Integrative taxonomy: molecular phylogenetics of Polypedilum (Cerobregma) and revisited morphology of Yaethauma and Collartomyia (Diptera: Chironomidae) reveals synonymy and supports new classification

Abstract

A recently described genus of Chironomini, Yaethauma, is newly associated with a pupa that resembles those in Polypedilum subgenus Cerobregma. We derived molecular evidence from six concatenated markers from five loci (18S, 28S, CAD1, CAD4, COI-5P, -3P) of Yaethauma longiligulatum, six species of Polypedilum (Cerobregma), ingroup Polypedilum (representing six other subgenera) and appropriate outgroups. Mixed-model Bayesian inference and maximum likelihood strongly supports (PP = 0.97, BS = 99) Yaethauma belonging to Polypedilum, as sister to a monophyletic subgenus Cerobregma. Integration of morphology of the male and pupa of Yaethauma if corroborated with the molecular evidence, thus we synonymize Yaethauma (type species Yaethauma longiligulatum) with Polypedilum type species Polypedilum pelostolum (= Chironomus nubifer). Although molecular material of Afrotropical Collartomyia is lacking, when it is integrated into morphological analyses, its inclusion in Polypedilum near Cerobregma is well supported. Implementation of this creates further new synonymies with the subjective taxonomic conclusion that Collartomyia (type species Collartomyia hirsuta) is also a junior synonym of Polypedilum and a senior synonym of Polypedilum (Cerobregma). Within Polypedilum only the subgenera Collartomyia subgen. nov. and Tripodura are recovered as monophyletic groups; the other subgenera are not monophyletic. The larvae of these chironomids often feed within retreats of hydropsychid caddisflies (Trichoptera), with commensurate morphological modifications in all life stages.