The phylogenetics and higher (family-group) classifi cation of extant

members of the beetle family Dytiscidae (Coleoptera), or predaceous diving beetles,

is reviewed and reassessed. A phylogenetic analysis of the family is presented based

on 168 species of diving beetles and 9 outgroup taxa from Gyrinidae, Noteridae,

Amphizoidae and Paelobiidae. All currently recognized dytiscid subfamilies and

tribes are represented, most by multiple genera and species. Data include 104 morphological

characters and approximately 6,700 aligned bases from 9 DNA sequence

fragments from cytochrome c oxidase I  (COI) and II  (COII), histone III  (H3), 16S

rRNA  (16S), 12S rRNA  (12S), arginine kinase  (argkin), RNA polymerase II  (RNA

pol II), elongation factor 1 alpha  (Ef1α ), and wingless  (wnt). Parsimony and

Bayesian analyses were conducted. The topology of the parsimony tree (consensus

of 13 equally parsimonious solutions) exhibits numerous anomalies inconsistent

with convincing morphological features and the Bayesian results and has,

generally, relatively poor bootstrap support for major clades. The Bayesian topology

is more consistent with major morphological features and has strong support 

 for most clades, and conclusions are based primarily on this estimate. Major

higher-level phylogenetic relationships with strong support include: (1) monophyly

of Dytiscidae Leach, (2) Matinae Branden sister to the rest of Dytiscidae,

(3) Agabinae Thomson + Colymbetinae Erichson, (4) Hydrodytinae

Miller + Hydroporinae Aubé, (5) Dytiscinae Leach + Laccophilinae Gistel +

Cybistrini Sharp + Copelatinae Branden, (6) monophyly of the subfamilies Matinae,

Colymbetinae, Copelatinae, Coptotominae Branden, Lancetinae Branden,

Laccophilinae (including Agabetes  Crotch), Agabinae (support weaker than in other

subfamilies) and Hydroporinae (monophyly of Hydrodytinae not tested), (7) paraphyly

of Dytiscinae with Cybistrini sister to Laccophilinae (with strong support)

and this clade sister to other Dytiscinae, and (8) monophyly of both Agabini

( Agabus  -group of genera) and Hydrotrupini Roughley ( Hydrotrupes  Sharp and the

Platynectes  -group of genera). Major conclusions regarding tribes within

Hydroporinae include: (1) monophyly of the tribes Vatellini Sharp, Methlini

Branden, Hydrovatini Sharp, Hygrotini Portevin, Hyphydrini Gistel (without

Pachydrus  Sharp) and Bidessini Sharp (including Peschetius  Guignot, Hydrodessus

 J. Balfour-Browne and Amarodytes  Régimbart) (monophyly of Laccornini

Wolfe and Roughley and Pachydrini Biström, Nilsson and Wewalka not tested),

(2) Pachydrini is a problematic, long-branched taxa resolved here as sister to

Hydrovatini but with weak support, (3) Hydroporini monophyletic except for

Laccornellus  Roughley and Wolfe and Canthyporus  Zimmermann, (4) Laccornellus

 and Canthyporus  together monophyletic and sister to Hydroporinae except

Laccornini. Four groups are resolved within Hydroporini exclusive of

Laccornellus  + Canthyporus  corresponding to the Deronectes  -, the Graptodytes  -,

the Necterosoma  - and the Hydroporus  -groups of genera. The classifi cation of

Dytiscidae is revised with the following taxonomic changes: (1) Hydrotrupini is

recognized as a tribe of Agabinae including the genus Hydrotrupes  and the

Platynectes  -group of genera ( new status  ), (2) the genus Rugosus  García is moved

from Colymbetinae to Copelatinae ( new placement  ), (3) Cybistrini is elevated

from tribe rank within Dytiscinae to subfamily of Dytiscidae ( new rank  ), (4)

Hyderodini Miller is placed as a junior synonym of Dytiscini ( new synonymy  ), (5)

Laccornellus  and Canthyporus  are removed from Hydroporini and placed in their

own tribe, Laccornellini ( new tribe  ), (6) the following family group names are

resurrected from synonymy with Hydroporini and placed as subtribes within

Hydroporini, Deronectina Galewski (for the Deronectes  -group of genera, new

status  ), Siettitiina Smrž (for the Graptodytes  -group of genera, new status  ),

Sternopriscina Branden (for the Necterosoma  -group of genera, new status  ), and

Hydroporina (for the Hydroporus  -group of genera, new status  ), (7) Carabhydrini

Watts is placed as a junior synonym of Sternopriscina ( new synonymy  ), and

(8) Hydrodessus  , formerly incerta sedis  with respect to tribe, is placed in Bidessini

( new placement  ). Each subfamily, tribe and subtribe is diagnosed and its taxonomic

history discussed.