Effect of post-teneral diets on the performance of sterile Anastrepha ludens and Anastrepha obliqua fruit flies

The effect of post-teneral diets on the mating performance, pheromone production and longevity of sterile Anastrepha ludens and Anastrepha obliqua fruit flies (Diptera: Tephritidae) was investigated. Enriched pre-release diets improved male mating performance. Wild and sterile males fed on mango and orange fruits achieved the greatest copulatory success, followed by those fed on a 3:1 sugar:yeast (SY) diet. Males fed only on a sugar diet achieved the lowest number of matings. The mean numbers of copulas achieved by wild males were significantly higher than those by sterile males fed on a sugar-only diet, while there were no significant differences between wild males and sterile males fed on yeast diets. There was a trend of reduced mean number of copulas as the proportion of yeast was reduced in the diet, but differences were not significant. Pre-release diets had a significant effect on pheromone production. Males fed on a 3:1 SY diet produced the greatest amount of the three main pheromone components in A. ludens males and two major components in A. obliqua males, followed by males fed on fruits or pasteurized fruit juice. Males fed on a sugar only diet produced the lowest amounts. The longevity response to post-teneral diets was complex. The most yeast-rich diet and the poorest diet (sugar only) resulted in the lowest life expectancies. Flies fed on 24:1 SY diets showed the highest life expectancies for both males and females of the two species. Considering the tradeoffs between mating performance and longevity, the 24:1 SY diet would be recommended for programmes integrating the sterile insect technique, but the effects of these diets on field survival and dispersal still need to be investigated.