黏虫幼虫体表挥发物成分鉴定及其对中红侧沟茧蜂寄主定位行为的影响

为提高中红侧沟茧蜂Microplitis mediator田间寄生效率,对黏虫Mythimna separata 1～5龄幼虫体表挥发物进行提取,采用气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）技术对其成分进行分析,采用气相色谱-触角电位（gas chromatography-electron antenneal detection,GCEAD）技术确定引起中红侧沟茧蜂触角电位（electroantennogram,EAG）反应的挥发性物质,同时通过Y型嗅觉仪测定中红侧沟茧蜂对其的选择反应。结果显示,中红侧沟茧蜂雌成蜂对黏虫1～3龄幼虫体表粗提物有显著的选择反应,反应率分别为60%、68%和56%;中红侧沟茧蜂触角对黏虫体表粗提物中的2,4-二甲基庚烷、5-乙基-2-甲基辛烷、十二烷、1,3-二叔丁基苯、2,4-二甲基十一烷、十六烷、2,6,10,15-四甲基十七烷和抗坏血酸二棕榈酸酯10种物质均有电生理反应,EAG反应随浓度升高而增强;中红侧沟茧蜂雌雄成蜂对这10种物质的选择反应存在性别差异;其中中红侧沟茧蜂对其中的8种物质及...

Volatile components from the body surface of oriental armyworm Mythimna separata larvae and their effects on the host location behavior of parasitoid wasp Microplitis mediator

In order to improve the parasitic efficiency of parasitoid wasp Microplitis mediator in the field, volatiles were extracted from the body surface of the 1st-5th instar larvae of oriental armyworm Mythimna separata. Gas chromatography-mass spectrometry (GC-MS) was carried out to analyze the volatile components of the body extracts. Gas chromatography-electron antenneal detection (GC-EAD) was used to detect the volatile components that could trigger electroantennogram (EAG) response from the antennae of M. mediator. The selection behavior experiment of M. mediator to the determined volatiles was conducted by using Y-type olfactometer. The results showed that the extracts from the body of the 1st to 3rd instar M. separata larvae had a significant attraction effect on the female bees, and the response rates were 60%, 68% and 56%, respectively. The antennae of M. mediator had electrophysiological reactions to ten components in the body extracts of M. separata, including 2,4-dimethylheptane, 2,5- dimethylnonane, 5-ethyl-2-methyloctane, dodecane, 1,3-di-tert-butylbenzenehyl, 2,4-dimethyl-undecane, hexadecane, eicosane, 2,6,10,15-tetramethylheptadecane and l-(+)-ascorbic acid 2,6-dihexadecanoate. EAG results showed that the electrophysiological response of M. mediator antennae increased with increasing concentrations and there were differences between males and females. Among the ten identified components, eight of them had significant attractant effect on M. mediator. The simulated mixture of extracts from 1st to 3rd instars had significant attraction effects on M. mediator. Therefore, ten components mentioned above were identified as the semiochemical compounds for host location in M. mediator.