Contribution to the genus Balcha Walker (Hymenoptera, Chalcidoidea, Eupelmidae) of China, with description of a new species and DNA data.

Eight species of Balcha Walker (Hymenoptera, Chalcidoidea, Eupelmidae) are reported from China, including one new species, B. fulgida Wang & Peng, sp. nov., and three newly recorded species: B. indica (Mani & Kaul, 1973), B. laciniosa Gibson, 2005, and B. reticulata (Nikol'skaya, 1952). An identification key to the eight Chinese species and the mitochondrial cytochrome c oxidase subunit I (COI) gene sequences for B. dictyota Gibson, 2005, B. indica, and the new species are provided. Furthermore, morphological, molecular, and host distribution lines of evidence indicate that the Nearctic population of B. indica, a parasitoid of the emerald ash borer, Agrilus planipennis Fairmaire, 1888 (Coleoptera, Buprestidae), most likely originated from China rather than from Southeast Asia as previously hypothesized. In addition, extensive intraspecific morphological variation within B. dictyota are documented and new host associations reported for B. indica and B. reticulata.