ABSTRACT
The Mediterranean fruit fly Ceratitis capitata, can be used to illustrate: the experimental approaches used to obtain this knowledge, how genetic sexing strains are constructed, and how genetics and cytogenetics can be applied to identify or solve certain problems associated with the construction or maintenance of these strains. A genetic sexing system as used in the medfly, consists of two principle components: a mutation that can be used as a marker for selection and a Y-autosome translocation linking the wild-type allele of this marker to the male sex. Chromosome rearrangements are usually induced by irradiation, e.g. gamma radiation. The separation of the sexes on the basis of pupal color has several disadvantages. The most important drawback concerns the equipment required for sorting. Cytogenetic analyses should allow for the establishment of the type of sex determination system that exists in the respective species.
