Cecidomyiidae (Diptera) on Myrtaceae in Brazil: richness and geographic distribution.

Myrtaceae have a wide geographical distribution in Brazil and host a great richness of Cecidomyiidae galls. However, the number of cecidomyiid species on them has not yet been established and the knowledge of their geographic distribution is deficient. We provide the first list of cecidomyiid species on Myrtaceae and analyze their distribution in Brazilian biomes. A literature review was performed and new data were obtained from herbarium specimens of the Jardim Botânico do Rio de Janeiro. In Brazil, 13 species of Myrtaceae of five genera shelter described species of gall midges. Eugenia hosts the greatest richness of gall-inducers. All plant species have human uses and are native to Brazil, being seven endemic. Myrtaceae shelter 25 cecidomyiid species of 13 genera in 25 gall morphotypes. Sixteen species occur on endemic hosts, highlighting the peculiarity of the Brazilian fauna. These Cecidomyiidae occur collectively in five biomes, but most species (92%) are known from the Atlantic Forest, where 72% appear exclusively. Sixty per cent are restricted to a single Brazilian state, indicating their still poorly known distribution.