Cytogenetic investigations on seven Palaearctic weevil species (Coleoptera, Curculionidae).

Cytogenetic investigations were carried out on seven species of bisexual weevils from five subfamilies. The following numbers of chromosomes were found in individual species: 2n = 22, n male = 10 + Xyp in Ptochus porcellus Boh. (Otiorhynchinae); 2n = 40, n male = 19 + Xyp in Larinodontes turbinatus Gyll. (Cleoninae); 2n = 26, n male = 12 + Xyp in Curculio pellitus (Boh.) (Curculioninae); 2n = 30, n male = 14 + Xyp in Acalles camelus (F.), Acalles echinatus (Germ.), Acalles hypocrita Boh. (Cryptorhynchinae), and 2n = 40, n male = 19 + Xyp in Cionus hortulanus (Foucr.) (Mecininae). The heterochromosomes of all the examined species form, in the first meiotic metaphase, a parachute bivalent. The chromosome number and sex determining system of six species and two genera are described for the first time.