Molecular phylogeny and diversification of the “Haenydra” lineage (Hydraenidae, genus Hydraena), a north-Mediterranean endemic-rich group of rheophilic Coleoptera

► Phylogeny of a speciose lineage of water beetles (“Haenydra”) was reconstructed. ► Molecular clock was used to date the diversification of clades within “Haenydra”. ► Geographic structure of the main clades within “Haenydra” was investigated.