Metopius soror Chiu, 1962 was originally described based on a single female. This study reports the host record of M. soror on Nyctemera albofasciata (Wileman, 1911) for the first time and female oviposition behavior on the larva of N. adversata (Schaller, 1788). We also provide the first description of the male of M. soror.
Additional records of the genus Atholus from Taiwan are provided based on the museum and private collections in Taiwan and Japan. Eight species of the genus Atholus are recorded and distributed in Taiwan, with specimens of six species examined in this study. The key to Taiwanese species of Atholus is provided, and the illustrations of male 9th, 10th tergites, and 9th sternum of Atholus levis Mazur and A. confinis (Erichson) are published for the first time.