CHROMOSOME STRUCTURE IN <i>CHILOCORUS</i> (COLEOPTERA: COCCINELLIDAE). I. FLUORESCENT AND GIEMSA BANDING PATTERNS

Abstract

Chromosomes of six species of Chilocorus have been examined for their reaction to Quinacrine (Q), and to Giemsa (G) after a variety of 'Denaturation-Renaturation' schedules and digestion with trypsin. Four types of chromatin can be distinguished with these techniques: 1, moderately stained with both Q and G; 2, brightly stained with Q and darkly stained with G; 3, unstained with Q but darkly stained with G; 4, unstained with Q but moderately stained with G. The last three of these types are restricted in chromosomally monomorphic species to the pericentric heterochromatin, but are variably distributed in the heterochromatic arms of C. stigma. Euchromatin per se does not react differentially. The relationship between karyotype stability and uniformity of banding patterns is discussed.