Effect of wheat germ in the larval diet of Ceratitis capitata (Wiedemann) on larval development and adult performance

ORDEN SURIANI, F.; CARRASCO, N.; MEDINA PEREYRA, P.; VERA, M.T.; GOANE, L.

Bogotá

Congreso; Congreso Americano de Moscas de la Fruta; 2020

The development of a successful larval diet should consider the appropriate proportion of key nutrients. Wheat germ, a source rich in amino acids, vitamins and fatty acids, is used as an essential ingredient to rear several species of fruit flies as it was proven beneficial for development and reproduction. The objective of this work was to analyze the effect of adding raw wheat germ in the larval diet on rearing parameters of C. capitata. We predict that larvae raised in diets without wheat germ or with a small amount of wheat germ will accumulate less lipids and therefore the weight of the pupa and its nutritional status and starvation resistance at the time of emergence will be lower. Laboratory flies were reared in one of 4 artificial diets that contained different amounts of wheat germ along with sugar and brewer's yeast in the following proportions: 101 (not wheat germ), 111 (sugar, wheat germ and brewer´s yeast at the same proportions), 121 (two times wheat germ than sugar and brewer´s yeast), 212 (two times sugar and brewer´s yeast than wheat germ). The experimental unit consisted of a container with 20 ml of diet and 100 eggs. The experiment was repeated twice and in each replicate 7 repetitions per diet were evaluated. Pupal recovery and weight were recorded. Nutrient content were analyzed with biochemical methods and starvation resistance was recorded on newly-emerged flies provided with water but no food. Data were analyzed using LM or GLM according to the variable. The presence of wheat germ affected pupal recovery. Diet 121 rendered less pupae than the other diets. The weight of the pupa was also affected by the type of diet but the results were not consistent between the two replicas. In the first, pupae developed in diet 101 were heavier than those developed in the other diets while in the second, the heaviest pupae were those developed in diet 121. Lipids and carbohydrates contents were similar for all diets analyzed. The highest protein content was recorded in individuals lacking wheat germ in the larval diet. Fast resistance of newly-emerged adults was equal irrespective of the diet in which the larvae developed and the sex of the fly. Results suggest that the addition of raw wheat germ did not improve larval development and adult performance of C. capitata. This could be related to its high capacity to adapt to hosts with different nutritional quality.