Pleistocene Climate Oscillations and Geographic Barriers Shaped the Phylogeographic Structure of Anaplecta omei (Blattodea, Blattoidea, Anaplectidae) in Southern China: Evidence from Mitochondrial Genomes

Anaplecta omei is the only species of Anaplecta widely distributed in southern China. However, previous studies have failed to elucidate the factors underlying its distribution pattern. This study aims to clarify the genetic diversity, population structure, and evolutionary history of A. omei, and explores the events that have influenced its differentiation and distribution patterns. We analyzed 97 complete mitochondrial sequences from 24 geographic populations of A. omei and conducted phylogenetic reconstruction, genetic diversity assessment, and population structure analysis. Additionally, we performed a selection test and estimated divergence times. Demographic history was examined using neutrality tests, mismatched distribution analysis and Bayesian Skyline Plot (BSP) analysis. Our results reveal that geographic populations of A. omei exhibit high haplotype diversity, low nucleotide diversity and a clear phylogeographic structure forming four distinct lineages. The selection tests suggested that the isolation of A. omei was driven by physical barriers, rather than adaptive divergence. By integrating divergence time estimates with demographic history analyses, we demonstrated that tectonic uplift, glacial climate oscillations, and local environmental complexity have collectively shaped the speciation and distribution of A. omei. These findings provide novel insights into the process of speciation and distribution within Blattodea.