Karyotypic characterization of three weevil species (Coleoptera: Curculionidae, Brachyderini).

Abstract

Karyotypes of three species, Brachyderes incanus, Brachysomus setiger and Paophilus afflatus, belonging to the tribe Brachyderini, were studied using C-banding technique. The species share the same chromosome number 2n = 22 and meioformula n = 10+Xy(p) at all metaphase 1 plates of spermatid division. Some differences between karyotypes were observed in terms of centromere positions and C-band sizes. Most chromosomes are meta- or submetacentric and form a graded series in respect to length. The chromosomes resemble one another in having a rather small amount of heterochromatin restricted to the pericentromeric region and visible as dark stained blocks mainly during early stages of nuclear division. Only in Brachyderes incanus do larger bands occur at mitotic metaphase and diakinesis. These cytogenetic data are in agreement with karyological findings obtained in other species of Brachyderini so far examined.