Karyotypes of Monochamus alternatus and Anoplophora glabripennis.

Abstract：The karyotypes of Monochamus alternatus Hope and Anoplophora glabripennis Motschulsky were studied. According to the optimum conditions and the best material for each species of long-horn beetle，we made and examined the slide specimens of chromosomes. The best material for M. alternatus was testis or ovary of 7 d pupae. The chromosomal number was 2n = 20. The sex-determining mechanism was Xyp . The chromosome was composed of 5 pairs of large autosomes，4 pairs of middle autosomes and 1 pair of sexchromosomes. The sex-chromosomes were middle-sized and situated in the last among all chromosomes. The genome-style was 5 L + 4 M + Xyp . The best material for A. glabripennis was testis or ovary in the newly emerged adults，and its chromosomal number was 2n = 20. The sex-determining mechanism was Xyp . The chromosome was composed of 6 pairs of large autosomes，3 pairs of middle autosomes and 1 pair of sexchromosomes. The sex-chromosomes were middle-sized and situated in the last among all chromosomes. The genome-style was 6L + 3 M + Xyp .