Origin and spatio‐temporal diversification of a fishfly lineage endemic to the islands of East Asia (Megaloptera: Corydalidae)

Abstract Chauliodinae (fishflies), with their low capacity of long‐distance dispersal represent a suitable model insect group to investigate the biogeographical history. The genus Parachauliodes van der Weele, including the herein synonymized genus Sinochauliodes Liu & Yang, is endemic to East Asia. Here, we reconstruct the interspecific phylogeny of Parachauliodes based on mitochondrial DNA sequence data. Sinochauliodes syn.n. was recovered with a group of Parachauliodes species and not the sister group; we therefore treat it as the junior synonym of Parachauliodes . Species delimitation was performed combining the molecular identification with morphological evidence, with Parachauliodes inopinatus syn.n. treated as the junior synonym of Parachauliodes asahinai . The spatio‐temporal divergence pattern of Parachauliodes indicates that the genus might have originated from Eurasian continent no later than the early Miocene and the initial divergence within genus was likely to be correlated to the split of southwestern Japanese Islands from the continent. There likely was a southward dispersal in the Parachauliodes japonicus clade from southwestern Japan via the Ryukyus to Taiwan by the end of the Miocene. The present species diversity of the insular lineage of Parachauliodes was possibly shaped by island isolations and sympatric distribution.