Igor Orlov:
Phylogenetic tools to improve systematics of Aleocharinae rove beetles (Staphylinidae), from subantarctic Leptusa to the entire subfamily

Date: 31-01-2019    Supervisor: Alexey Solodovnikov

The thesis is devoted to the phylogenetic systematics of Aleocharinae, the largest subfamily of rove beetles (Staphylinidae) with poorly developed systematics at all taxonomic levels. Aleocharines are very common in the ground-based habitats in all habitable terrestrial biotopes of our planet. Some of them are highly specialised and unusual, for example the numerous myrmecophilous and termitophilous Aleocharinae. Because of the species richness and ecological diversity Aleocharinae can be used as models in various biodiversity-related studies. As an example, the first chapter of my thesis uses aleocharines from the genus Leptusa to address questions of biogeography of the Subantarctic islands. These remote islands pose biogeographic puzzles which can be explored through the phylogenetic and distribution patterns displayed by their inhabitants. My revision of Subantarctic Leptusa eliminates earlier confusions and reveals new species of this genus from these islands. A phylogeny-based attempt to understand their biogeography demonstrates the need for a robust phylogenetic knowledge of the subfamily as a whole because, for example, monophyly or composition of large genera like Leptusa are unclear of the world basis. The second chapter of the thesis attempts such broader improvement for the entire subfamily. It provides an overall review of the main phylogenetic and systematic problems for all tribes of Aleocharinae and a detailed and well illustrated morphological dataset across the subfamily, the first of this kind. A series of phylogenetic analyses performed in that chapter using the originally developed morphological dataset and earlier published DNA sequences from multiple loci, show that the total evidence analysis combining both types of data is the most efficient and desirable way to reconstruct the large scale phylogeny of Aleocharinae. In particular, my thesis shows how such total evidence approach can handle species for which molecular data are not available, a usual constraint in the modern phylogenetic systematics. Altogether, both chapters include phylogenetic work at various taxonomic levels, from species to tribes. While at the lower taxonomic level, for the Subantarctic Leptusa, all necessary new taxa are described and other taxonomic changes implemented, limited taxon sampling of the phylogenetic analysis of the entire subfamily Aleocharinae leaves it as an exploratory stepping-stone towards desired more comprehensive work.