Translocations and mutations: Tools for medfly control in Argentina

The research objectives during the past five years involved a series of basic and applied studies for the genetic control of the Mediterranean fruit fly. Four new mutations were isolated, described and mapped. A set of three translocation strains was assembled as a tool to facilitate chromosome localization of these or any other new mutations. The stability of the pupal sexing strains T(Y;5)122 and T(Y;3;5) 11 was studied under simulated mass rearing conditions. Two per cent of recombinant females were generated from brown pupae, in generations 17 and 15, respectively. Using wild type strains of different geographical origins, significant heterosis in F1 and F2 was detected for body weight, pupal survival, longevity and fecundity. A method is proposed to 'exploit' heterosis for genetic sexing. White-eye mutant males were unable to reach trimedlure traps in open areas; they were poor fliers and exhibited poor mating performance in field cages. Ale mutant behaviour augurs well for the future development of a 'genetically impaired female' technique for medfly control. (author)