Phylogeny Of The Main Lineages Of Butterflies (Rhopalocera) And Its Subgroup Papilioninae Based On Mitochondrial 16S RRNA Evidences

Butterflies are distributed worldwide. Their intriguing beauty and diversity have been made them one of the most beloved groups of invertebrates for us and are used as one of the important model organisms for the studies of evolution, population genetics, developmental biology, conservation biology, ecology, and so on.Up to now, many different classification systems for butterflies have been put forward among entomologists in China and abroad. However, their taxonomical and phylogenetic studies were mainly based on their morphological characteristics, and those on molecular evidences are still very limited. In this study, mitochondrial 16S rRNA gene sequence was used as a molecular marker, the phylogenetic trees of 35 species of Papilioninae butterflies covering 4 tribes and 12 genera were reconstructed using different mathematical methods, attempting to clarify their phylogenetic relationships. The results showed that the Lampropterini constituted a monophyletic group as the most basal branch in all of the molecular phylogenetic trees obtained; the Troidini was monophyletic, clustering within the Papilionini; the tribe Chilasa was one of the early diversified groups of Papilionini and may diverged earlier than the tribe Troidini from both of their closest ancestor upon the comprehensive analyses of their molecular, morphological and hostplant's features.Besides the studies for Papilioninae mentioned above, those about the main lineages of Rhopalocera were also made in this paper upon the 16S rRNA secondary structure for the reasons of uncongruencies in the former related morphological or molecular studies. The results showed that the secondary structures of all the representative species had six subdomains and their characteristics of molecular morphology were basically the same with the exception of Abraximorpha davidii, Curetis bulis and Abisara saturate, which had five subdomains. The combinated analyses on morphological and molecular criteria suggested that the Lycaenidae and Riodinidae were sister to each other, and the Libytheinae should not be classified into Lycaenoidea; the Zerynthiini was probably the middle type between Parnassiini and Papilioninae; the proposed opinions that the Pieridae may have a close relationship with Parnassiini and their grouping is sister to the papilionids was supported; in addition, it should be more reasonable to lift up the Acraeini and Amathusiini as the rank of subfamily, respectively. In conclusion, all these facts showed that the molecular morphology of 16S rDNA secondary structure is also one of the valuable sources for the phylogenetic inferrence.This study provided some new evidences for the phylogenetic relationships of Rhopalocera butterflies and its subgroup Papilioninae through the primary and secondary structure analyses of 16S rRNA gene sequence, aiming at setting up a more scientific and reasonable systematics category for the butterflies, especially for those distributed in our country.