Abstract
Six Japanese species belonging to the genus Aridelus Marshall, 1898 (Hymenoptera, Braconidae) were recorded and photographed. Three species, A.dubius Belokobylskij, A.egregius Schmiedeknecht and A.rufotestaceus Tobias (= Aridelusrufiventris Luo & Chen syn. nov.), are new to Japan, and a new species, A.rutilipoides sp. nov. is described. An identification key to the Japanese species of Aridelus is also provided. In addition, new host records are provided, i.e., A.flavicans Chao reared from Homoeocerusunipunctatus and Riptortuspedestris (Alydidae) and A.rufotestaceus reared from Glauciassubpunctatus (Pentatomidae). The Alydidae is a newly recorded host family of Aridelus.