Effects of growth factors on Ceratitis capitata (Wiedemann) larval development were investigated using C. capitata #1 diet as a control diet. C. capitata #1 diet is a chemical base diet with only one nonchemical bulking agent, corncob. It contains 10 exogenous vitamins in addition to those trace amounts already present in corncob, and it is capable of supporting normal larval development. Removal of all 10 growth factors from C. capitata #1 diet resulted in a prolonged developmental period, decreased pupal recovery, pupal weight, and adult emergence, but normal flight ability and egg hatch. C. capitata #1 diet lacking exogenous nicotinic acid resulted in complete second-instar mortality. In the absence of exogenous riboflavin, larvae reached the third instar and pupated, but the rate of development was slower. However, the percent pupal recovery was not significantly different. Pupal weight and adult emergence were significantly decreased, whereas flight ability and egg hatch remained within normal ranges. The effects of omitting exogenous pantothenic acid were similar to those for riboflavin compared with the control diet. The omission of other exogenous vitamins, such as thiamine, pyridoxine, biotin, folic acid, ρ-amino benzoic acid, inositol or choline, had no significant effects on the rate of larval development and survival. Exogenous nicotinic acid was determined to be indispensable (requires a minimum of 2 ppm), whereas riboflavin and pantothenic acid appear to be required (at least >2 ppm) for normal growth and development of C. capitata larvae. Addition of exogenous ascorbic acid phosphate or α-tocopherol in C. capitata #1 diet did not improve C. capitata development or growth. Wheat germ is not necessary as a mass rearing diet additive because two of its major nutrients (α-tocopherol and choline) showed no impact.