A new species of the Tatargina Butler, T. erythromelaena Bayarsaikhan Bae, n. sp., is described from Cambodia, with a recorded species, T. picta (Walker). Illustrations of adults and male genitalia of Cambodia and Thailand species are presented.
Keywords: Lepidoptera, Lithosiini, Tatargina picta, T. erythromelaena, taxonomy, distribution.