Phylogeny of Hydrophiloidea (Coleoptera: Staphyliniformia) using characters from adult and preimaginal stages

A phylogenetic analysis using characters from egg cases, larvae, pupae and adults was conducted; the outgroups included the beetle families Silphidae, Hydraenidae and Histeridae. Characters from the immature stages were obtained mostly from material reared in the laboratory, those from the adults were obtained from Hansen's generic revision for the superfamily. The results support the position of Hydraenidae within the Staphylinoidea, and not as part of Hydrophiloidea; Histeroidea is proposed as the sister group of Hydrophiloidea. At family level two clades are distinguished; the relationships within the first clade are ((Georissidae Epimetopidae) Helophoridae), those within the second are ((Hydrophilidae Spercheidae) Hydrochidae). Larval characters were most informative at the base of the tree, especially those associated with the spiracular atrium; adult characters were most informative at the apex of the tree.