Systematics of the braconid wasp subfamily Rhysipolinae (Hymenoptera, Braconidae) based on UCE data, with the description of a new Neotropical genus.

Abstract

Rhysipolinae is a small cosmopolitan cyclostome subfamily of braconid wasps, currently comprising 10 genera and more than 80 species. The two species of the subfamily whose biology has been confirmed are koinobiont ectoparasitoids of lepidopteran larvae, deviating from the two common parasitoid strategies in Braconidae (koinobiont-endoparasitoid, idiobiont-ectoparasitoid). Defining the limits of Rhysipolinae has been challenging due to the lack of exclusive morphological features and difficulties in resolving its phylogenetic relationships based on both morphological and Sanger DNA sequence data. However, recent phylogenomic studies using nuclear ultraconserved elements (UCEs) and mitochondrial genome sequences have begun to clarify its relationships, although various generic boundaries remain unclear. Here a phylogenomic analysis based on UCE data was performed including 32 species of nine rhysipoline genera to assess the monophyly of the subfamily as well as its generic limits. Our phylogenetic analysis confirmed the monophyly of Rhysipolinae, but no unique external morphological features were found for its diagnosis. Most genera were recovered as monophyletic except Rhysipolis Förster, 1863, whose clade included Cerophanes Tobias, 1971 and Troporhysipolis Quicke, Belokobylskij & Butcher, 2016. Based on our molecular and morphological evidence, we synonymise Cerophanes syn. nov. with Rhysipolis and describe the new genus and species Rogapolisnomai García-Acosta, Shimbori, Castañeda-Osorio & Zaldívar-Riverón gen. et sp. nov., which is mainly characterised by a median longitudinal carina on the second metasomal tergum, a feature previously predominantly occurring in Rogadinae. Moreover, Pseudavga Tobias, 1964 syn. nov. is proposed as a subgenus of Pachystigmus Hellén, 1927. A taxonomic diagnosis for Rhysipolinae and a key to its currently valid genera are also provided.