Validation of Rhabditolaimus Fuchs, 1914 (Nematoda: Diplogastridae) supported by integrative taxonomic evidence

Abstract

Rhabditolaimus leuckarti, type species of Rhabditolaimus, was isolated from its type host, Hylobius abietis (Coleoptera: Curculionidae), at several locations in central Europe. The position of the species among other diplogastrid nematodes was revised using morphological characters and molecular phylogenetic analysis. The revealed common apomorphic features and the inferred evolutionary tree strongly indicates a close relationship between R. leuckarti and Myctolaimus. Our findings suggest that the historical classifications do not reflect the natural relationships of some diplogastrid taxa. Therefore, we reject all previous synonymisations of Rhabditolaimus and consider it to be valid within the Diplogastridae. Five species are transferred from Diplogasteroides to Rhabditolaimus. Myctolaimus sensu lato is regarded as a junior synonym of Rhabditolaimus and the following new combinations are proposed: R. anoplophorae comb. n., R. carolinensis comb. n., R. curzii comb. n., R. dendrophilus comb. n., R. erectus comb. n., R. goodeyi comb. n., R. inevectus, comb. n., R. kishtwarensis comb. n., R. macrolaimus comb. n., R. nacogdochensis comb. n., R. neolongistoma comb. n., R. pellucidus comb. n., R. platypi comb. n., R. rifflei comb. n., R. robiniae comb. n., R. ulmi comb. n., R. vitautasi comb. n., R. walkeri comb. n. and R. zamithi comb. n.