# Phylogenetic Analyses of Bostrichiformia and Characterization of the Mitogenome of Gibbium aequinoctiale (Bostrichiformia Ptinidae)

## TL;DR

This study analyzes the mitochondrial genome of a Ptinidae beetle and provides new insights into the evolutionary relationships within the Bostrichiformia infraorder.

## Contribution

The first mitogenome of Ptininae and new phylogenetic insights into Bostrichiformia.

## Key findings

- The mitogenome of G. aequinoctiale is 17,020 bp and contains 37 mitochondrial genes and a control region.
- Phylogenetic analysis supports the monophyly of four families but not Ptinidae due to one divergent species.
- Dermestidae, Bostrichidae, and Ptinidae form a major clade with Bostrichidae and Ptinidae as sister groups.

## Abstract

Background: Ptinidae, within the infraorder Bostrichiformia, are a cosmopolitan, ecologically diverse but poorly known group. The phylogeny within Bostrichiformia and the monophyly of Ptinidae and its phylogenetic placement in Bostrichiformia remain contentious. Methods: In this research, we determined the entire mitochondrial genome (mitogenome) of Gibbium aequinoctiale, the first representative mitogenome of the subfamily Ptininae, and reconstructed the phylogenetic relationships for Bostrichiformia based on four mitochondrial datasets using maximum likelihood (ML) and Bayesian inference (BI) methods. Results: The mitogenome of G. aequinoctiale is a circular molecule spanning 17,020 bp and harbors 37 mitochondrial genes and a presumed control region (CR). The mitogenome exhibited a marked preference for the utilization of A and T bases, which was also observed in three kinds of genes and CR. AAT was inferred as the putative candidate initiation codon for cytochrome oxidase subunits 1 (COI). The control region contains three tandem repeats (TDRs) and one poly-thymine stretch (Poly-T) in both coding strands. The phylogenetic results appeared to support the monophyly of four families, Nosodendridae, Derodontidae, Dermestidae, and Bostrichidae, and the basal position of the latter two families within Bostrichiformia. However, the family Ptinidae was not verified as monophyly because of one species diverging from the main lineage. Three families, Dermestidae, Bostrichidae, and Ptinidae, clustered as the major clade in Bostrichiformia, among which Bostrichidae and Ptinidae grouped together as sister groups. Conclusions: The present study provides valuable mitochondrial information for Ptinidae and provides novel perspectives on the inner phylogeny within the infraorder Bostrichiformia.