Evolutionary history and divergence times of Tettigoniidae (Orthoptera) inferred from mitochondrial phylogenomics

Selective pressure analysis on the 13 protein-coding genes (PCGs) and 2 ribosomal RNA (rRNA) genes revealed that only <i>ND1</i> and <i>COX1</i> contained positively selected sites, while negative selection dominated across all genes, indicating that mitochondrial genes primarily function to maintain genetic integrity. Additionally, we assessed the evolutionary rates of the 13 PCGs and two rRNA genes across five major subfamilies using mean pairwise identity analysis. Phylogenetic results of our study provide more precise insights into the relationships within Tettigoniidae, spanning subfamilies, tribes, genera, and species. We further estimated the divergence times of Tettigoniidae using four fossil calibration nodes in MCMCTree, dating the origin of katydids to the early Paleogene period (approximately 60.86 Mya), and identifying the divergence nodes for five major subfamilies.