3.6 Phylogenetic Relationships
In this study, we conducted phylogenetic analysis on 39 butterfly species (including 4 outgroup species) with ML and BI methods based on three datasets (PCGs, PRT and 12PRT). Results show that the obtained phylogenetic trees harbored almost the same topological structures, with nodes of the tree being strongly supported (the bootstrap support values, BS, of ML trees and the posterior probability, PP, of the BI trees). Due to the limitation of the length of the paper, only one (PCGs-BI) of the six phylogenetic trees is shown here (Figure 5). The rest of the trees are in the supplementary materials (Figure S1—S5).
The phylogenetic tree consists of 8 clades corresponding to 8 major hesperiid subfamilies, and their relationships are (Coeliadinae + (Euschemoninae + ((Pyrginae + (Eudaminae + Tagiadinae)) + (Heteropterinae + (Barcinae + Hesperiinae))))) (Figure 5). The position of Eudaminae does not agree with that of previous studies where the subfamily is sister to the Pyrginae sensu lato, ie. Tagiadinae, Pyrrhopiginae, and Pyrginae sens Zhang et al (Jing Zhang et al., 2019). For the 3 Aeromachini species in this study, all results indicate thatH.nephele and O.maga are sister groups (PP=1), and theH.nephele + O.maga calde is sister to A.virgatawith strong support values (PP=1). The Aeromachini form an independent clade in the subfamily Hesperiinae, which is the subbasal lineage among them (PP=1). Although our analyses did not select sufficient samples of representative groups, for example the Eudaminae, a satisfactorily clustering and high node support values were present in all the obtained trees.
Apostictopterus fuliginosus and Barca bicolor had been placed in the subfamily Heteropterinae in previous research (Warren et al., 2008, 2009; Yuan et al., 2015) until Han et al. proposed thatA. fuliginosus and B. bicolor should be placed in subfamily Hesperiinae through phylogenetic analysis of mitogenomes (Han et al., 2018). Subsequently Zhang et al, adding Trapezitinae in their analysis, raised them to a subfamily rank Barcinae (Jing Zhang et al., 2019). Since we could not include Trapezitinae in our analysis, we can only conclude that the hypothesis to place A. fuliginosus and B. bicolor out of the subfamily Heteropterinae is correct, and whether Barcinae is an independent subfamily or not needs further research.
4. Conclusions
Three mitogenomes of species in the tribe Aeromachini (Amipittia virgata , Halpe nephele and Onryza maga ) were sequenced to provide more comprehensive molecular data for phylogenetic status in this study. The size and structure of mitochondria, gene order, and AT content of these three species are highly consistent with other Lepidoptera species. We conducted the phylogenetic analyses using ML and BI methods, and the results show that Aeromachini is a monophyletic group and sister to the rest of Hesperiinae and that the relationships among hesperiid subfamilies is Coeliadinae + (Euschemoninae + ((Pyrginae + (Eudaminae + Tagiadinae)) + (Heteropterinae + (Barcinae + Hesperiinae)))). Moreover, we support the previous study placing A. fuliginosus and B. bicolor out of the subfamily Hesperiinae. Our research provides data and a framework for the phylogeny of the tribe Aeromachini as well as even the family Hesperiidae.
Data Availability Statement
The following information was supplied regarding the availability of DNA sequences: The complete mitogenome of Amipittia virgata ,Halpe nephele and Onryza maga is deposited in GenBank of NCBI under accession number MW288057, MW288058 and MW288059, respectively.