Yagder serratus, a new eyeless weevil from Mexico and the non-monophyly of Brachycerinae, the evolutionary twilight zone of true weevils (Coleoptera: Curculionidae)

Abstract: We describe and illustrate a new eyeless weevil, Yagder serratus gen. & sp. nov., based on a single adult female collected by sifting forest leaf litter in Mexico. A phylogenetic analysis of 39 terminals and 2679 aligned positions from three DNA fragments places the new species into the subfamily Brachycerinae (as incertae sedis) and outside the highly diversified clade of ‘higher’ true weevils. Neither Brachycerinae, nor its tribe Raymondionymini traditionally uniting most eyeless weevils, are monophyletic unless the latter is limited to a Mediterranean core group. Both these taxa are taxonomic dumping-grounds likely containing species-poor sisters of species-rich clades. When resolved, the subfamily Brachycerinae will be likely split into two or more species-poor deeply-divergent subfamilies.

Key words: Coleoptera, DNA barcode, ITS2, 28S, phylogeny, forest litter, species discovery