PhylogenyBlackwell Publishing Ltd and classification of diving in the tribe (Coleoptera, , )

KELLY B. MILLER, JOHANNES BERGSTEN & MICHAEL F. WHITING

Accepted: 25 July 2006 Miller, K. B., Bergsten, J. & Whiting, M. F. (2007). Phylogeny and classificaiton of diving beetles doi:10.1111/j.1463-6409.2006.00254.x in the tribe Cybistrini (Coleoptera, Dytiscidae, Dytiscinae). — Zoologica Scripta, 36, 41–59. Phylogenetic relationships among members of the diving tribe Cybistrini (Coleoptera: Dytiscidae) were inferred from analysis of 47 adult and larval morphological characters and sequences from portions of the genes cytochrome oxidase I (COI) and II (COII), histone III (H3) and wingless. Thirty-three species of Cybistrini were included, representing all -groups except Regimbartina Chatanay and (Bifurcitus) Brinck, and most historically recog- nized species groups and subgenera used in the tribe. Outgroups include six species from other tribes within Dytiscinae and Lancetinae. Analyses included parsimony analysis of the com- bined data, likelihood analysis of combined molecular data and partitioned Bayesian analysis of the combined data. Results indicate that Cybistrini is well supported as a monophyletic group. Within the tribe, all currently recognized genus groups were found to be monophyletic with the exception of Onychohydrus Schaum, which is paraphyletic with respect to Austrodytes Watts in the parsimony analysis, but monophyletic in the likelihood and Bayesian analyses, and sensu stricto, which is paraphyletic with respect to C. (Melanectes) Brinck and C. (Scaphinectes) Ádám in the parsimony analysis or only the latter in the likelihood and Bayesian analyses. Results also suggest that some, but not all, historically recognized species groups or subgenera in the large genus Cybister Curtis are monophyletic, and this is discussed and compared. To improve the classification, the name Sternhydrus Brinck is elevated from sub- genus to genus rank (new status). Four subgenera in the genus Cybister are recognized: C. (Melanectes) Brinck, C. (Megadytoides) Brinck (resurrected), C. (Neocybister) Miller, Bergsten and Whiting (new subgenus) and C. (Cybister) Curtis. The following new synonyms are established: Trochalus Dejean (new synonym), and Scaphinectes Ádám = Cybister (Cybister) (new synonym). The Neotropical species Cybister parvus Trémouilles (not examined) apparently does not fit any historical or currently recognized genus-group diagnosis in Cybistrini, so it is retained in Cybister but incertae sedis with respect to subgenus. In addition to classification, the evolution of the unique character combinations present in cybistrines are discussed. A key to the adults of genera and subgenera is presented. Kelly B. Miller, Department of Integrative Biology, Brigham Young University, Provo, UT 84602 USA and Department of Biology, University of New Mexico, 167 Castetter Hall, MSC03 2020, Albuquerque, NM 87131-0001, USA. E-mail: [email protected] Johannes Bergsten, Department of Entomology, Natural History Museum, Cromwell Road, London SW7 5BD and Division of Biology, Imperial College London, Silwood Park Campus, Ascot SL5 7PY, UK. E-mail: [email protected] Michael F. Whiting, Department of Integrative Biology, Brigham Young University, Provo, UT 84602, USA. E-mail: [email protected]

Introduction The only aquatic beetles that approach the size of large Members of the tribe Cybistrini (Dytiscidae: Dytiscinae) are Cybistrini are members of the related dytiscine genus conspicuous components of the water beetle fauna through- Linnaeus and species of Hydrophili