An opiine Braconidae (Hymenoptera) reared from Richardiidae (Diptera) and recognition of a new species group of Opius s. l.

A new species of opiine Braconidae, Opius rojam Daniels & Wharton, is described from Trinidad. The description is based in part on two individuals reared from Sepsisoma erythrocephalum infesting shoots of the grass Paspalum fasciculatum. This is the first record of members of the Opiinae attacking species in the dipteran family Richardiidae. The Opius ingenticornis species group is proposed and delineated to accommodate this and several putatively related species formerly included in Opius (Merotrachys), Opius (Pendopius), and Opius (Ilicopius). A key to the species of this group is provided. Descriptions and diagnoses are referenced to the Hymenoptera Anatomy Ontology.