Australian species of the genus Opius Wesmael (Hymenoptera : Braconidae) attacking leaf-mining Agromyzidae, with the description of a new species from South-east Asia

The species of Opius Wesmael that attack leaf-mining Agromyzidae in Australia are discussed, and a key provided for their separation. Opius cinerariae Fischer is redescribed based on specimens reared from Liriomyza chenopodii (Watt) (Agromyzidae), and its subgeneric placement is discussed in light of newly discovered morphological features. Opius (Opiothorax) chromatomyiae Belokobylskij & Wharton sp. n. is described from specimens reared from Chromatomyia horticola (Goureau) and Liriomyza huidobrensis (Blanchard) (Agromyzidae) in Malaysia, Indonesia and Vietnam. Opius insulicola Tobias nom. n. is proposed for Opius insularis (1998), a junior primary homonym.