Biologists at Rochester University in the USA have made known the discovery of the unfertilized eggs of tricograms, small parasitic hymenopterans, which must be males by themselves, become female embryos while mothers do not eat honey or grow at temperatures above 30 C. Honey contains antibiotics that kill bacteria. Therefore, females can reproduce without males.
Other researchers from the same university have made surprising discoveries. In a generation of two species of crossed wasps, only males appear. So it is impossible for them to fertilize. Antibiotics also have the most important role in this issue.