Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Cytogenetic characterization of the genome of mealybug Planococcus citri (Homoptera, Coccoidea).

Abstract

In Planococcus citri (2n = 10) male and female individuals are both diploid, however in males, at the stage of blastula, the haploid chromosome set of paternal origin becomes heterochromatic, even though its complete inertia has been considered questionable. Data are presented on the cytogenetic characterization of the chromosomes of P. citri and information is given on (i) the fluorescence karyotype (D287/170), which to the authors knowledge is the first banded karyotype of a mealybug to be described; (ii) the chromosome localization of constitutive heterochromatin; (iii) the chromosome localization of ribosomal DNA sites; and (iv) NORs activity. The data also show, for the first time, that in the heterochromatic chromosome set ribosomal genes are still active.