肉桂醛对赤拟谷盗的熏蒸作用及对成虫保护酶活性的影响

为明确肉桂醛对赤拟谷盗Tribolium castaneum各发育阶段的杀虫活性及对成虫几种保护酶活性的影响, 本试验采用三角瓶密闭熏蒸法测定了肉桂醛对赤拟谷盗低龄幼虫、高龄幼虫、蛹和成虫的熏蒸作用及24 h致死中浓度熏蒸后成虫体内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性。结果表明, 肉桂醛的熏蒸效果与其浓度和赤拟谷盗发育阶段有关, 肉桂醛2.5 μL/L熏蒸72 h对赤拟谷盗成虫的熏蒸效果最好, 幼虫次之。在24 h致死中浓度处理下, 赤拟谷盗成虫体内SOD、POD、CAT活性分别在48、12 h和36 h达到最高, 其活性分别为对照的2.70、1.03倍和1.96倍。随着熏蒸时间的延长, 成虫POD活性在处理36 h后低于对照, SOD、CAT活性分别在处理36~60 h和24~48 h显著高于对照。综上所述, 经肉桂醛熏蒸处理后, 赤拟谷盗成虫体内动态平衡受到破坏, 进而产生毒害作用。因此, 肉桂醛对赤拟谷盗的生物防治有较高的应用价值。

Effects of cinnamaldehyde on fumigation and protective enzyme activity in Tribolium castaneum adults

To determine the insecticidal activity of cinnamaldehyde against Tribolium castaneum at various developmental stages and its impact on several protective enzymes in T. castaneum adults, the fumigation effect of cinnamaldehyde on young larvae, old larvae, pupae, and adults were investigated using a conical flask fumigation method, and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in the adults exposed to cinnamaldehyde at a median lethal concentration (LC 50) were measured. The results showed that the fumigation effect was correlated with the concentration of cinnamaldehyde as well as the developmental stage of T. castaneum. After exposed to 2.5 μL/L of cinnamaldehyde for 72 h, the best fumigation effect was observed on the adults, followed by the larvae. The activities of SOD, POD, and CAT reached the highest level when treated with LC 50 (24 h) of cinnamaldehyde for 48, 12 h, and 36 h, respectively; the activities of SOD, POD, and CAT were 2.70-, 1.03-, and 1.96-fold of those in the control group, respectively. The POD activity in treated adults was lower than that in the control group when fumigated for 36 h, while SOD and CAT activities were significantly higher than those in the control group when insects were fumigated in flask for 36-60 h and 24-48 h, respectively. In conclusion, cinnamaldehyde fumigation can destroy the dynamic balance in T. castaneum in vivo, resulting in toxic effects. Therefore, cinnamaldehyde has the potential for biological control of T. castaneum.