The rapid development of next-generation sequencing (NGS) has greatly accelerated research on insect mitochondrial genomes (mitogenomes), which are now widely used in phylogenetics, population genetics, and species identification. Here, we sequenced and characterized the complete mitogenome of Chrysolina exanthematica, an economically important pest of medicinal plants in the subfamily Chrysomelinae. The mitogenome was 16,177 bp in length with an AT content of 78.46%, comprising the canonical 37 genes found in insect mitogenomes, including 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), and two ribosomal RNA genes (rRNAs), as well as a putative control region (CR) of 1,553 bp. The Ka/Ks ratios of all 13 PCGs within Chrysolina were below 1, indicating that they were subject to purifying selection. Extensive taxon sampling revealed that Oreina alpestris was nested within the Chrysolina clade, forming a strongly supported sister-group relationship with C. exanthematica (BS = 97%, PP = 1.00) in both maximum likelihood and Bayesian inference analyses, thus demonstrating the non-monophyly of Chrysolina. Furthermore, the mitogenome characterized here provides reliable molecular markers for the accurate identification of this economically important leaf beetle.
Jiao et al. (Sat,) studied this question.