JUAREZ Maria Laura
congresos y reuniones científicas
Yeast derivatives and wheat germ modulates fecundity and nutrient content in the South American fruit fly
Congreso; 10th International Symposium on Fruit Flies of Economic Importance; 2018
Background: Anastrepha fraterculus (Wiedemann) is a pest of great economic importance in South America for which the Sterile Insect Technique is promoted. Because oogenesis takes place during the adult stage, mass rearing facilities should provide females a diet that maximizes egg production at the lowest cost. We investigated the effect of yeast derivatives of different cost and the addition of wheat germ (WG) on fecundity. Additionally, we evaluated different ratios of yeast derivatives or wheat germ on ovary maturation, fecundity and fertility as well as their association with female nutrient content. Methods: Fecundity was assessed on laboratory females provided the corresponding diet from emergence. Five mated females were placed in plastic containers with agar slices as oviposition substrate. Number of eggs laid was scored every 48 h and a sample of eggs placed in a moist chamber to analyze fertility. Ovary maturation was assessed dissecting virgin females daily to estimate the percentage of sexually mature females. Nutrient content was determined for newly-emerged, sexually mature virgin females (10-d-old) and mated females (14-d-old). Results: Females fed hydrolyzed yeast (HY) and yeast extract (YE) attained the highest fecundity levels and those fed brewer's yeast (BY the lowest. The addition of WG in the adult diet improved fecundity. Reducing the amount of HY negatively affected fecundity and ovary maturation. Increasing the amount of BY or WG was not sufficient to improve fecundity. Egg hatch was not affected by the diet. Nutrient content of females varied according to the adult diet, age and mating status. Protein and carbohydrates showed a complementary pattern. Protein decreased when HY decreased in the diet and carbohydrate increased. Lipids showed a substantial drop from emergence.Conclusions: HY can be replaced in the adult diet by other yeast derivatives as YE; and WG emerges as a relevant component of the adult diet. Our results reinforce the relevant role of adult environment for female performance since females were not able to compensate high protein deficiencies in the adult diet from reserves obtained during the larval stage. Females resigned fecundity but not fertility when fed a yeast-reduced diet. Being BY a low cost alternative, further research are needed to promote its adoption in the adult diet. Nutrient optimization could be reached providing adults nutritional complementary sources rather than a single diet. In all, our findings provide novel baseline information to understand the role of nutrition on reproductive performance of A. fraterculus females providing valuable advances in the search of cost-effective adult diets at mass rearing facilities.