The new subgenus Maculergithus subgen. nov. is established to accommodate two new species of the genus Gergithus Stål, 1870 (Issinae, Hemisphaeriini): G. (Maculergithus) tamdao subgen. et sp. nov. and G. (Maculergithus) luteomaculatus subgen. et sp. nov. from Tam Dao National Park in North Vietnam. Two more species from Hainan, China, G. multipunctatus Che, Zhang & Wang, 2007 and G. nonomaculatus Meng & Wang, 2012 are also placed in Maculergithus subgen. nov. A fifth species from Hainan, yet undescribed and erroneously identified as G. multipunctatus in recent papers also belongs to this new subgenus. Illustrations of habitus, morphological details and male genitalia together with a distribution map and an identification key to the species of Maculergithus subgen. nov. are provided. Four species of the genus Gergithus are now recorded in Vietnam. A rectificative note on the misinterpretation of G. multipunctatus in recent publications on Issidae is also provided.
Global Taxonomic Initiative, Tonkin, planthopper, Fulgoroidea, China.