Key to the Central American species of Nymphister

1. Dorsal surface smooth and shiny; longitudinal discal striae of metaventrite absent, inner lateral striae of metaventrite represented only by recurrent arms.............................................. N. monotonus (Reichensperger, 1935)

- Dorsal surface with fine alutaceous microsulpture; longitudinal discal striae and inner lateral striae of metaventrite complete..................................................................................................... 2

2. Elytral surface smooth, without any punctures............................... N. simplicissimus Reichensperger, 1933

- Elytral surface with numerous shallow, circular, postobsolete (puncture rims broken and excavations level posteriorly) punctures, irregularly tracing course of 2–5th dorsal and sutural striae................................ N. rettenmeyeri sp. n.