Abstract: The population dynamics of Asian corn borer(ACB) Ostrinia furnicalis and the yield loss caused by it were studied in Wuchang in 1985-1989. Ageneral model for its multivariate dynamic economic threshold is established as ETi(t)= Ki(P₁,P₂，…，P_n)/[1+exp(a-b×t)]^2×[1+exp(a-b×X)] ×exp(a-b×t) Where Xis the interval from emergence of first eggmass to sampling date, t denotes time, and a and b are Logistic parameters which are varied with defferent ACBgenerations. The value of Ki(p₁,p₂,...,p_n) is determined by state i, which is described with a property serial value Pj(j=1,2,...,n) named state index. The model is programmed through IBM PC/ATmicrocomputer and validated in corn production.

Key words: Asian corn borer, Simulation model, Multivariate dynamic economic threshold