Abstract: The 4th and 8th generation life tables were applied to evaluate the effectiveness of natural enemies on common cutworm (Spodoptera litura) population by exclusion index of population control (EIPC). The results showed that the predatory natural enemies of the 1st, 2nd and 3rd instar larvae were the important factor influencing the population dynamics of common cutworm. The EIPCvalues of the 4th and 8th generation common cutworm were 13.904 and 12.496 respectively, which means that the next generation of common cutworm population would increase 15.1206 and 74.678 times of current generation if the predators were excluded. The pathogenic microbes were another important factor affecting the 4th generation population, and its EIPCwas 2.4726.

Key words: Spodoptera litura, Effectiveness of natural enemies, Population control index