First records of three genera of Metopiinae (Hymenoptera, Ichneumonidae) from South Korea with description of one new species

Trieces koreanus Choi & Lee, sp. nov. is described and illustrated in the South Korean fauna. The genera Periope, Stethoncus, and Trieces are recorded for the first time from South Korea. Description with photographs of the new species and diagnoses for each species are provided.