The aim of this study was to determine the effects of zinc (Zn), iron (Fe), nickel (Ni), copper (Cu), and cobalt (Co) in different concentrations on the total consumption amount, pupal weight, pupal protein and lipid content, the development time of the last instar Hyphantria cunea. For this purpose, ten diets were prepared using 4% and 12% concentrations of each metal. A total of 11 diets were made, including one control diet. Chloroform was used to determine the pupal lipid amounts. Protein analysis was performed by semi-micro Kjeldahl method with Kjeltec Auto 1030 analyzer (Tecator, Sweden). ANOVA-Dunnet test was used for statistical analysis. With increasing iron and copper concentrations in the diet, the consumption amounts, pupal weights, pupal protein and pupal lipid amounts of the larvae decreased, while the development time was prolonged. Consumption amounts, pupal weights, pupal protein and pupal lipid amounts of the groups containing nickel and cobalt were found to be higher than the control group. It was determined that with increasing zinc concentration, consumption amounts, pupal weights, and pupal protein amounts of the larvae increased, but pupal lipid amounts decreased. In this study, it has been shown that heavy metals affect the physiological processes of H. cunea larvae.