氮气对储烟害虫烟草甲的防治效果

为明确实验室及实仓条件下，氮气对储烟害虫烟草甲4种虫态（幼虫、蛹、成虫、卵）的防治效果，在实验室设置20、25、30℃三个温度，以95%和99%浓度的氮气处理4种虫态的烟草甲，分别在1、2、4、6、8、10、12、14 d后取出，记录试虫死亡情况；在烟仓自然条件下，以99%浓度的氮气处理密闭烟垛中的烟草甲，分别在第9天和第30天取出，记录试虫死亡情况。结果表明，实验室条件下，6个组合处理对各虫态烟草甲均有一定的致死作用，且致死效果随氮气浓度的升高、温度的升高和处理时间的延长而增强。同时，氮气处理对不同虫态烟草甲的防治效果差异显著，对卵和成虫的防治效果高于其他虫态。99%浓度氮气在20、25、30℃条件下处理烟草甲卵4 d，99%浓度氮气在30℃条件下处理烟草甲成虫4 d，校正死亡率即可达100%；实仓条件下，99%浓度氮气处理密闭烟垛9 d，对烟草甲幼虫、蛹、成虫的校正死亡率可达100%。因此，20~30℃条件下，运用氮气杀虫技术可有效防治烟仓中各虫态烟草甲，温度越高、氮气浓度越大效果越好。

Control Efficiency of Nitrogen Gas on Lasioderma serricorne (Fabricius) in Stored Tobacco

The objective of this investigation was to study the effects of nitrogen gas on Lasioderma serricorne (Fabricius) at different developmental stages (larva, pupa, adult, and egg) under the conditions of laboratory and real storage. In the laboratory, L. serricorne of the four developmental stages were treated with 95% and 99% nitrogen gas at 20, 25, and 30 ℃. After 1, 2, 4, 6, 8, 10, 12, and 14 days, the concentration of nitrogen was measured and mortality was recorded. Under real storage conditions, 99% nitrogen gas was used to treat L. serricorne in a closed stack and mortality was recorded after 9 and 30 days. The experiments were designed in three replicates. The six combined treatments had certain lethal effects on L. serricorne under the experimental conditions, and mortality increased with the increase in nitrogen concentration, temperature, and duration of treatment. In addition, nitrogen had significant effects on L. serricorne of different developmental stages, especially eggs and adults. When eggs were treated with 99% nitrogen at 20, 25, and 30 ℃ for 4 days, and adults were treated with 99% nitrogen at 30 ℃ for 4 days, the mortality reached 100%. Under real storage conditions, when 99% nitrogen was used to treat the closed stack for 9 days, the mortality of larvae, pupa and adults of L. serricorne all reached 100%. The findings of this study suggest that nitrogen gas can effectively control L. serricorne in tobacco storage and is more effective at elevated temperature and nitrogen concentration.