The present study was carried out in Grain Research, Training and Storage Management Cell of the Department of Agri. Entomology, University of Agriculture Faisalabad. The effect of essential oils of three plants Melia azadarach (Bakain), Azadirachta indica (Neem) and Datura stramonium (Datura) and phosphine fumigation alone and in combination were evaluated for their repellent and mortality effect against Tribolium castaneum, Rhyzopertha dominica and Trogoderma granarium at various concentrations viz., 5 %, 10 % and 15 % for plant oils, while 100 ppm, 200 ppm and 300 ppm for phosphine fumigation. The effect of these plant oils and phosphine fumigation was also studied on F1 progeny of the test insects. The results showed that maximum repellency of Tribolium castaneum was observed Azadirachta indica which was 77.66 % and Trogoderma granarium which was 76.43% with Datura stramonium. In case of Rhyzopertha dominica it was 81.48 % with Azadirachta indica. For mortality assay, data was collected after 24 h, 48h and 72 h against plant oils. The results revealed that maximum mortality of Tribolium castaneum was observed in Datura stramonium which was 28.82 %. While in case of Rhyzopertha dominica observed maximum mortality was 25.45 % against Azadirachta indica. In case of Trogoderma granarium maximum mortality was observed at Datura stramonium which was 24.30 %. For combination of plant oils and phosphine concentrations data was taken after 24 h, 48 h and 72 h. Maximum mortality of Tribolium castaneum was observed at Azadirachta indica which was 90.55 % at a combination of 15 % concentration of plant oil and 300 ppm phosphine gas while of Trogoderma granarium it was 86.43 % at Melia azadarach at a combination of 15 % of plant oil and 300 ppm of phosphine gas . In case of Rhyzopertha dominica observed mortality was 93.22 % at Azadirachta indica at a combination of 15 % of plant oil and 300 ppm phosphine gas. Mortality of insects against phosphine gas was also observed. Data showed that maximum mortality of Tribolium castaneum was observed at 300 ppm of phosphine gas which was55.93 % and in Trogoderma granarium it was 46.33 % at 300 ppm gas concentration. While in case of Rhyzopertha dominica it was 64.41 % at 300 ppm phosphine gas concentration. After that from the survivors of test insects F1 progeny data was recorded after thirty days of releasing in fresh grains at 30 + 2̊C and 70 + 5 % R.H. results showed that maximum F1 progeny of each insect in the following form. i.e. 0 % > 5 % > 10n % > 15 % >. Where 0 % is control. Minimum F1 progeny was observed at 15 % concentration of plant oils. In case of combination of plant oil and Phosphine gas concentration trend was like this. 0 % > 5 % + 100 ppm > 10 % + 200 ppm > 15 % + 300 ppm. So minimum F1 progeny was observed at 15 % + 300 ppm gas combination in all test insects. While in case of alone phosphine gas concentration maximum F1 progeny was observed at 100 ppm concentration. Minimum F1 progeny was observed at 300 ppm.