Cladistic analysis of the tribes of Dytiscinae and the phylogenetic position of the genus Notaticus Zimmermann (Coleoptera : Dytiscidae)

A hypothesis of the phylogeny of the tribes of Dytiscinae is presented base d on a cladistic analysis of adult morphological characters. All tribes of Dytiscinae were included with larger tribes represented by multiple genera. Outgroups included members of all major lineages (subfamilies) of Dytiscid ae. The matrix consists of 22 taxa and 45 characters. A single most parsimo nious cladogram was produced by the analysis. It is concluded from the anal ysis that Dytiscinae is paraphyletic with respect to the genus Notaticus Zi mmermann which has been previously recognized as the only member of the sub family Aubehydrinae. Its position within the subfamily requires that it be placed within its own tribe, Aubehydrini. Additionally, Dytiscini was found to be paraphyletic, and a new tribe, Hyderodini, is proposed to contain th e genus Hyderodes Sharp. Dytiscini is restricted to include only the genus Dytiscus Linneaus. Dytiscinae and all other tribes within the subfamily wer e found to be monophyletic. The proposed relationships of the tribes of Dyt iscinae are Cybistrini + (Dytiscini + (Hyderodini + (Aubehydrini +(Hydatici ni +(Eretini + Aciliini))))). Characters discovered to be useful for phylog enetic analysis of the subfamily are illustrated and described. The tribes are diagnosed and a key is presented for distinguishing them.