The evolutionary history of B iston suppressaria ( G uenée) ( L epidoptera: G eometridae) related to complex topography and geological history

The Mountains of Southwest China (MSC) – the most important mountain system in E ast A sia – creates physical barriers to migration and isolates organisms in different regions. In this study, we explored the genetic structure and phylogeography of B iston suppressaria , a moth species widely distributed in MSC and south C hina, based on three mt DNA and three nc DNA loci. M t DNA revealed high genetic differentiation among the geographical populations and divided B . suppressaria into five phylogroups ( A–E ). With the exception of phylogroups B and E which are sympatric, the other three phylogroups have their own distinct distribution areas. Four population differentiations occurred, and the divergence time was consistent with the three phases of the Q inghai– T ibet M ovement and K unhuang M ovement, respectively. In contrast, nc DNA did not reveal any phylogeographical structure. Incomplete lineage sorting is considered the most plausible cause of the discordance between mt DNA and nc DNA genes, after excluding secondary admixture and W olbachia infection. A complex combination of topography and geological movements of south C hina and MSC contributes to the complex evolutionary history of B . suppressaria .