This paper presents a simpler method for estimating the base temperature of the insect development by using the optimum seeking method. The objective function iswhere ki, =Ni(Ti-T0);n = the number of the temperature treatment;T0 = base temperature;N, = average duration of the ith treatment;T, = environmental temperature of the ith treatment.The point T0 which corresponds to the minimum of the objective function is the expected value of the base temperature. Thus, the corresponding accumulative heat unit K i...