Subtribal classification of Metriorrhynchini (Insecta: Coleoptera: Lycidae): an integrative approach using molecular phylogeny and morphology of adults and larvae

The classification of Metriorrhynchini, the most diverse lineage of net-winged beetles (Lycidae) containing ~ 1400 species, is revised on the basis of three-marker molecular phylogeny of 175 ingroup taxa, and the adult and larval morphology. The study uses the molecular phylogeny for identification of major lineages and critically considers morphology when adult morphology and sparse information of immature stages alone did not provide enough information for building a robust classification. Reconstruction of the ancestral states of morphological characters on the phylogenetic tree recovered from DNA data presents evidence for multiple origins of the four-costae pattern on the elytra, shortened elytral costa 1, patterns of pronotal areolae and flabellate antennae. As a consequence, revised morphological delineations of the subtribes and genera are proposed: three major lineages are defined as Metriorrhynchina Kleine, 1926, Metanoeina subtrib. nov. and Cautirina subtrib. nov. The subtribes Trichalina Kleine, 1928 and Hemiconderina Bocak & Bocakova, 1990 are synonymized with Metriorrhynchina Kleine, 1926. Metanoeina are studied in detail and three genera are placed in the subtribe: Metanoeus Waterhouse, 1879, Xylometanoeus gen. nov., and Matsudanoeus gen. nov., with Xylometanoeus japonicus (Bourgeois, 1902) comb. nov. and Matsudanoeus yuasai (Nakane, 1969), comb. nov. as type species, respectively. Xylobanus basivittatus Nakane, 1970 is transferred to Xylometanoeus. The concepts of genera Cautires and Xylobanus are based on male and female genitalia. Additionally, the molecular hypothesis is supported by morphology of larvae, when newly proposed Cautirina are characterized by entire tergites in contrast to the longitudinally divided mesoand metathoracic tergites of Metanoeina and Metriorrhynchina. Larval characters support the placement of Xylometanoeus in Metanoeina and the close relationships of Matsudanoeus and Metanoeus. The simultaneous consideration of DNA-based phylogeny and morphology of adults and larvae rejects taxa based on diagnostically usable but strongly homoplastic characters and provides a framework for a robust classification of Metriorrhynchini