Sexual reproduction is the dominant mode of reproduction in plants and animals; however, some species from various taxonomic groups reproduce asexually. Because some of these asexual species lack DNA recombination and so have low genetic variability, these asexual species are more likely to go extinct than sexual species. Neochrysocharis formosa (Westwood) (Hymenoptera: Eulophidae) is a solitary endoparasitoid in which both arrhenotokous and thelytokous strains occur in sympatry. The thelytokous strain is infected by a parthenogenesis-inducing Rickettsia bacterium. We investigated whether fertilized progeny can be produced between females and antibiotic-induced males of the thelytokous strain. The males produced by antibiotic treatment showed the same courtship behaviors as the arrhenotokous males, but at a lower rate, and did not produce fertilized progeny. The results confirm that the thelytokous strain has been maintained by a functional apomixis mechanism rather than by occasional sex, preserving a degree of heterozygosity.