The sexual maturation and competitiveness of Anastrepha fraterculus males and its manipulation to improve sterile males performance. I. Acquiring basic information about sexual maturation of A. fraterculus males

DIEGO F. SEGURA; SOLANA ABRAHAM; MARÍA T. VERA; JORGE L. CLADERA

La Antigua, Guatemala

Workshop; 1ST Research Coordinated Meeting on Improving Sterile Male Performance in Fruit Fly SIT; 2004

International Atomic Energy Agency

The South American fruit fly, Anastrepha fraterculus, is a major fruit pest. Implementation of the Sterile Insect Technique (SIT), would be desirable to control this species since only insecticides are currently available. Research efforts have been initiated in Argentina regarding mass rearing, sexual competitiveness and survival of sterile males in the field. Results from these studies, and the experience gained in other species, envision a promising future for the development of the SIT against this pest. Better performance of sterile males in the field will probably be gained transferring the experience on acceleration of sexual maturation and enhancement of sexual competitiveness from other species of fruit flies. In A. suspensa and A. ludens, the juvenile hormone (JH) proved to accelerate sexual maturation. Also, sexual competitiveness has been shown to be associated with the posteneral intake of protein, also necessary to achieve sexual maturation. Yet, current knowledge on sexual maturation and competitiveness of A. fraterculus males is still incomplete. The main objective of this work is to improve different aspects of the sexual behaviour of A. fraterculus sterile males accelerating its sexual maturation and enhancing its sexual competitiveness. In a first series of experiments, the process of sexual maturation in males will be studied. One day after emergence, and daily until all the males are sexually mature, sets of males will be observed for “sexually-mature” behaviours. Sexual maturation will be inferred when males start searching for leks, releasing pheromone and trying to copulate. The search for leks will be analysed via olfactotory cues in a Y-tube olfactometer. Pheromone emission will be determined in males placed in mating arenas in lab cages. Ability to copulate will be determined by the acceptance of experimental males by sexually mature virgin females. In a second series of experiments, acceleration of sexual maturation will be studied by supplying JH analogues and different doses of proteins. The mating competitiveness of males receiving each treatment will also be analysed. Finally, those treatments that successfully enhance sexual competitiveness and accelerate sexual maturation will be applied to sterile males in outdoor field cages.