The variations in weight, water content and supercooling point (SCP) were studied in Tineola bisselliella at different stages in its development.The egg, with a fresh weight of 0.037 mg and a water content of 314% of the dry weight, is the stage most resistant to freezing with an SCP of -23°C. The young larva (second instar), with a fresh weight of 2.5 mg and a water content of 145% of the dry weight, is the least resistant stage with an SCP of -13°C. Despite the large differences in weights and water contents between males and females, they have the same SCP value of -19°C.Because of the large individual variations observed in this species, it appears necessary to treat infested materials with a temperature lower than or equal to -29°C to destroy all stages of development promptly.