The present study describes experiments carried out for 2 years at the Bergerac Institute, on flue-cured tobacco treated with methoprene (Kabat) at doses of 5 ppm and 10 ppm. Biological tests were carried out at 8, 12, 18 and 24 months after the treatment confirmed the efficiency of methoprene in the control of the development cycle of cigarette beetle. On the other hand, during the experimental period (2-year storage) a clear effect of leaf position and chemical composition on the number of cigarette beetle and Ephestia, was observed. From a practical point of view, it was also noted that the treated tobacco could be recontamined by cigarette beetle and Ephestia from untreated sources. As a consequence, it appeared indispensable that treated tobacco should be wrapped to exclude penetration by insects.