Complete mitochondrial genomes of two moths in the tribe Trichaeini (Lepidoptera: Crambidae) and their phylogenetic implications

The complete mitochondrial genomes of two Prophantis species in the tribe Trichaeini (Lepidoptera: Crambidae) were sequenced using high-throughput sequencing technology. They were assembled and annotated: The complete mitogenomes of P. octoguttalis and P. adusta were 15,197 and 15,714 bp, respectively, and contain 13 protein-coding genes (PCGs), 22 transfer RNA genes, two ribosomal RNA genes, and an A + T-rich region. Their arrangement was consistent with the first sequenced mitogenome of Bombyx mori (Bombycidae) in Lepidoptera, which had the trnM-trnI-trnQ rearrangement. The nucleotide composition was obviously AT-biased, and all PCGs, except for the cox1 gene (CGA), used ATN as the start codon. Except for trnS1, which lacked the DHU stem, all tRNA genes could fold into the clover-leaf structure. The features of these two mitogenomes were highly consistent with those of other species of Spilomelinae in previous studies. Phylogenetic trees of Crambidae were reconstructed based on mitogenomic data using maximum likelihood and Bayesian inference analysis methods. Results showed that Trichaeini in this study robustly constitute a monophyletic group in Spilomelinae, with the relationships (Trichaeini + Nomophilini) + ((Spilomelini + (Hymeniini + Agroterini)) + Margaroniini). However, the affinities of the six subfamilies Acentropinae, Crambinae, Glaphyriinae, Odontiinae, Schoenobiinae, and Scopariinae within the "non-PS Clade" in Crambidae remained doubtful with unstable topologies or low supports.