Abstract
This is the first part in a series of three papers which revise the seven species of the flower bug genus Orius WOLFF occurring in Japan and Taiwan. Herein two new species representing two new subgenera, Orius (Xylorius) miyamotoi from Kyushu, Japan and O. (Trichorius) atratus from the Ryukyus and Taiwan, are diagnosed, described and illustrated. General morphology and taxonomic characters are discussed.