Population genetic structure and intraspecific genetic distance of (Blattodea: Blattidae) based on mitochondrial and nuclear DNA markers.

The American cockroach () is a globally invasive pest that can cause significant economic loss and threaten human health. Although it is abundant and lives in close proximity to humans, few studies have investigated the genetic diversity of . Our study analyzed 1,053 and other species' samples from different locations in China and the United States. A traditional tree-based method using 17 unique mitochondrial COI haplotypes of and 20 haplotypes of the other species accurately identified with a barcoding threshold of 5.1%. To identify the population genetic structure of , we investigated gene and pooled them with obtained mtDNA data for a combined analysis. Although the genetic diversity of the USA group was relatively higher than the China group, the number of haplotypes and alleles of both groups was small. The analysis of molecular variance (AMOVA), intraspecific phylogeny, and haplotype networks indicated that had very little global genetic differentiation. The weak geographic genetic structure might reflect the human-mediated dispersal of . Despite no apparent phylogeographic assignment of mtDNA and nuclear lineages was observed in both BI trees, the integrated COI sequence data identified four distinct haplotype groups, showing four ancient maternal lineages of in China and the United States.