The sexual maturation and competitiveness of Anastrepha fraterculus males and its manipulation to improve sterile males performance.

SEGURA, D. F.; ABRAHAM, S.; VERA, M. T.; CLADERA, J. L.

Antigua

Workshop; 1ST RCM on Improving Sterile Male Performance in Fruit Fly SIT,; 2004

IAEA

The South American fruit fly, Anastrepha fraterculus, is a major fruit pest. Since only insecticides are currently used to control it, the implementation of the Sterile Insect Technique (SIT), would be desirable. Research efforts have been initiated in Argentina regarding mass rearing, sexual competitiveness and survival of sterile males in the field. Results from these studies, plus the experience gained in other species from the genus envisions a promising future for the development of the SIT against this species. Better performance of sterile males in the field, with faster sexual maturation and optimisation of its sexual competitiveness, will probably be gained transferring the experience from other species to A. fraterculus. In A. suspensa and A. ludens, the juvenile hormone (JH) has proved to accelerate sexual maturation. Sexual competitiveness has been shown to be associated with the posteneral intake of proteins, which are also necessary to achieve sexual maturation. Yet, current knowledge on sexual maturation and competitiveness A. fraterculus males is still incomplete. The main objective of this work is to analyse different aspects of the sexual behaviour of Anastrepha fraterculus sterile males in order to accelerate its sexual maturation and enhance its sexual competitiveness. As a first step, the determination of the process and enhancers of sexual maturation will be studied. Sexual maturation will be assumed when males start searching for leks, releasing pheromone and trying to copulate. Rearing conditions will be controlled to guarantee that flies from different cohorts are as similar as possible. One day after emergence, and daily until all the males are mature, sets of males will be observed for "sexually-mature" behaviours. The search of leks via olfactory clues will be analysed in a Y-tube olfactometer. Pheromone emission will be determined in sets of 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. With the values to be obtained, it will be possible to start manipulating sexual maturation by supplying JH analogues and different doses of proteins to the recently emerged adults. Treatments that produced good performances in the laboratory will be evaluated outdoors in field cages.