well-known example of seasonal polyphenism. Spring and summer imagoes exhibit distinct morphological phenotypes. Key environmental factors responsible for the expression of different morphs are day length and temperature. Larval exposure to light for more than 16 h per day entails direct development and results in the adult f. prorsa summer phenotype. Less than 15.5 h per day increasingly promotes diapause and the adult f. levana spring phenotype. The phenotype depends on the timing of the release of 20-hydroxyecdysone in pupae. Release within the first days after pupation potentially inhibits the default "levana-gene-expression-profile" because pre-pupae destined for diapause or subitaneous development have unique transcriptomic programs. Moreover, multiple microRNAs and their targets are differentially regulated during the larval and pupal stages, and candidates for diapause maintenance, duration, and phenotype determination have been identified. However, the complete pathway from photoreception to timekeeping and diapause or subitaneous development remains unclear. Beside the wing polyphenism, the hormonal and epigenetic modifications of the two phenotypes also include differences in biomechanical design and immunocompetence. Here, we discuss research on the physiological and molecular basis of polyphenism in A. levana, including hormonal control, epigenetic regulation, and the effect of ecological parameters on developmental fate.

The complete mitochondrial genome of the Indian leafwing butterfly Kallima paralekta (insecta: Lepidoptera: Nymphalidae)

The Indian leafwing butterfly Kallima paralekta (Horsfield, 1829) (Nymphalidae) is an Asian forest-dwelling, leaf-mimic. Genome skimming by Illumina sequencing permitted assembly of a complete circular mitogenome of 15,200 bp from K. paralekta consisting of 79.5% AT nucleotides, 22 tRNAs, 13 protein-coding genes, two rRNAs and a control region in the typical butterfly gene order. Kallima paralekta COX1 features an atypical CGA start codon, while ATP6, COX1, COX2, ND4, ND4L, and ND5 exhibit incomplete stop codons completed by 3' A residues added to the mRNA. Phylogenetic reconstruction places K. paraleckta within the monophyletic genus Kallima, sister to Mallika in the subfamily Nymphalinae. These data support the monophyly of tribe Kallimini and contribute to the evolutionary systematics of the Nymphalidae.

Phylogenetic analysis of the complete mitochondrial genome of the white peacock butterfly Anartia jatrophae saturata (Insecta: Lepidoptera: Nymphalidae)

The white peacock butterfly Anartia jatrophae saturata Staudinger, 1884 (Nymphalidae: Nymphalinae: Victorini), lives in the neotropics. Genome skimming with Illumina sequencing of A. jatrophae saturata allowed the assembly of a complete circular mitogenome of 15,297 bp, consisting of 81.4% AT nucleotides, 22 tRNAs, 13 protein-coding genes, two rRNAs, and a control region. Anartia jatrophae COX1 features an atypical start codon (CGA); ATP6, COX1, ND1, ND4, ND4L, ND5, and ND6 exhibit incomplete stop codons completed in the mRNA by the addition of 3' A residues. Contrary to previous phylogenetic hypotheses, phylogenetic reconstruction places A. jatrophae as sister to nymphalid tribe Nymphalini.