Mass rearing fruit flies of the genus Anastrepha for the sterile insect technique involves the use of artificial larval diets that commonly contain corn cob powder as a bulking agent. Corn cob powder varies in quality, and larval diets that contain it can be reaching at high temperatures (>34°C), which subsequently has a negative effect on pupal weight and adult survival. In addition, corn cob powder is susceptible to contamination by mycotoxins, which can inhibit larval development and cause high larval mortality. The objective of this work was to develop a low-cost artificial larval diet for mass rearing Anastrepha spp. fruit flies using coconut fiber, a nonconventional bulking agent, and to evaluate its effects on the quality parameters for A. ludens wild-type, A. ludensTap-7 GS-strain, A. obliqua, A. serpentina, and A. striata.The coconut fiber diet resulted in an increase in the larval and pupal weight of A. ludens Tap-7 GS-strain and A. obliqua, an increase in the larval weight of A. ludens wild-type, an increase in the flight ability of A. obliqua and A. serpentina and an increase in adult eclosion in A. ludensTap-7 GS-strain. The coconut fiber diet resulted in increased production and quality of the mass-reared flies, reduced the cost of the diet by 15 and 20% for A. ludens and A. obliqua, respectively, and led to further cost savings through reduced labor processes.