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

摘要

The karyotypes of Chorthippus (Megaulacobothrus) aethalinus (Zubovsky, 1899)and Chorthippus (Megaulacobothrus) chinensis Tarbinsky, 1927 were compared bymeans of the conventional cytogenetic method. The results showed that chromosomenumbers of two species were 2n(♂)=17=16+XO, in which three pairs of autosomaland sex chromosomes were terminal chromosomes, and the other fi ve pairs ofautosomal ones were metacentric chromosomes, which are the diagnostic characters ofChorthippus. However, these two species could be identifi ed by the different formulaeand 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 thelocation and the relative length of sex chromosomes in the two species were differentfrom each other. Sex chromosome of Chorthippus (M.) aethalinus located at fi fthposition 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%. Theseresults showed that signifi cant different karyotype features exist in the two comparedspecies of Chorthippus.