Abstract: In the field, the uniform design was used to test the index of Interference of Population Control (IIPC) of alcohol extract of Artocarpus heteropyhllus against the natural population of diamondback moth Plutella xylostella (L.) by different concentrations and span of times. Through assaying and returning of quadratic equation, a model depicting the correlation between IIPC and two factors (A and B) using uniform design was shown. The model equation is Y=0.4628-10.6164A-0.0212B+117.1290A2-0.7762AB(Y-IIPC, A-concentration, B-times). Actually, This model equation be used to check IIPC under the nature condition, the result showed that the composing of 0.05 g·mL^-1×3 times gave the best effect of influencing, IIPC was 0.0448, followed by the composing of 0.04 g·mL^-1×3 times, IIPC was 0.0688. The alcohol extracts of Artocarpus. heterophyllus was isolated by immersing five kind organic solvates, and that corresponding extracts have separated out. The extracts of first isolating were surveyed about the bioassay. The result showed that ethyl acetate extract of the alcohol extracts of A. heterophyllus had marked effect of oviposition deterrent and antifeedant on diamondback moth, and their rate was 59.16% and 57.34%. Twenty fractions were obtained using silica gel column from the ethyl acetate extract of the alcohol extracts of A. heterophyllus. By the bioassay, the fractions of L1 and L13 and L18 and L19 showed strong effect of antifeeding, their rate of antifeeding was 85.71%, 73.33%, 78.57%, 88.87%, respectively.

Key words: Artocarpus heteropyhllus, Alcohol extract, Brassica parachinensis, Plutella xylostella (diamondback moth), Population Control, Life table, Analyzing of active chemical composition