Abstract: The lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) very harmful insect pests to cereals grain including wheat. Imidacloprid among the natural insecticide, so it tested against the target pests under laboratory and store conditions. Results showed that, the LC50 of Imidacloprid and nano imidclorprid recoded 80 and 32 conidia/ml. Also, results showed that the accumulative mortality percentage was gradually increased after increasing the period of exposure to foam treated with the two pathogens tested. Nano-Imidacloprid showed a highest accumulative mortality (89.5%), followed by Imidacloprid (50.1%).The reduction of the eggs laid per female was scored 90.3% eggs/female after treatments with nano Imidacloprid. Under store conditions the percentage of infestations was significantly decreased to 8% and 19% after treating the stocks sacs with nano-Imidacloprid and Imidacloprid, respectively, as compared to 99% in the stock sacs control (untreated).