Abstract Nitric oxide (NO) was a recently discovered fumigant for postharvest pest control. Because NO reacts with oxygen (O2) spontaneously to form nitrogen dioxide (NO2), NO fumigation must be conducted under ultralow oxygen (ULO) atmospheres to preserve NO and nitrogen (N2) has been used to establish ULO atmospheres in NO fumigation studies in the past. However, carbon dioxide (CO2) can also be used to ULO atmospheres and CO2 fumigation was also reported to be effective in controlling certain insect pests and enhancing toxicity of some fumigants. In the present study, NO fumigations under ULO conditions established with N2 and CO2 were compared for effects against granary weevil, Sitophilus granaries, and confused flour beetle, Tribolium confusum. All life stages of the two insects were subjected to 12 h fumigation treatments with 0.5–1.0% NO at 25 °C under ULO established with CO2 (NO–CO2 treatments) and N2 (NO–N2 treatments). The most tolerant life stage for each species in each fumigation treatment was then fumigated with NO for 24 h fumigation at 25 °C to determine an effective treatment. There were no significant differences in mortalities of adults, larvae, and pupae at all NO concentrations between ULO conditions established with CO2 and N2 for either insect. NO–CO2 was, however, significantly less effective than NO–N2 against eggs of both species. Granary weevil pupae and confused flour beetle eggs were the most tolerant stages for each respective species to NO fumigation: >99% mortality of granary weevil pupae and confused flour beetle eggs were, however, achieved in the 24 h fumigation with 2% and 1% NO, respectively. This study showed that CO2 can be used to establish ULO atmospheres for NO fumigation, but did not significantly contribute to insect mortality.

中文翻译：

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氮和二氧化碳气氛下一氧化氮熏蒸防治粮仓象鼻虫（Sitophilus granaries）和粉螟（Tribolium confusum）的效果比较

摘要 一氧化氮 (NO) 是最近发现的一种用于收获后害虫防治的熏蒸剂。由于 NO 与氧气 (O2) 自发反应形成二氧化氮 (NO2)，因此必须在超低氧 (ULO) 气氛下进行 NO 熏蒸以保存 NO 和氮气 (N2) 已用于在 NO 熏蒸研究中建立 ULO 气氛过去的。然而，二氧化碳 (CO2) 也可用于 ULO 大气，据报道，二氧化碳熏蒸可有效控制某些害虫并增强某些熏蒸剂的毒性。在本研究中，比较了在用 N2 和 CO2 建立的 ULO 条件下的 NO 熏蒸对粮仓象鼻虫、Sitophilus 粮仓和混淆面粉甲虫 Tribolium confusum 的影响。这两种昆虫的所有生命阶段都进行了12小时的0.5-1熏蒸处理。0% NO 在 25 °C 下使用 CO2（NO-CO2 处理）和 N2（NO-N2 处理）建立的 ULO。然后在每个熏蒸处理中对每个物种最耐受的生命阶段在 25°C 下用 NO 熏蒸 24 小时以确定有效处理。对于任何一种昆虫，在用 CO2 和 N2 建立的 ULO 条件之间，在所有 NO 浓度下，成虫、幼虫和蛹的死亡率没有显着差异。然而，NO-CO2 对两种物种的卵的作用明显不如 NO-N2。粮仓象鼻虫蛹和糊粉甲虫卵是每个物种对无熏蒸最耐受的阶段：然而，在 24 小时熏蒸中，24 小时熏蒸处理后，粮仓象鼻虫蛹和糊粉甲虫卵的死亡率达到了 99% 以上不，分别。