Notes on the genus Rhantus Lacordaire (Coleoptera: Dytiscidae) in New Zealand

Abstract

The diving beetle genus Rhantus Lacordaire includes over 80 species and has an almost worldwide distribution. Three species are known to occur in the New Zealand region, one of which, R. suturalis Macleay, occurs very widely and is found through most of the Old World from New Zealand to Southern and Central Europe. The other two species have much more limited distributions, as they are relatively rare New Zealand endemics.

The purpose of this note is to describe the current status of the three species in New Zealand. There has been some confusion in the New Zealand literature over the correct name and distribution of R. suturalis, which I attempt to clarify here. An additional locality is recorded for R. plantaris Sharp. The conservation status of both R. plantaris and R. schauinslandi Ordish is discussed.