A laboratory experiment was designed to evaluate different incubation periods for the development of Bactrocera zonata. Larvae of the same instar were subjected to cold incubation periods for 1-15 days as treatments at 5 ± 1 °C and 50% R.H. The periods to complete their life cycle after cold treatments were counted to detect the coldest period affecting the survival of B. zonata. Results revealed that, compared to the control which completed their life cycle normally, all treatment periods did not affect the life cycle of the cold-treated insects except those of the 9^th-day treatment which produced about half of the population, while the treatments from 13^th-15^th days resulted in the survival of the highest population of insects completing their life cycle. Also, it was noticed that, the preassociativity of B. zonzta in the orchards during January month at Fayioum through hanged both of pheromone and nutritive traps.