I study evolutionary developmental genetics of sex determination in insects of economic relevance, such as Ceratitis capitata, Bactrocera oleae and B. dorsalis. I have contributed to the development of the first gene transfer in a non-Drosophilidae species, C. capitata potentially useful also for future applications. We have discovered that the master female-determining gene of C. capitata, transformer (Cctra), can autoregulate differently from the D. melanogaster orthologue, which lost this function. Other research groups have found that Cctra autoregulating orthologues are widely conserved in dipteran, hymenopteran, coleopteran and hemipteran species. We have also recently identified the master male-determining gene of C. capitata, the Maleness-on-the-Y (MoY), which is conserved only in some Tephritidae species. We have successfully applied RNAi and CRISPR/Cas9 methods in the three species of our interest causing sex reversal when targeting Cctra or MoY genes.