A cytogenetic analysis in two species of Cassidinae (Coleoptera, Chrysomelidae).

Two species of Cassidinae have been chromosomally analyzed, Cassida humeralis Kraatz, 1874 from France, with 2n = 18, 8 + Xyp meioformula and Anacassis fuscata (Klug, 1829) from Uruguay, with 2n = 30, 14 + Xy meioformula. The karyotype of the former is composed of similar meta/submetacentric autosomes, a small X-chromosome and a tiny y-chromosome, as many other Cassida and tribe Cassidini species, whereas that of the latter has four pairs of acro/telocentric autosomes at least and the remaining meta/submetacentrics including the X-chromosome and a tiny y-chromosome, which points out to its probable apomorphic origin by centric fissions, as found in some other species of the tribe Mesomphaliini.