Abstract Genetic sexing strains (GSS) are important tools for the sterile insect technique (SIT), an environmentally friendly and species‐specific insect pest control method. GSS feature sex‐specific phenotypes, enabling sex sorting in mass‐rearing facilities and male‐only releases, which significantly improve the cost‐effectiveness and efficiency of SIT programs. In classical GSS, sex linkage of marker gene(s), such as white pupae ( wp ), is achieved through an irradiation‐induced translocation between the marker‐carrying autosome and the Y chromosome. However, this approach may render GSS males semisterile. The recently proposed neo‐classical GSS concept suggests using genome editing to achieve sex linkage by directly inserting the wild‐type marker allele onto the Y chromosome, potentially yielding GSS males with higher fertility. In this study, we examined the Ceratitis capitata wp gene as a genetic marker for the neo‐classical GSS concept and developed a minimal, intronless version of this gene, termed mini‐ wp . We demonstrate that a single copy of mini‐ wp is sufficient to restore the wild‐type brown puparium phenotype and is functional when integrated at various positions within the C. capitata genome, including the X chromosome. Due to its smaller size (4689 bp, including 2000 bp of putative promoter region) relative to the full wild‐type wp allele (20868 bp), mini‐ wp may facilitate its precise insertion into the Y chromosome, representing an important step toward realizing neo‐classical GSS. Furthermore, the methodology developed for designing and testing mini‐ wp in medfly may be adapted to other Tephritid species with an identified wp gene.