The chromosome karyotypes of Chorthippus （Megaulacobothrus） aethalinus （Zubovsky） and Ch. （M.） chinensis Tarbinsky were compared. Results show that the chromosome numbers of the two species fit 2n （♂） = 17 = 16 ＋ XO, in which three pairs of autosomal and sex chromosomes were terminal chromosomes, and the other five pairs of autosomes were metacentric chromosomes. These are diagnosis characters for Chorthippus. However, these two species can be distinguished by the different chromosome formula （CF） and the relative length （RL）. The CF in Ch. （M.） aethalinus is K （2n, ♂） = 6m ＋ 11t = 6L ＋ 6M ＋ 4S ＋ XO, whereas that of Ch. （M.） chinensis is K （2n, ♂） = 6m ＋ 11t = 6L ＋ 8M ＋ 2S ＋ XO. In addition, we also found that the relative lengths of sex chromosomes in the two species were different from each other. The sex-chromosome of Ch. （M.） aethalinus is located at the fifth position and its relative length is 8.33% whereas that of Ch. （M.） chinensis is at the eighth position and its relative length is 5.53%. These results show that significantly different genetic features exist for the two species of Chorthippus.
The chromosome karyotypes of Chorthippus albomarginatus （De Geer） which represents the genus Chorthippus Fieber and Euchorthippus unicolor （Ikonnikov） which represents the genus Euchorthippus Tarbinsky were compared. The chromosome numbers for these two species fit 2n （♂） = 17 = 16 ＋ XO, in which five pairs of autosomal and sex chromosomes are terminal chromosomes, and the other three pairs of autosomes are metacentric chromosomes. This similarity between the two genera indicates that they have a close phylogenetic relationship. However, these two species can be distinguished by their different chromosome formula （CF） and the relative sex chromosome length （RL）. The CF in C. albomarginatus is K （2n,♂） = 6m ＋ 11t = 8L ＋ 4M ＋ 4S ＋ XO, whereas that ofE. unicolor is K （2n, ♂） = 6m ＋ 11t = 8L ＋ 6M ＋ 2S ＋ XO. The relative lengths of sex chromosomes in the two species are different. The sex-chromosome of C. albomarginatus is located at the ninth position and its relative length is 2.96% whereas that ofE. unicolor is at the eighth position and its relative length is 4.26%. These results show that significantly different genetic features exist for the two genera.
