Trichogramma japonicum Ashmead (Hymenoptera: Trichogrammatidae) and Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) are important parasitoids of Lepidopteran pests and are used for biological control in rice fields. In this study, the response of two of these parasitoids to four insecticides (chlorpyrifos, chlorantraniliprole, emamectin benzoate, and spinosad) were evaluated at target sublethal concentrations (TSC₁₀ and TSC₂₅, representing the LC₁₀ and LC₂₅ to the target pest) of the important rice pest, Cnaphalocrocis medinalis (Guenée). Each of the insecticides led to the mortality of adult T. japonicum and T. dendrolimi at TSC₁₀ and TSC₂₅, whereas no significant differences in the mortality of T. japonicum between TSC₁₀ of chlorantraniliprole and control groups occurred. The parasitic capacity increased at F₀ of T. japonicum at the two TSCs of spinosad treated host eggs, whereas the TSC₁₀ was lower for emamectin benzoate at F₁ for T. japonicum. The TSCs of chlorpyrifos treated host eggs negatively influenced the emergence rates of T. japonicum at F₁. Emamectin benzoate with TSC₁₀ reduced the female ratio of T. japonicum at F₁. For T. dendrolimi, the TSCs of chlorpyrifos treated host eggs negatively influenced the emergence rates at F₁. These findings indicate that T. japonicum and T. dendrolimi are affected by insecticides at TSCs, and among the four insecticides, chlorantraniliprole had the lowest mortality rates for T. japonicum and T. dendrolimi at TSCs.