20种植物提取物对几种昆虫的拒食作用

Studies on Antifeedant Activity of 20 Plant Crude Extracts against Several Pest Insects

对20种植物的杀虫活性进行了初步筛选,并对有效植物中的活性成分进行了初步分离。结果表明:水仙Narcissustazettavar.chinensis和乌桕Sapiumsebiferum两种植物的提取液对菜粉蝶Pierisrapae5龄幼虫有较强的生物活性。对供饲叶碟24h后的拒食率分别为95.22%和87.12%;48h后的拒食率分别为89.64%和79.85%;7d后的校正死亡率分别为72.56%和54.62%。水仙鳞茎甲醇提取液(简称NTME)对小菜蛾Plutellaxylostella、大豆毒蛾Dasychiralocuples和枇杷黄毛虫MelanographiaflexilineataHempson也有非常强的拒食活性。水仙鳞茎中的活性成分主要存在于乙酸乙酯相中,浓度为3.0mg/mL时,对小菜蛾3龄幼虫24h和48h后的拒食率分别为94.89%和89.78%。

The insecticidal activity of 20 plant extracts against the 5th instar larvae of Pieris rapae were tested and the active ingredients of effective plants were separated primarily.The results showed that the extracts of Narcissus tazetta var. chinensis and Sapium sebiferum had very strong bioactivities against the 5th instar larvae of P. rapae.Antifeeding rate in 24 h reached 95.22% and 87.12% respectively, antifeeding rate in 48 h reached 89.64% and 79.85% respectively,corrected mortality in 7 d reached 72.56% and 54.62% respectively. Methanol extract of N. tazetta var. chinensis bulbs also had very strong antifeedant activity against Plutella xylostella,Dasychira locuples and Melanographia flexilineata Hempson. The active ingredient in N. tazetta var. chinensis bulbs mainly existed in the extract of ethyl acetate and at the concentration of 3.0 mg/mL,antifeeding rate in 24 h and 48 h reached 94.89% and 89.78% respectively.