Mitochondrial Genome Comparison and Phylogenetic Analysis of the Family Carabidae (Coleoptera: Adephaga)

Abstract

The family Carabidae, one of the largest families within Coleoptera, represents one of the most important groups of predatory insects and bioindicators in ecosystems, playing significant roles in agricultural pest control and ecological environment assessment. However, the phylogenetic relationships within this family remain poorly resolved, and publicly available mitochondrial genome data remain limited. In this study, we employed high-throughput sequencing to determine and report for the first time the complete mitogenomes of four carabid species—Poecilus fortipes (Chaudoir, 1850) and Poecilus gebleri (Dejean, 1828) from the subfamily Pterostichinae, and Pristosia nitidula (A. Morawitz, 1862) and Cephalosdrophus marinae (Lassalle & Marcilhac, 1999) from the subfamily Platyninae—as well as to resequence Carabus brandti Faldermann, 1835 from the subfamily Carabinae. Using 124 carabid mitochondrial genome sequences obtained from NCBI, this study reconstructed the phylogenetic relationships among 21 subfamilies within Carabidae. The results showed that the sizes of mitochondrial genomes ranged from 15,800 to 17,352 bp in length and contained 37 typical genes and a control region. Combined with previously reported mitogenomic data, we found all protein-coding genes (PCGs) initiated with standard start codons ATN or TTG and ended with TAN or an incomplete stop codon single T. Evolutionary rate analysis (Ka/Ks) revealed ATP8 was the fastest-evolving gene, whereas COX1 was the slowest. Except for tRNA-Ser (AGN), whose DHU arm simply formed a loop, and tRNA-Phe (C. marinae), whose TΨC loop was absent, the rest of the tRNA sequences could be folded into a typical cloverleaf secondary structure. Our results suggest that the phylogenetic position and taxonomic status of Cicindelinae remain unresolved, with alternative placements recovered depending on the dataset analyzed. The monophyly of most carabid subfamilies was confirmed, with the exception of Brachininae, Trechinae, Licininae, and Platyninae. The findings of this study provide valuable insights into carabid phylogeny. Further refinement of the phylogenetic relationships within the family can be achieved by additional nuclear markers, broader taxon sampling, and complementary phylogenomic datasets.