Addenda to the Revisions of the Genera Gergithus Stål and Hemisphaerius Schaum (Hemiptera, Auchenorrhyncha, Fulgoroidea: Issidae)

The genus Gnezdilovius Meng, Webb et Wang, 2017 is revised. Maculergithus Constant et Pham, 2016, which was described as a subgenus of Gergithus Stål, 1870, is upgraded to a genus. Ishiharanus Hori, 1969 is reinstalled from synonymy with Gergithus and considered a valid name. Two new genera are erected, Ceratogergithus Gnezdilov, gen. n. (type species: Gergithus spinosus Che, Zhang et Wang, 2007) and Ophthalmosphaerius Gnezdilov, gen. n. (type species: Hernisphaerius trilobulus Che, Zhang et Wang, 2006). Hernisphaerius bistriatus Schumacher, 1915, Gergithus carbonarius Melichar, 1906, G. rosticus Chan et Yang, 1994, G. nummarius Chan et Yang, 1994, and G. rotundus Chan et Yang, 1994 are transferred to the genus Epyhemisphaerius Chan et Yang, 1994, Gergithus quinquemaculatus Che, Zhang, Wang, 2007—to the genus Maculergithus , Gergithus chelatus Che, Zhang, Wang, 2007 and G. pseudotessellatus Che, Zhang, Wang, 2007—to the genus Ceratogergithus , Hernisphaerius binocularis Chen, Zhang, Chang, 2014—to the genus Ophthalmosphaerius , and Gergithus robustus hoozanensis Schumacher, 1915—to the genus Gnezdilovius . The male genitalia of Gergithus herbaceus (Kirby, 1891) and Hernisphaerius interclusus Noualhier, 1896 are illustrated for the first time.