Parasitoid hymenoptera are characterized by a haplo-diploide reproduction:fertilized eggs give diploid female whereas unfertilized eggs produce haploid males. Moreover, females are able to control sex allocation by controlling the fertilization of the eggs during the oviposition by the mean of spermatheca aperture control. Regarding environment conditions, host quality or superparasitism level, females may adapt the sex-ratio of the offspring. Sex determination is also linked to other factors. Indeed, diploid individual with a male phenotype were found by several researchers. Different hypothesis may explain that phenomenom: genetic balance, (2) single locus sex determination, (3) multilocus sex determination, (4) presence of Wolbachia. Our objectives is to analyse these different hypothesis using micro-satellites and flow cytometry