Effect of nutritional balance, different yeast derivatives and wheat germ in the adult diet of Ceratitis capitata (Wiedemann) on survival and fecundity

GOANE, L.; CONTI, C.; GÓMEZ CONTRERAS, L.; VERA, M.T.

Bogotá

Congreso; Congreso Americano de Moscas de la Fruta; 2020

Instituto Colombiano de Agricultura

Adult diet represents a key factor in medfly mass-rearing given the high cost of yeast hydrolysate and several yeast derivatives of lower cost can be used as alternatives to the conventional yeast hydrolysate. Wheat germ, a complete nutrient ingredient, is used in many insect diets and has been shown to favor reproduction when offered in the adult diet of some fruit fly species, representing therefore another option. In addition, many fruit fly species have the ability to achieve optimal levels of nutrients by ingesting complementary foods; concept known as nutritional balance. By doing this, they also avoid possible toxic effects due to overdoses of certain nutrients. In the search to optimize C. capitata mass-rearing, the objective of this work was to evaluate the impact of different yeast derivatives, the addition of wheat germ and the possibility of feeding from two complementary foods on the survival and reproductive capacity of this species. To test so, two experiments were run. In the first, a yeast extract (Bionis®, Brazil) and an enzymatic hydrolysate from brewer's yeast (Palumbo, Argentina) were compared to the most frequently used yeast hydrolysate (MP®, USA). Diets contained three parts of sugar and one part of any of the yeast derivatives. Also, flies were offered either one of the three diets alone or with an additional source of sugar. In the second experiment, the three yeast derivatives were offered with sugar (1:3 ratio) or with sugar and wheat germ (1:3:1 ratio). Egg production and daily mortality were recorded in cages with 25 couples. GLM were built to analyze egg production and Kaplan-Meier test to compare survival among treatments. Egg production of C. capitata females was similar regardless of the yeast derivative used in the adult diet and was not improved either with the addition of wheat germ or with the opportunity to perform nutritional balance. Survival was improved in some cases. Results allow us to conclude that cheaper diets can be attained by replacing yeast hydrolysate by other cheaper yeast derivatives rather than with the addition of wheat germ. Large-scale evaluations should be undertaken in order to validate our laboratory results.