Species diversification of the <i>Lucanus maculifemoratus</i> complex (Coleoptera, Lucanidae) in East Asia: Implications for biodiversity

Abstract Taxonomic delineation of the Lucanus maculifemoratus complex (Coleoptera, Lucanidae) helps to resolving their taxonomy and understanding the diversification processes that have shaped their species diversity and distribution in East Asia. Geological events, phylogeographic breaks and Miocene‐Pleistocene glaciations are postulated as pivotal factors contributing to the speciation of L . maculifemoratus complex in East Asia. The complex geological events, topographic diversity and monsoon systems played a crucial role in the divergence of the L. boileaui sublineages during the Pliocene. The speciation of L . maculifemoratus coincided with the separation of the Japanese Islands from the Chinese continent. Thereafter, climatic oscillations, dispersal–vicariance events and environmental heterogeneity involved in the subspeciation of L . maculifemoratus in the early Pleistocene. The formation of Taiwan Island was a predominant vicariance event for the speciation between L . dybowskyi and Taiwanese taxa. The drastic uplift of the Central Mountain Range led to the species diversification between L . ogakii and L . kanoi . Subsequent genetic differentiation of subspecies and the two L. kurosawai sublineages was strongly associated with the geographic isolation of mountain ranges during Pleistocene. Historical climate oscillations resulted in species pump effect for the genetic differentiation of L . dybowskyi . The recurrent glaciations in the late mid‐Pleistocene may have frequently facilitated gene flow between populations. Ambiguous phylogenetic relationships among L . dybowskyi , L . taiwanus and L. kanoi suggested potential incomplete lineage sorting, genetic introgression or recent divergence in the late Pleistocene.