On the phylogeny of the Dytiscidae (Insecta : Coleoptera) with emphasis onthe morphology of the female reproductive system

Characters from adult morphology are analyzed cladistically to infer the ph ylogeny of the family Dytiscidae. The analysis is based on examination of 2 33 species of Dytiscidae and several outgroup taxa including members of Not eridae, Amphizoidae, Hygrobiidae and Carabidae. Members of all currently re cognized tribes of Dytiscidae are represented except Anisomeriini Brinck, H ydronebriini Guignot and Carabhydrini Watts. Emphasis is placed on identify ing informative characters from the female genital system that comprise 34 of the resulting 101 total characters. The consensus of the most parsimonio us trees is well resolved and supports recognition of ten subfamilies of Dy tiscidae including; Matinae van den Branden, Laccophilinae Gistel, Coptotom inae van den Branden, Copelatinae Erichson, Hydroporinae Aube, Agabinae Tho mson, Colymbetinae Erichson, Lancetinae van den Branden and Dytiscinae Leac h. Also, Hydrodytes Miller, NEW GENUS, is erected and placed in its own sub family, Hydrodytinae, NEW SUBFAMILY, to include two species previously plac ed in Agaporomorphus Zimmermann (Copelatinae), H. opalinus (Zimmermann) (NE W COMBINATION) and H. dodgei (Young) (NEW COMBINATION). Hydrodytinae is sis ter group to Hydroporinae and is diagnosed by the presence of anterior apod emes on the gonocoxae, several characters of the metendosternite teach syna pomorphic with Hydroporinae), lack of pseudotetramerous pro- and mesotarsi, lack of a declivitous prosternum and prosternal process, the scutellum vis ible with the elytra closed (all plesiomorphic), the rami of the female gen italia sinuate and dorsally with an opalescent sheen teach autapomorphic fo r Hydrodytinae). Matinae is resolved as the sister group to the remaining D ytiscidae. Hyphydrini Sharp is found to be paraphyletic with respect to Pac hydrini Bistrom, Nilsson and Wewalka, and the latter is relegated to a juni or subjective synonym of the former (NEW SYNONYMY). Hydroporini Aube and Hy grotini Portevin are found to be para- or polyphyletic. No changes are made to the classification of these taxa since character evidence is relatively weak, and taxon sampling within Hydroporinae is inadequate to justify chan ges. Carabdytes Balke, Hendrich and Wewalka is found to be the sister taxon to the remaining Colymbetinae, and because of its unique combination of ch aracters and phylogenetic placement it is included in its own tribe, Carabd ytini Pederzani (RESURRECTED). All other examined tribes of Dytiscidae are monophyletic. The female genitalia are described and figured for numerous t axa across the family, and numerous other characters are described and figu red. The evolution of various features of the female genitalia within Dytis cidae is discussed. The resulting phylogenetic hypothesis is compared and c ontrasted with other phylogenetic proposals.