We explored the population structure and demographic history of an endemic but widespread Oriental dobsonfly, Neoneuromus ignobilis Navás (Megaloptera: Corydalidae), based on mitochondrial genomic and microsatellite datasets. Our results show that the 20 geographical populations of N. ignobilis presently sampled in East and Southeast Asia belong to five major lineages discriminated as southern Vietnam, Yunnan + Laos + northwestern Vietnam, southwestern Guangxi, central China and eastern China. We propose that early differentiation of populations probably occurred in Indochina and Yunnan due to vicariance events, and that populations from central and eastern China might have originated from southwestern Guangxi by dispersal. The continuous population expansion since the last interglacial, as revealed by demographic history and niche modelling analyses, explains the widespread pattern of N. ignobilis and highlights the relatively weak impact of the Quaternary glaciations on the East Asian biota. [ABSTRACT FROM AUTHOR]