Unraveling the evolutionary history of the snakefly family Inocelliidae (Insecta: Raphidioptera) through integrative phylogenetics

Abstract

Inocelliidae is one of the two extant families of the holometabolan order Raphidioptera (snakeflies), with the modern fauna represented by seven genera and 44 species. The evolutionary history of the family is little-known. Here we present the first phylogenetic and biogeographical analyses based on a worldwide sampling of taxa and datasets combined with morphological characters and mitochondrial genomes, aiming to investigate the intergeneric phylogeny and historical biogeography of Inocelliidae. The phylogenetic inference from the combined analysis of morphological and molecular data recovered the sister-group relationship between a clade of (Negha + Indianoinocellia) + Sininocellia and a clade of Fibla + the Inocellia clade (interiorly nested by Amurinocellia and Parainocellia). Amurinocellia stat.r. and Parainocellia stat.r. et emend.n. are relegated to subgeneric status within Inocellia, whereas a newly erected subgenus of Inocellia, Epinocellia subgen.n., accommodates the former Parainocellia burmana (U. Aspöck and H. Aspöck, 1968) plus a new species Inocellia (Epinocellia) weii sp.n. Further, the Inocellia crassicornis group constitutes the nominotypical subgenus Inocellia stat.n., but the Inocellia fulvostigmata group is paraphyletic. Diversification within Inocelliidae is distinguished by an Eocene divergence leading to extant genera and a Miocene radiation of species. A biogeographical scenario depicts how the diverse inocelliid fauna from East Asia could have originated from western North America via dispersal across the Beringia during the early Tertiary, and how the Miocene ancestors of Inocellia could have accomplished long-distance dispersals via the Tibet-Himalayan corridor or eastern Palaearctic to western Palaearctic. Our results shed new light specifically on the evolution of Inocelliidae and, in general, the Raphidioptera.