| reproductive isolation between 2 karyotypes in natural populations of the leaf beetle chrysolina aurichalcea. | japanese populations of the leaf beetle, chrysolina aurichalcea, have 2 main karyotypes, type 31 and type 41, which greatly differ in chromosome number and form. we examined their geographical distribution and reproductive isolation in southern hokkaido, northern japan. type 41 was widely distributed in the survey area, whereas type 31 was restricted to a narrow portion. a transect across each karyotypic habitat revealed that both karyotypes co-occurred in a approximately 5 km wide zone, with fe ... | 2010 | 20015967 |