author(s)
Paramjeet Kaur, Abhay Singh Yadav

abstract
The aim of present study was to describe the karyotype of species belonging to the genus Onthophagus and to compile the conventional cytogenetic data available in the literature for this group. Chromosomalinvestigations on three Onthophagus spp. viz. O. fasciatus (Boucomont, 1914), O. unifasciatus (Schaller, 1783) and O. bifasiatus (Fabricius, 1781) were analysed using conventional staining and C-banding. All the three species possessed 20 chromosomes and a modal polyphagan karyotype with Xyp as the male sex chromosome mechanism. Most of the autosomal chromosomes were metacentric or submetacentric, while X and y showed acrocentric nature. Modal chromosome number of these species showed the conservative nature of the karyotype. C-bands were located predominantly at peri-centric position. Along with this chiasma frequency, terminalisation coefficient and sperm number count were also calculated which again showed a close relationship among these species.