1999 年 64 巻 4 号 p. 367-369
An analysis was made of C-banded karyotype of Acanthoscelides obtectus (Say) from Slovakia (Central Europe). The results indicate that the chromosome number is 2n=20 (the ancestral number for bruchid beetles). The males possess XY type of the sex-chromosome mechanism. The sex-chromosome mechanism in the females is, however, XX type. 5 pairs of autosomes are metacentric, 3 pairs are submetacentric and 1 pair is subtelocentric. The X chromosome is submetacentric and the Y subtelocentric. The sex chromosomes are the smallest elements of the set. The examined karyotype shows only pericentromeric position of constitutive heterochromatin in all autosomes and the sex chromosomes X and Y.