Abstract: Due to the fact that the existing fumigants had the problems of drug resistanct and safety,it is emergent to development a new fumigant with high environmental stability,volatility and insecticidal activity.ESF has the advantages of high environmental stability,high volatility under normal pressure,etc.We selected ESF as fumigant to study its toxicity and efficacy against three Sitophilus zeamais strains from three different provinces in China.Results showed that the the toxicity equations of ESF against the three strains were similar,y=0.257x-1.941,LC₅₀ was close to 7.540 μL/L.The adsorption rate of ESF in a fumigation bottle loaded with 50% wheat was above five times.The Sitophilus zeamais adults on the surface of wheat could be killed completely after fumination with 96 μL/L ESF for 24 hours,but the death rate of Sitophilus zeamais adults 3 cm below the wheat surface was reduced sharply by above 80%.The results indicated that ESF had significant effect in killing exposed insects,but the insecticidal effect was lowered sharply for insects inside grain bulk due to adsorption barrier of grain bulk.ESF is expected to be used in space and device fumigation.