| During the period of storage, grain could be damaged by insect, mite, and microorganism pests, which could cause huge quality and quantity losses for stored grain. Nowadays, it seemed that the weapons to protect stored grain against insect pest infestation were decreasing, so the new fumigants with safe, environmentally friendly and efficient characteristics were urgently needed. Ethyl formate is a potential fumigant with properties of rapid insect control and being friendly to environment. In this paper, the lethal effects of ethyl formate against eggs, larvae, pupae and adults of Sitophilus oryzae, T. castaneum and other stored-product pests were systematically studied under different temperatures, EtF dosages and treatment times. In addition, the effects of ethyl formate on acetylcholinesterase (AChE) and carboxylesterases (CarE) in S. oryzae were also studied. These experiments aimed to provide data information to apply ethyl formate to control stored grain insect pests in storehouses.1 The fumigation activities of EtF on stored grain insect pests1.1 The fumigation activities of EtF on S. oryzaeBased on increasing resistance of stored grain insect pest to chemicals and decreasing fumigants, the effects of ethyl formate (EtF) on eggs, early larvae, late larvae, pupae and adults of Sitophilus oryzae were systematically studied by the sealed jar fumigation method under different conditions. The corresponding corrected mortalities of 5. oryzae adults were 90.541% and 99.324% with 40 and 45 μL/L EtF dosage and 12 h fumigation under 25°C. Under the conditions of 24 h fumigation with 30 μL/L dosage at 19 °C, 25 °C and 31 °C, the adult corrected mortalities were 83.108%, 62% and 42% , respectively. These results indicated that the EtF killed the adult weevils in a very short time period, and the fumigation efficacy at relatively lower temperature was better than that at relatively higher temperature. Under the conditions of 20, 25 and 30 °C and 24 h fumigation,...
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