Abstarct: The role of food in growth, reproduction, fertility has been proven, if insects benefit from desirable food and higher nutritional value, their fertility will be improved. This is one of the important goals of breeding parasitoid intermediate host insects such as Trichogramma bee, which feeds on Mediterranean moth larvae as a laboratory host. The aim of the present study was to investigate the effect of adding letose and sucrose ma sugars to the diet of Mediterranean moth on the biological characteristics and nutritional indices of Mediterranean moth flour in vitro. Insects were reared in vitro (temperature ± 27 1 1 ° C, relative humidity 40% and dark light period 14:10 hours). Second instar larvae were used in the experiments. Treatments included the first treatment: flour (97 g) +, sucrose sugar (3 g), the second treatment: flour (97 g) + maltose sugar (3 g), the third treatment (control) was flour (100 g). The experiments were performed in a completely randomized design. The effect of adding sugar on the biological characteristics of Mediterranean flour moth in all treatments compared to the control showed a significant effect (P≤0.001), so that the pupal weight was the most affected by sucrose treatment. (1.26 12 0.12 mg / day) The length of the pupal period was significantly reduced under the influence of sucrose and maltose diets. (9.60 2 2.14 days) The highest percentage of healthy butterfly moths leaving the pupal crust was related to sucrose treatment. (81.00 9 9.21%) The length of the larval period of Mediterranean flour moth under the influence of sucrose diet showed a significant decrease. (46.53 3 3.29 days) With the consumption of sucrose in the diet, the lifespan of the adult showed a significant increase (15.20 ± 1.74 days). The highest spawning rate was related to the diet containing sucrose. (442.93 27 27.38 eggs) and egg hatching rate were not significantly different between maltose and sucrose treatments (84.40 59 4.59%) but showed optimal performance compared to the control. The effect of diets on four nutritional indices, relative growth rate (RGR), relative consumption rate (RCR), food efficiency (ECI) and relative digestion index (FDI) was significant in all treatments compared to the control. (P≤0.001). Second-instar larvae of flour moth raised on diets containing sucrose and maltose had the highest converted feed conversion efficiency (ECI) (6.04 52 0.52%) and the highest relative digestion index (FDI) (3.5 ± 1.5), respectively. 34%). In general, among the treatments, the addition of compounds such as maltose sugar and sucrose sugar to the flour substrate can be considered as a suitable option in the flour meal of the Mediterranean overnight diet. Improving the food quality of larvae is effective in digesting food and improving the biological characteristics of the insect, and it can be hoped that the breeding of willow moth will be more powerful as an alternative host to natural enemies such as Trichogramma bees.