Two citrus varieties, Navel orange and Valencia were subjected to be infested by mature flies of Mediterranean fruit fly Ceratitis capitata(Wiedemann) for 24 hours. The infested fruits were exposed to three different cooling temperatures 1,2,and 4°C for 14 days. It was noticed that eggs, first and second larval instars were highly affected  by  cooling  treatments  . A delay of development was noticed in the third larval instar but not death when infested fruits were stored in 4°C and it may need longer exposure period to cause death.