Two new species of Liodessus diving beetles from Costa Rica (Coleoptera, Dytiscidae, Bidessini)

Two new species of the diving beetle genus Liodessus Guignot, 1939 are described from Costa Rica: Liodessus quetzalicus sp. nov. (central valley as well as the high-mountain Páramo region, 1,380–2,800 m) and L. cerrodelamuerte sp. nov. (> 3,000 m).

The species are delineated based on morphological characters, including male genitalia as well as beetle size, shape and colour pattern. The habitats are described in detail. Altogether 18 species and 10 additional subspecies of Liodessus are now recorded from higher mountain regions in Central and South America.