Descriptions of two new species of Platygaster Latreille that attack gall midges (Diptera, Cecidomyiidae) with notes on their biology (Hymenoptera, Platygastridae).

Platygaster ingeniosus Matsuo & Yamagishi, sp. n. and P. urniphila Matsuo & Yamagishi, sp. n. (Hymenoptera: Platygastridae) are described from Japan. The former species is an egg-larval solitary parasitoid of Masakimyia pustulae Yukawa and Sunose (Diptera: Cecidomyiidae). The latter species is an egg-larval gregarious parasitoid of Rhopalomyia longitubifex (Shinji) (Diptera: Cecidomyiidae).