New and revised taxa of Neotropical Diplotaxini (Coleoptera: Melolonthidae): do they change the existing relationships? Revisiting systematics with morphological and molecular data

Abstract

Abstract The relationships among the Neotropical Diplotaxini and homology of revised and new taxa are revisited with parsimony analyses based on morphological characters, and probabilistic analyses based on concatenated ITS2 and COI genes. Neotropical Diplotaxini is now composed of five monophyletic genera: Pacuvia, Pachrodema, Homalochilus, Liogenys, and Careocallus gen. nov.. Pseudodiplotaxis is here transferred to incertae sedis of Melolonthinae. Careocallus is the sister genus of Liogenys and is composed of Careocallus tehuelche sp. nov. and Careocallus densicollis sp. nov. Sister phylogenetic relationship between Homalochilus and the rest of genera except Pacuvia is revealed. Homalochilussensu nov. is comprised by Homalochilus punctatostriatus and Homalochilus nigripennis sp. nov. This genus recovered its monophyly by transferring Homalochilus niger to Liogenys, as Liogenys nigercomb. nov. and this name is also synonymized with L. morio. The type species of Homalochilus is emended to be H. punctatostriatus. A neotype (Liogenys morio) and lectotypes (H. punctatostriatus, H. niger) are designated. Dichotomious key to Neotropical Diplotaxini genera and to species of Homalochilus and Careocallus are presented. Sequences and phylogenetic signals for Neotropical melolonthines are reported for the first time.