Background: The family Buprestidae is one of the largest families in Coleoptera; however, the number of reported mitochondrial genomes for this family is limited. Methods: In this study, mitogenomes of Chrysobothris violacea, C. shirakii, Buprestis fairmairei, and Phaenops yin were sequenced, assembled, and annotated. The mitogenomes of Chrysobothris, Phaenops, and Buprestis are reported for the first time. Results: The mitogenomes of Chrysobothris violacea, C. shirakii, and Phaenops yin are complete, while the mitogenome of Buprestis fairmairei is partial, lacking trnV and 12S genes. The AT-skew of these four mitogenomes is positive (0.02–0.09). Among the protein-coding genes, the Ka/Ks ratio for cox1 is the lowest (0.05), and the nucleotide diversity for nd6 is the highest. Conclusions: The phylogenetic trees based on mitogenome sequences suggest that the target genus Chrysobothris is sister to Phaenops, and the target genus Buprestis is sister to (Melanophila + (Chrysobothris + Phaenops)) clade. The results of this study will provide mitogenomic data for further research on the mitogenome and phylogeny of Buprestidae.

To explore the mitogenome characteristics of Tetratomidae and the phylogenetic position of this family in Tenebrionoidea, the mitogenome of Penthe kochi Mařan, 1940 was sequenced, annotated, and analyzed. The P. kochi mitogenome is consistent with Tenebrionoidea species in gene length, genomic organization, codon usage, and secondary structures of transfer genes (tRNAs). Most protein-coding genes (PCGs) originate with a typical ATN start codon, except nad1 and nad3, which start with TTG. In total, 10 PCGs are terminated with complete stop codon TAA and TAG, while cox1, cox2, and nad 4 contain an incomplete stop codon T-. Among the 13 PCGs, nad2 (Pi = 0.282) has the most diverse nucleotide composition, and cox2 is the most conserved gene with the lowest value (Pi = 0.154). The Ka/Ks ratio of cox1 (0.076) and cox2 (0.124) has a lower value. All the tRNAs can be folded in a typical clover-leaf secondary structure, except trnS1, which lacked a dihydrouridine arm. And phylogenetic analyses were performed based on 13 PCGs using the Bayesian inference (BI) method. The results showed that the clade of Tenebrionoidea was well separated from the outgroups, and Tetratomidae and Mycetophagidae were not well resolved. Phylogenetic analyses with more mitogenome samplings are needed to resolve the phylogeny of Tenebrionoidea.

The number of known mitochondrial genomes in Buprestidae is limited, especially in Chrysochroinae, which seriously hinders the phylogenetic study of this family. The mitogenomes of Capnodis miliaris, Lamprodila cupreosplendens, Sphenoptera insidiosa and Philocteanus rubroaureus were sequenced, assembled and annotated in this study. The mitogenomes of these four species are typical circular double-stranded DNA molecules, containing 13 protein-coding genes (PCGS), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and a control region (CR). The total lengths of these four mitogenomes are moderate, ranging from 15,778 bp to 16,230 bp. Additionally, their A + T content ranges from 68.76% to 73.47%, showing positive AT-skew values ranging from 0.098 to 0.181. Relative Synonymous Codon Usage (RSCU) analysis indicated that TTT (Phe), ATT (Ile), TCT (Ser2), and TTA (Leu2) are the most frequently used codons. The gene arrangement of four mitogenomes is consistent with the previously reported Buprestidae mitogenomes. Most of the PCGs use ATN as the start codon, with TAA as the stop codon or an incomplete stop codon T-. Phylogenetic trees were constructed based on the PCGs and rRNAs using both maximum-likelihood and Bayesian inference methods. The phylogenetic results showed that Julodinae, Polycestinae, Buprestinae and Agrilinae are monophyletic groups, and Chrysochroinae is a paraphyletic group. As the number of Buprestidae mitogenomes used for polyogenetic analysis increases, the topology of phylogenetic tree shows differences compared to previous studies.