The insecticidal action of two insect growth disruptors (IGDs): the chitin synthesis inhibitor, diflubenzuron, and the ecdysone agonist, chromafenozide, were evaluated against the house fly, Musca domestica, larvae. The LC₂₅, LC₅₀, and LC₇₅ were used for each IGD. The total carbohydrate, protein and lipid contents were estimated, and the effects of these compounds on native protein, glycoprotein and lipoprotein patterns were investigated in third instar larvae (treated as second instars). Results of susceptibility tests demonstrated that chromafenozide is more toxic to the larvae than diflubenzuron. Application of the three lethal concentrations of diflubenzuron and chromafenozide to second instar larvae increased the total protein, carbohydrate and lipid contents in treated third instar larvae as compared to the control. The electrophoretic study revealed a reduction in native protein bands, as well as the appearance of new lipoprotein and glycoprotein bands in treated larvae. Results showed that both diflubenzuron and chromafenozide cause physiological disorders, biochemical changes as well as death of treated M. domestica larvae.