Abstract
The chromosomes of a weevil, Catapionus gracilicornis, were investigated based on the materials coming 29 localities covering Hokkaido and northern Japan with special regard to parthenogenesis and polyploidy. Hokkaido specimens were represented by a tetraploid parthenogenetic race. In Akita and Iwata Prefectures, tetraploid and pentaploid parthenogentic races coexisted. Both female and male specimens collected in Kayatsuki, Niigata Prefecture were all diploid bisexual race showing basic numbers, 22 in diploid and 11 in haploid.
