The family Erotylidae belongs to the superfamily Cucujoidea, which are phytophagous and mycophagous. So far, only two representative complete mitochondrial (mt) genomes of Erotylidae have been sequenced. Mitochondrial genomes of Tritoma metasobrina, Neotriplax arisana, and Episcapha opaca, which all belong to the subfamily Erotylinae, were sequenced using next-generation sequencing technology to better understand the diversity of mt genomes of Erotylidae. A comparative mt genomic analysis was conducted on the three sequenced representatives of Erotylinae and Languriinae sp. (Languriinae). The size of the complete mt genome of the 4 species ranged from 15,581 bp to 16,502 bp in length, including 37 genes (13 protein-coding genes, 22 transfer RNAs, and 2 ribosomal RNAs) and the control region. The arrangements of their mt genomes are highly consistent with other Coleoptera species. The start codons of two PCGs (ND1 and ND5) and the stop codons of one PCG (ATP8) were illustrated differences between Languriinae sp. and the other three species. All tRNAs of these 4 species exhibited cloverleaf secondary structures except that the dihydorouridine (DHU) arm of tRNASer(AGN) was absent. The phylogenetic analyses using both Bayesian inference (BI) and maximum likelihood (ML) methods all supported that Erotylidae as monophyletic. Erotylinae was monophyletic being the sister group to Xenocelinae. Languriinae was closely related to 'Erotylinae-Xenocelinae'. Our results recovered Languriinae nested within Erotylidae.
Keywords: Erotylidae; mitochondrial genome; phylogenetic relationships.