Borneodessus zetteli, new genus and new species, notes on biogeography and a checklist of Dytiscidae from Borneo (Insecta: Coleoptera: Dytiscidae)

Abstract

A new genus of Dytiscidae, Borneodessus gen. n., is described for Borneodessus zetteli zetteli sp. n. (Sabah, East Malaysia) and Borneodessus zetteli kalimantanensis ssp. n. (East Kalimantan, Indonesia). The new genus belongs to the tribe Bidessini because of the presence of two-segmented parameres of the aedeagus. A modified male clypeus is an apomorphy for Borneodessus zetteli. The species habitually resembles some species of Africodytes Biström, 1988 (Africa), Amarodytes Régimbart, 1900 (South America), and some Clypeodytes Régimbart, 1894 (Old World tropics). However, a sister group relation or closer affinities to any of the genera of Bidessini could not be established. Borneodessus is so far the first genus of Dytiscidae which is endemic to Borneo, but we suggest a certain probability of its occurrence in other Sundaic areas. The species is a rheobiont, being collected from forest streams. We briefly address biogeographical aspects and provide a checklist of Bornean Dytiscidae, indicating the currently known degree of endemism.

Keywords:

• Insecta
• Coleoptera
• Dytiscidae
• Diving Beetle
• Borneodessus
• New Genus
• New Species
• Borneo
• Biogeography
• Checklist