The Eastern common groundhopper, Tetrix japonica, is a pygmy grasshopper species widely distributed in the Eastern Palearctic region, and shows a high degree of phenotypic variation. The classification of Tetrix japonica is difficult and frequently involved errors. Among the many species of Tetrigidae that have been described in China within the last decades, many synonyms of Tetrix japonica were found. The type specimens of many species deposited in the Chinese museums have been re-examined and as a result, Tetrix japonica is systematically revised. Based on the results of this review, 23 new synonyms of Tetrix japonica are proposed: Coptotettix circinihumerus Zheng & Deng, 2004, syn. nov.; Coptotettix emeiensis Zheng, Lin & Zhang, 2012, syn. nov.; Euparatettix rongshuiensis Zheng, 2005, syn. nov.; Euparatettix zayuensis Zheng, Zeng & Ou, 2011, syn. nov.; Macromotettix nigritubercle Zheng & Jiang, 2006, syn. nov.; Macromotettix yaoshanensis Zheng & Jiang, 2000, syn. nov.; Tetrix albistriatus Yao & Zheng, 2006, syn. nov.; Tetrix albomaculatus Zheng & Jiang, 2006, syn. nov.; Tetrix albomarginis Zheng & Nie, 2005, syn. nov.; Tetrix cenwanglaoshana Zheng, Jiang & Liu, 2005, syn. nov.; Tetrix cliva Zheng & Deng, 2004, syn. nov.; Tetrix duolunensis Zheng, 1996, syn. nov.; Tetrix grossovalva Zheng, 1994, syn. nov.; Tetrix jiuwanshanensis Zheng, 2005, syn. nov.; Tetrix latipalpa Cao & Zheng, 2011, syn. nov.; Tetrix liuwanshanensis Deng, Zheng & Wei, 2007, syn. nov.; Tetrix qinlingensis Zheng, Huo & Zhang, 2000, syn. nov.; Tetrix rectimargina Zheng & Jiang, 2004, syn. nov.; Tetrix ruyuanensis Liang, 1998, syn. nov.; Tetrix xianensis Zheng, 1996, syn. nov.; Tetrix xinchengensis Deng, Zheng & Wei, 2007, syn. nov.; Tetrix yunlongensis Zheng & Mao, 2002, syn. nov.; Tetrix zhoushanensis Gao, Liu & Yin, 2022, syn. nov. It is expected that there will be the discoveries of more synonyms of this and other Tetriginae species from the Eastern Palearctic.
