Mass Rearing of Four Dacus spp. Using Semi-artificial Diets.

Abstract

Standard diets normally used in mass rearing of Dacus dursalis Hendel and Dacus cucurbitae Conquillett contain some substances such. As wheat germ, dehydrated carrot, and butoben which are normally unavailable in the country. Attempts were made on semi-artificial diets in order to excluded those constitutes and enabled to use not only for the two species but also on the rearing of Dacus correctus (Bezzi), and Dacus tau. (Walker). It was found that the corn-banana diet which composed of corn flour, banana, brewer’s yeast, sugar, tissue paper, sodium benzoate, hydro-chloric acid, and water at the rates of 25, 25, 5, 5, 5, 0.1 gm., and 0.2, 75 ml. respectively gave no significant difference in durations of eggs, larvae, pupae, and adults when compared with the standard wheat germ and corn-flour diets in the rearings of D. dorsalis and D. correctus completion of 5 generations. The corn-banana diet gave pupal weights of the two species higher than the corn-flour diet and the highest percentage of egg hatch to D. dorsalis as compares with other two diets. The corn-wax gourd diet which composed of corn flour, wax gourd, brewer’s yeast, sugar, tissue paper, sodium benzoate, hydro-chloric acid, and water at rates of 20, 40, 5, 5, 5, 0.1 gm, and 0.2, 20 ml. respectively gave no significant difference in the durations of eggs, larvae, pupae, and adults when compared with the standard wheat germ, corn-bitter cucumber, and corn-pumpkin diets in the rearings of D. cucurbitae and D. tau after the completion of 5 generations. While there were no different in the percentages of egg hatch of the four diets, the pupal weight was higher in the corn-wax gourd diet as compared to the others. No significant difference of ovipositional rates of the three generations of D. dorsalis and D. zonatus resulted from the rearings of larvae of both species with the corn banana diet. Larvae of D. cucurbitae and D. tau when reared on the corn-wax gourd diet produced adults which gave better oviposition rates in each successive generation.