Analysis of the Complete Mitochondrial Genome of an Invasive Bark Beetle Species, Hylurgus ligniperda (Coleoptera: Curculionidae, Scolytinae)

【 Objective】 In this study, the complete mitochondrial genome of Hylurgus ligniperda was characterized and analyzed for the first time, and the phylogenetic relationships between H. ligniperda and closely related coleopteran species was reconstructed at mitochondrial genomic level. This study aims to enrich the mitochondrial genome diversity of curculionids, and facilitate molecular identification, population monitoring and control of the invasive pest species H. ligniperda.【Method】The mitochondrial genome of H. ligniperda was sequenced using Illumina Novaseq 6000 platform, and was annotated and characterized based on published mitochondrial genomes of other Coleoptera species. The secondary structures of the tRNA genes were predicted using online tRNA Scan-SE 2.0 search server. Phylogenetic relationships between H. ligniperda and close related coleopterans were reconstructed using the maximum likelihood method based on mitochondrial genomes from a total of 23 species. 【Result】1) The complete mitochondrial genome of H. ligniperda is a circular structure, which is 15 912 bp in size and contains 37 genes, including 13 protein coding genes (PCGs), 22 tRNA genes and 2 rRNA genes, and a control region. The arrangement of all the 37 genes retains the same order and direction as the ancestral insect mitochondrial genome. 2) Nucleotide composition exhibits distinct AT-bias, with A + T content of 74.50%, G + C content of 23.80%; and the AT-skew value is 0.06, and GC-skew value is -0.24. 3) Except for the gene nad5, the other PCGs have the standard start codon ATN; and the stop codon of all PCGs is TAA or T. Except for trnS1, all tRNA genes display the secondary structures as classic clover-leaf shape. 4) Phylogenetic analysis based on mitochondrial genomes support that all the four subfamilies chosen from Curculionidae in present study are monophyletic, and they are branched as (Entiminae + ((Cryptorhynchinae + Molytinae) + Scolytinae)). 【 Conclusion】Mitochondrial genome of H. ligniperda is conserved in structure and codon usage, and shows distinct A + T biased nucleotide composition. Phylogenetic relationships of H. ligniperda and the close relatives yielded by mitochondrial genomes are consistent with previous morphological investigations. © 2024 Chinese Society of Forestry. All rights reserved.