The males of both species of the paper wasp genus Nectarinella Bequaert, N. xavantinensis Mateus & Noll and N. championi (Dover), are described, and the genitalia illustrated. These are compared to species in the closely related genera Chartergellus, Leipomeles, Marimbonda, Parachartergus and Pseudopolybia.
Epiponini; male genitalia; Polistinae; taxonomy; Vespidae
