Mass Rearing, Quality Parameters, and Bioconversion in Drosophila suzukii (Diptera: Drosophilidae) for Sterile Insect Technique Purposes.

Abstract

The spotted wing drosophila, Drosophila suzukii Matsumura, has emerged as a major invasive insect pest of small and stone fruits in both the Americas and Europe in the last decade. Females oviposit in ripening fruit, and significant economic losses can occur. Control measures are mainly associated with the use of pesticides, but the sterile insect technique (SIT), an ecologically friendly pest-specific method, could be used against this species. The objective of this study was to estimate the mass rearing, quality control parameters, and bioconversion using four artificial larval diets and their economic aspects oriented to the SIT application. Diets were based on the combination of coconut fiber, corncob powder, Brewer's and Torula yeast and were used as oviposition substrate and larval development. We found that a life cycle is completed in 10.19 ± 0.35 d and that adults live an average of 33.67 ± 0.76 d. The highest number of pupae per gram of diet and the maximum bioconversion (6%) were associated with flies developed in the coconut fiber + Brewer's yeast diet. Under our conditions, the establishment of D. suzukii required at least four generations. The use of 30 × 40 × 30 cm Plexiglas cages, each loaded with 5,000 adults and stocked with 500 g of coconut fiber and Brewer's yeast diet distributed in 15 × 5 × 10 cm plastic trays with a diet layer 3-cm thick, allows a minimum production of 84,000 pupae of D. suzukii per day.