Rhantus procul sp. nov., a new diving beetle from Central Sulawesi – sister to a species from Sri Lanka (Coleoptera, Dytiscidae, Colymbetinae)

The diving beetle Rhantus procul sp. nov. is described from around 2,000 m a. s. l. at Mount Pompangeo in Central Sulawesi, Indonesia. Besides Rhantus suturalis (W. S. Macleay, 1825) it is the second species of the genus recorded from Sulawesi. Altogether nine species of the genus are now known from Indonesia.

The median lobe of the new species is very similar to Rhantus interclusus (Walker, 1858), endemic to the highlands of Sri Lanka, but the species can be easily distinguished by body size, coloration of the pronotum and the slightly different curvature of median lobe.