4种抗虫性植物水提物对棉蚜取食行为的影响

通过拒食活性的生物学观察和刺吸电位技术(EPG)研究了夹竹桃、香樟、银杏和番茄等4种植物的鲜叶水溶性提取物对棉蚜取食行为的影响.结果表明:4种植物的水溶性粗提液和氯氰菊酯具有明显的拒食效应,而且拒食效果随着浓度的提高和作用时间的延长而提高,但当作用时间从2 h增加到4h时,香樟、番茄水溶性粗提液对棉蚜的拒食效果却明显下降.因此,香樟和番茄水溶性粗提液中起拒食驱避作用的成分很可能具挥发性.EPG分析显示:4种粗提液和氯氰菊酯使棉蚜有效取食(E1、E2和G波)的持续时间极显著地缩短,E1、E2波持续时间分别缩短至对照的29%以下和23%以下,G波持续时间缩短至对照的56%以下;寻找取食部位(C波)的持续时间显著延长,而此过程中棉蚜口针短暂穿刺植物细胞膜(pd波)的频率明显减少;除香樟外,还极显著地延长棉蚜的非取食行为(np波)的持续时间(2倍以上).因此,与氯氰菊酯一样,夹竹桃、香樟、银杏和番茄等4种植物的鲜叶水溶性提取物显著影响棉蚜取食行为.

The influence of four kinds of plant aqueous extracts on the feeding behaviors of Aphids gossypii

The feeding behaviors of cotton aphid,Aphids gossypii,on melon,Cucumis melo,treated with aqueous extracts of rosebay(Nerium indicum),camphor tree(Cinnamomum camphora),ginkgo(Ginkgo biloba)and tomato(Lycopersicon esculentum)were studied by usingbiological assay and electrical penetration graph(EPG).It was found that the four kinds of a-queous exacts had a stronger antifeeding effect when the concentration of aqueous exacts washigher or the feeding time was longer.However,after 2 hours,the antifeeding effect of cam-phor tree''s and tomato''s aqueous extracts declined.This was probably due to their volatile com-ponents.EPG analysis revealed that the effective feeding durations (E₁,E₂ and G)were short-ened,the seeking(C)time was prolonged and the penetration(pd)frequency during C wasreduced by these four kinds of plant''s aqueous extracts or cypermethrin significantly when A.gossypii fed on melon treated with them.These aqueous extracts and cypermethrin also prolonged non-penetration(np)time except C.camphora.So,these aqueous extracts had verysignificant effect on the feeding behavior of A.gossypii,as cypermethrin did.