The genetic possibility of putative intergeneric hybridization between two sympatric Namib tenebrionids is descriptionbed. Crosses and reverse crosses were carried out between the putative parent species, as well as between two other related taxa. Egg production and hatching success were recorded for intergenericalIy, intersubspecifically and intraspecifically mated females as well as for females that were isolated from males and these data were compared. Obvious differences in the morphology of hybrid and nonhybrid larvae are descriptionbed. Keywords: Beetle populations, Breeding experiments, Egg production, Hybridization, Larvae, Onymacris rugatipennis, Physadesmia globosa, Putative hybrid male, Spermatozoa, Zygote.