摘要

Species of the genus Arocatus Spinola, 1837 (Hemiptera: Heteroptera: Lygaeidae: Lygaeinae) occurring in Taiwan are reviewed, illustrated and keyed. Arocatus elegantulus sp. nov. is described; earlier records of Caenocoris dimidiatus Breddin, 1907 from Taiwan and the Ryukyu Archipelago of Japan pertain to this new species. Arocatus pseudosericans Gao, Kondorosy & Bu, 2013 and A. nanus (Breddin, 1900) are recorded for the first time from Taiwan; earlier records of A. sericans (Stal, 1859) pertain to A. pseudosericans. The distribution of A. sericans and A. pseudosericans in Japan and Korea and the intraspecific variability of A. pseudosericans are discussed. The identification problems of the genera Arocatus, Caenocoris Fieber, 1860 and Thunbergia Horvath, 1914 are highlighted, the external male genitalia of T. cf. marginata (Thunberg, 1822) are described and illustrated, and diagnostic characters potentially suitable for distinguishing Thunbergia from Arocatus are provided.