Seenivasagan T, Paul A V Navarajan
Division of Entomology, Indian Agricultural Research Institute, New Delhi 110 012, India.
Indian J Exp Biol. 2011 May;49(5):375-86.
Saturated hydrocarbons (SHC) of five cruciferous host plants viz., cabbage, cauliflower, broccoli, knol khol and Brussels sprout and the larvae of diamondback moth (DBM), Plutella xylostella reared on these host plants were identified through gas-chromatography. The hydrocarbon profile of host plants and larval body extract of DBM reared on respective host plants revealed a wide variation in quantity as well as quality. Long chain hydrocarbons C26-C30 were detected in all the extracts. In electroantennogram (EAG) studies, SHCs at 10(-3) g dose elicited differential EAG response in the antennal receptors of gravid Cotesia plutellae females. Tricosane (C23) and hexacosane (C26) elicited 10-fold increased EAG response compared to control stimulus. Long chain hydrocarbons C27, C28 and C29 elicited, 6-7 fold increased responses. The sensitivity of antenna was 4-5 folds for C25, C14, C24, C15 and C30, while the short chain hydrocarbons elicited 2-3 fold increased EAG responses. Dual choice flight orientation experiments in a wind tunnel revealed that the gravid C. plutellae females preferred the odour of C16, C26, C29, C15, C21, C23, C30, C27, C24 and C22 as 60-70% females oriented and landed on SHC treated substrate compared to control odour, while the odour of eicosane (C20), pentacosane (C25) and octacosane (C28) were not preferred by the females.
通过气相色谱法鉴定了五种十字花科寄主植物（即卷心菜、花椰菜、西兰花、球茎甘蓝和抱子甘蓝）以及取食这些寄主植物的小菜蛾幼虫体内的饱和烃（SHC）。寄主植物和取食相应寄主植物的小菜蛾幼虫体提取物的烃类图谱显示，在数量和质量上都存在很大差异。在所有提取物中均检测到长链烃C26 - C30。在触角电位（EAG）研究中，剂量为10(-3) g的饱和烃在孕茧蜂雌性触角感受器中引发了不同的EAG反应。与对照刺激相比，二十三烷（C23）和二十六烷（C26）引发的EAG反应增加了10倍。长链烃C27、C28和C29引发的反应增加了6 - 7倍。对于C25、C14、C24、C15和C30，触角的敏感性提高了4 - 5倍，而短链烃引发的EAG反应增加了2 - 3倍。在风洞中进行的双选飞行定向实验表明，孕茧蜂雌性更喜欢C16、C26、C29、C15、C21、C23、C30、C27、C24和C22的气味，与对照气味相比，60 - 70%的雌性定向并降落在经饱和烃处理的基质上，而雌性不喜欢二十烷（C20）、二十五烷（C25）和二十八烷（C28）的气味。
