The effect of cold plasma generated from corona discharge on different stages of Sitophilus granaries (L.), Rhyzopertha dominica (F.) and Tribolium castaneum (Herbst.) were investigated, insect species stages exposed to three voltage levels (150, 200 and 250V) of the cold plasma for nine exposure times between (1-25 minutes). Results showed that, adult stage of each insect species was most sensitive to cold plasma while, the pupal stage of each insect was the most tolerant one. Also, S. granarius were the most sensitive to cold plasma followed by R. Dominica and T. castaneum was the most tolerant insect, a complete kill of S. granaries adults was obtained after 10min only at 250V but eggs and larvae need 15min of exposure. Only 67.3% of Pupa was killed after the longest exposure period (25min). Meanwhile, cold plasma at 250V and 25min of exposure was sufficient to kill adults and larvae of R. Dominica completely.While, the lowest effect of cold plasma was achieved against T. castaneumstages, the highest voltage (250V) and 25min of exposure gave 80.0, 78.5, 79.2 and 50.6%mortality of adults, eggs, larvae and pupae, resp. Also, a significant enhancement in germination indices of wheat seeds was achieved after exposing to cold plasma.