Chromosomal analysis of Trabala vishnu Lef. (Lasiocampidae, Lepidoptera) with clear indications of localized centromeres.

Mitotic and meiotic chromosomes of Trabala vishnu Lef. (Lasiocampidae, Lepidoptera) were studied after treatment with different concentrations of colchicine. Although with milder concentrations of the drug the chromosomes bore typical spherical dot-like or elongated forms, the clear monocentric nature of the chromosomes was revealed at the mitotic metaphase, and metaphase II by the use of stronger concentrations of the drug. It was possible to make karyograms of the mitotic and metaphase II chromosomes on the basis of the centromeric position. The fifty-two elements were grouped into six pairs of metacentric, seven pairs of sub-metacentric, eleven pairs of acrocentric, and two pairs of microchromosomes. Diakinetic figures in the colchicinized insects showed discrete chiasmata in the bivalents.