The chromosomes of two native Japanese weevil species, Trachyrinus sp. and Myosides seriehispidus were studied for the first time. Males of both species are unknown. It is shown that the former has exactly 33 chromosomes in oocytes and the latter 30-33 in oogonial metaphases and 33 at first metaphase. Since no reduction occurs both species must be triploid parthenotes.
The Genetics Society of Japan