Larval Diets from Different Protein Sources for Mediterranean Fruit Flies (Diptera: Tephritidae)

Abstract

The effects of larval diets with different protein sources were investigated on the development of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). Casein, corn hydrolysate, soy protein, soy hydrolysate, yeast hydrolysate, lactoalbumin, lactoalbumin hydrolysate, and wheat gluten were tested as replacements for torula yeast. Flies raised on soy hydrolysate had the highest pupation (63%), pupal weight (11.2 mg), days to pupation (9.1 days), and least percentage eclosion (92.8%). Larvae failed to pupate when fed the corn hydrolysate diet. Pupal weight increased with protein levels, fitting to the regression model y = 5.5(ln x)0.5; after a rapid increase, pupal weight leveled off with further increases beyond 5% dietary protein. Protein source and protein concentration affected pupal color; anomalous white pupae resulted from larvae reared on diets containing casein, soy protein, and lactoalbumin at a protein concentration of 3.6%. Increasing the dietary levels of casein, soy protein, and lactoalbumin above 3.6% resulted in normal brown pupae.