Abstract: Revertible thelytoky was observed for the first time in the mymarid wasp A. atomus. The thelytokous females develop faster than the arrhenotokous one with a shorter adult longevity. The production of males in the thelytokous species of A. atomus was induced by feeding antibiotics and high temperature treatments to their mother and male sexual functioning was determined. Rifampicin fed females produced 100% male offspring in the F2 generation. The males induced by antibiotic treatment produced sperm, successfully mated with the females and produced female offspring.