title: Chromosome studies on primitive chrysomelids. 1. A survey of six species of Criocerinae (Coleoptera, Chrysomelidae).
abstract: The chromosome numbers and sex-determining systems of six species of Criocerinae have been determined, four of them for the first time. Oulema melanopus L., Crioceris paracenthesis L., C. asparagi and C. duodecimpunctata L. share a 7II + Xyp formula, while Lema puncticollis Curt. has 8II + Xyp and Lilioceris lilii shows a karyotype of 2n = 20 chromosomes. The modal chromosome formula and possibly the most primitive one for Criocerinae is 7II + Xyp, but it should not be assumed as the ancestral formula for the Chrysomelidae since the most ancient groups of chrysomelids have been little investigated. The karyological interspecific comparisons of some species of Criocerinae seem to indicate a trend towards more symmetrical complements by both increases and decreases from the modal chromosome number.
mesh_terms: D000818:Animals; D002875:Chromosomes / Q000648:ultrastructure*; D001517:Coleoptera / Q000145:classification / Q000235:genetics* / Q000648:ultrastructure; D007621:Karyotyping