松油烯-４-醇对粘虫幼虫的生物活性

测定了杀虫植物砂地柏Sabina vulgaris Ant.的精油中主杀虫成分-松油烯-4-醇（terpinen 4.01）对粘虫Mythimna separata Walker幼虫的生物活性。结果表明，松油烯- 4-醇对粘虫主要表现为熏蒸作用，对粘虫3龄幼虫24 h的熏蒸LC₅₀为5.3473 μL/L ；还具一定触杀作用，对粘虫4龄幼虫24 h的LD₅₀为147.8 μg/虫。试虫的中毒症状可明显地分为兴奋、痉挛、麻痹和死亡4个阶段，而麻痹的部分试虫有复苏现象。可明显抑制Na⁺ ,K⁺ATP酶的活性，在兴奋期、痉挛期、麻痹期和复苏期，抑制率介于21.28%～34.92% 之间。离体条件下对Na⁺,K⁺ATP酶的I₅₀为133.75 μg·mL^-1；对AChE活性有一定的影响；对酯酶，在兴奋期，酶活力为对照的7.0%，在麻痹期则为对照的1.33倍，而复苏期试虫的酯酶活力与对照相当。

Insecticidal activity of terpinen-4-ol against larvae of the oriental armyworm,Mythimna separata (Walker) (Lepidoptera:Noctuidae)

Terpinen-4-ol is the main insecticidal composition in essential oil of Sabina vulgaris Ant.，an insecticidal plant. The toxicity, poisoning symptoms and biochemical effects of terpinen-4-ol on larvae of the oriental armyworm, My thimna separata (Walker) were assayed. The results showed that terpinen-4-ol was very toxic to 3-instar larvae of the armyworm with fumigating application (LC₅₀=5.3473 μL·L^-1)and the LD₅₀ of contact activity to-4-instars larvae of the armyworm was 147.8 μg/larvae. The poisoning symptom caused by the compound could be divided into4-stages, i.e., excitation, convulsion, paralysis and death; but some paralyzed insects could recover. In vivo, the activity of Na⁺,K⁺-ATPase in brain of 5th instar larvae tested was inhibited; the inhibition ratio was 21.28% in exciting stage, 25.62% in convulsing stage, 32.10% in paralysis stage, and 34.92% in recovering stage, respectively. In vitro, the I₅₀ of Na⁺,K⁺-ATPase was 133.75 μg·mL^-1(Y=2.2236+1.3058X r=0.988, χ² =1.26). It had certain influence on the activity of AChE. In the excitation stage, the activity of ester enzyme of the treated larvae was 77.0% of that of the control; in the paralysis stage, it was 1.33 times; but it was as high as that of the control in the recovery stage.