Systematics and biogeography of the dobsonfly genus Nevromus Rambur (Megaloptera: Corydalidae: Corydalinae) from the Oriental realm

The Asian endemic dobsonfly genus Nevromus Rambur is revised. Six species of Nevromus are described or re‐described, and illustrated. Nevromus aspoeck Liu, Hayashi & Yang sp.n. , Nevromus austroindicus Liu & Viraktamath sp.n. and Nevromus gloriosoi Liu, Hayashi & Yang sp.n. are described from southernmost Yunnan of China and northern Thailand, southern India, and Borneo, respectively. A new combination Nevromus intimus (McLachlan) comb.n. is also identified. An interspecific phylogeny of Nevromus is reconstructed based on the adult morphological data, resulting in identification/recognition of two main clades, i.e. the mainland clade and the insular clade. Combining this phylogeny and the updated geographical distribution, an Indian origin and a historically widespread distribution in southern Eurasia is proposed for Nevromus. The deep divergence between the mainland and insular clades within Nevromus might have happened during the separation of Sundaland from Eurasia. The Tertiary orogenic events after the collision between the Indian subcontinent and Eurasia probably affected the speciation within the mainland clade of Nevromus, whereas the island formation of Borneo, Java and Sumatra shaped the fauna within the insular clade of this genus. The biogeographical pattern of Nevromus revealed in this study appears to have more general significance for understanding the faunal origin and diversification of the habitat‐specific or poorly dispersing insects from the Oriental realm.