Comparative Mitogenomics in the Genus Chlorophorus (Coleoptera: Cerambycidae) and Its Phylogenetic Implications

Chlorophorus Chevrolat, 1863, one of the most species-rich genera of Clytini, comprises 36 subgenera and 302 species/subspecies, with some species being of significant economic importance. To assess the monophyly and subgeneric system of this genus, we newly obtained mitochondrial genomic data from 21 species of Chlorophorus via high-throughput sequencing and reconstructed the phylogeny of this genus using ML and BI methods. The mitochondrial genomes of all sequenced Chlorophorus species were found to comprise 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and one non-coding region (control region, CR), reflecting a highly conserved gene arrangement. The mitochondrial genomes of the 21 Chlorophorus species range from 15,387 bp to 15,779 bp in length, and all exhibited AT bias. Analysis of the non-synonymous and synonymous substitution rates revealed that ATP8 has the highest evolution rate, whereas COI has the lowest. Further, phylogenetic analyses were performed based on different datasets (13 PCGs + 2 rRNAs, 13 PCGs + 2 rRNAs + 22 tRNAs, PCG123, PCG12) using maximum likelihood (ML) and Bayesian inference (BI) methods. The results indicate that Chlorophorus is monophyletic, but the subgenera Humeromaculatus Özdikmen, 2011; Immaculatoides Özdikmen, 2022; Brevenotatus Özdikmen, 2022; and Chlorophorus (s. str.) Chevrolat, 1863, are not monophyletic. Based on the comparison of male genitalia, we found that the sclerites of the endophallus may exhibit phylogenetic signals for the genus.