Alternative larval diets for mass rearing of screwworm, Cochliomyia hominivorax

The mass rearing of the screwworm fly, Cochliomyia hominivorax (Diptera: Calliphoridae), for programs that integrate the Sterile Insect Technique in the Americas is part of one of the largest insect mass rearing programs in the world. Most of the cost and labor required in mass rearing systems is related to the larval diet, what enhances the relevance of the constant development of novel diets taking into account their effectiveness, cost and practicability. In this research, two bioassays with alternative diets made using local products were performed in order to evaluate the feasibility and efficiency of these diets for screwworm rearing in Brazil. Two liquid diets (having sugarcane bagasse or coconut fiber as bulking agents), a meat diet, and a gelled diet were tested. The biological parameters evaluated (larval weight, larval viability, pupal weight, adult emergence, and sex ratio) were satisfactory according to mass rearing standards and the diets did not differ statistically (P > 0.05). Due to its higher number of advantages, as high larval viability and lower cost, the gelled diet developed is recommended for screwworm larvae rearing in Brazil.