A new species of Machaeriobia Rübsaamen, 1915 (Diptera, Cecidomyiidae) from Brazil

A new species of Machaeriobia Rübsaamen, 1915 (Diptera: Cecidomyiidae) from Brazil. Machaeriobia Rübsaamen, 1915 is a Neotropical genus, until now known from a single species, M. machaerii (Kieffer, 1913), described from Brazil (State of Santa Catarina). That species induces spherical leaf galls on Machaerium sp. (Fabaceae) and its geographical distribution is still restricted to the type-locality. A new galling species, Machaeriobia gemmae, associated with Machaerium macaense (Fabaceae), is described and illustrated (larva, pupa, male, and female) based on material collected in the Parque Nacional da Serra dos Órgãos (State of Rio de Janeiro, Brazil). The new species is unique for its one or two-segmented palpi, deeply notched aedeagus, pupa with free dorsal abdominal spines, larva with reduced spatula and two apically sclerotized terminal lobes. We synonymize Anadiplosis Tavares, 1916 under Machaeriobia Rübsaamen, 1915. Six wasp species (Hymenoptera) are associated with the galler: Tanaostigmodes carinatus La Salle 1987 and Tanaostigmodes sp. (Tanaostigmatidae), Galeopsomyia sp. (Eulophidae), Calorylea sp. (Eurytomidae), and two undetermined species of Eurytomidae.