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期 刊 ：植物保护学报 2006年

关键词：甲酸乙酯；米象；熏蒸活性；储粮害虫；

Keywords:Ethyl formate, Sitophilus oryzae, fumigant activity, stored-product insects,

摘 要 ：针对储粮害虫抗药性日趋严重、粮食熏蒸剂品种越来越少的现状,采用密闭熏蒸法,系统研究甲酸乙酯(EtF)在不同条件下对米象Sitophilus oryzae (L.) 卵、低龄幼虫、高龄幼虫、蛹以及成虫的致死作用。在25 ℃条件下以40和45 μL/L的药剂浓度处理米象成虫12 h,其校正死亡率分别为90.541%和99.324%;以30 μL/L的浓度在19、25和31 ℃下处理24 h,校正死亡率分别为83.108%、62%和42%,表明甲酸乙酯具有良好的速效性,且在相对低温时比在相对高温时熏蒸效果好。在20、25和30 ℃条件下,熏蒸处理米象成虫24 h,其LC₅₀分别为25.094、28.650和30.875 μL/L;处理48 h时则分别为23.101、25.805和27.316 μL/L。30 g/m³的甲酸乙酯熏蒸处理米象卵、低龄幼虫、高龄幼虫和蛹24 h,对应死亡率为96.930%、99.333%、97.768%和93.386%,表明甲酸乙酯对米象低龄幼虫的熏蒸效果最好,蛹和卵对甲酸乙酯具有较高的耐药性。

Abstract:Based 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 with the sealed jar fumigation method under different conditions. The corresponding corrected mortalities of adults were 90.541% and 99.324% with 40 and 45 μL/L EtF dosage and 12 h fumigation under 25 ℃. Under the conditions of 24 h fumigation with 30 μL/L dosage at 19, 25, and 31 ℃, 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, 30 ℃ and 24 h fumigation, the LC₅₀s were 25.094, 28.650 and 30.875 μL/L, respectively, whereas after 48 h fumigation, the corresponding LC₅₀s were 23.101, 25.805 and 27.316 μL/L. Fumigated the immature stages of S.oryzae 24 h with 30 g/m³ dosage EtF, the mortalities of eggs, early larvae, late larvae and pupae of were 96.930%, 99.333%, 97.768% and 93.386%, respectively, which proved that the fumigation activity of EtF against early larvae was the best, and the pupae and eggs possessed a relatively high endurance to EtF.

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