Abstract: Based on the growth features of aphid population and mathematical principles,a simulationmodel is deduced as.N(t)=(Sβ3/r)(t-α)^β-1.exp[-(t-α)^β/r].Where:N(t)is the popula-tion density at t time;S is the total number of aphid population;α is the earliest day thepopulation emerges;β is the parameter of curve form,describing curve type;r is the relativegrowth rate.There are two turning points in the curve,showing an interval between prosperity and decline of population.After testing on real data,this extended Weibull model isproved practisible in IPM computers.

Key words: short sunlight, nectarine flower bud, dormancy induction, cytochrome electron transport pathway, alternative respiration pathway