Effect of sweet potato powder content in larval artificial diets on the yield and quality of mass-reared West Indian sweet potato weevil, euscepes postfasciatus(Coleoptera: Curculionidae)

Abstract

To improve the larval artificial diet in a mass-rearing system of Euscepes postfasciatus(Fairmaire), we compared the yield and quality of weevils reared on artificial diets containing different types and amounts of commercial sweet potato powder, using their current diet as the control(made from peeled tubers). We compared a diet containing the same amount of an alternative sweet potato powder(made from the peel of tubers), a diet containing half the amount of the alternative sweet potato powder, and a diet containing no sweet potato powder. The resulting numbers of emerged adults, mean male mass, and rate of sexually matured females did not differ significantly between the diets. Moreover, the mass of females reared on a diet with half the amount of alternative sweet potato powder showed no significant difference from those reared on the control. However, the males reared on the control transferred significantly less sperm than those reared on the other diets. These results indicated that the diet with half the amount of alternative sweet potato powder was superior in terms of yield, quality, and production cost in the weevil mass-rearing system.