Comparative Study on the Karyotype of Two Species of Megaulacobothrus Caud., 1921 (Acridoidea)

The karyotypes of Chorthippus ( Megaulacobothrus ) aethalinus (Zubovsky, 1899) and Chorthippus ( Megaulacobothrus ) chinensis Tarbinsky, 1927 were compared by means of the conventional cytogenetic method. The results showed that chromosome numbers of two species were 2n( ♂ )=17=16+XO, in which three pairs of autosomal and sex chromosomes were terminal chromosomes, and the other fi ve pairs of autosomal ones were metacentric chromosomes, which are the diagnostic characters of Chorthippus . However, these two species could be identifi ed by the different formulae and the relative length of chromosomes. The chromosome formula of Chorthippus (M.) aethalinus is K(2n, ♂ )=6m+11t=6L+6M+4S+XO, whereas that of Chorthippus (M.) chinensis is K(2n, ♂) =6m+11t=6L+8M+2S+XO. In addition, we found that the location and the relative length of sex chromosomes in the two species were different from each other. Sex chromosome of Chorthippus (M.) aethalinus located at fi fth position and its relative length was equal to 8.33%, whereas that of Chorthippus (M.) chinensis was at eighth position and its relative length was equal to 5.53%. These results showed that signifi cant different karyotype features exist in the two compared species of Chorthippus