与中红侧沟茧蜂生境与寄主定位相关的玉米及棉铃虫幼虫体表挥发性成分的提取与鉴定

【目的】鉴定玉米Zea mays L.和棉铃虫Helicoverpa armigera (Hübner)幼虫体表挥发性成分中对中红侧沟茧蜂 Microplitis mediator (Haliday)具有生境与寄主定位作用的信息化合物，从化学生态学的角度研究玉米-棉铃虫-中红侧沟茧蜂三重营养关系，解释中红侧沟茧蜂寻找寄主的过程中的信息识别机制，为害虫的综合防治的“推-拉”方法提供一定的理论基础。【方法】利用触角电位仪(EAG)、触角电位联用仪(GC-EAD)、气质联用仪(GC-MS)及“Y”型嗅觉仪确定玉米和棉铃虫幼虫体表提取物的信息化合物。在室内利用玉米以及棉铃虫幼虫体表挥发物标准品化合物以及模拟混合物，使用“Y”型嗅觉仪进行中红侧沟茧蜂成虫行为反应试验。【结果】玉米挥发物中有11种化学成分，棉铃虫幼虫体表挥发物中有6种化学成分对中红侧沟茧蜂的触角具有电生理活性，其中4种成分在两种挥发物中都存在。室内行为反应试验发现：与正己烷对照相比，玉米的模拟组分对雌、雄蜂均表现出显著（P<0.05）的诱引作用；棉铃虫1龄幼虫体表模拟组分对雌蜂具有极显著的诱引作用（P<0.01），对雄蜂具有显著的诱引作用（P<0.05）；棉铃虫2龄幼虫体表模拟组分对雌蜂具有显著的诱引作用（P<0.05）。【结论】本研究证明了玉米以及棉铃虫幼虫体表挥发物中分别存在11种（庚醛、2-己醇、1-己醇、1-辛烯-3-醇、壬醛、葵醛、苯甲醛、反式-2-壬烯-1-醇、己酸、苯基乙醇、月桂醇）和6种（2-己醇、己酸乙酯、1-己醇、壬醛、辛酸乙酯、癸醛）中红侧沟茧蜂生境及寄主定位的化学信息物质。

Extraction and identification of maize volatiles and cuticular volatiles of larval Helicoverpa armigera (Lepidoptera: Noctuidae) related to host habitat location and host location of parasitic wasp Microplitis mediator (Hymenoptera: Braconidae)

【Aim】 This study aims to identify maize ( Zea mays L.) volatiles and cuticular volatiles of larval Helicoverpa armigera (Hübner) for host-habitat location and host location of Microplitis mediator (Haliday). The tritrophic interaction among maize, H. armigera, and M. mediator was investigated in the context of chemical ecology, and the mechanisms of chemical communications in host location of M. mediator were illustrated. The work has some implications for the “pull-push” approach in integrated pest management.【Methods】 Semiochemicals from maize volatiles and cuticular volatiles of H. armigera larvae were identified by using electroantennogram (EAG), gas chromatographic-electroantennographic detection (GC-EAD), gas chromatograph-mass spectrometer (GC-MS), and Y tube olfactometer test equipment. Standard semiochemicals and the mimetic compounds of maize volatiles and cuticlular volatiles of H. armigera larvae were used to test behavioral responses of M. mediator with Y-tube olfactometer in the laboratory.【Results】 Tested by GC-MS and GC-EAD, totally 11 compounds of maize volatiles and 6 compounds from cuticular volatiles of H. armigera larvae were found to be electrophysiologically active, of which 4 electrophysiologically active compounds were identified from both maize volatiles and cuticular volatiles of H. armigera larvae. Behavioral response tests in the laboratory showed that compared with the control of n-hexane male and female wasps were significantly attracted to the mimetic compounds of maize volatiles (P<0.05). Female wasps were significantly attracted to the mimetic compounds of cuticular volatiles of the 1st instar (P<0.01) and the 2nd instar larvae of H. armigera (P<0.05). Male wasps were significantly attracted to the synthesized compounds of cuticular volatiles of the 1st instar larvae of H. armigera (P<0.05). 【Conclusion】 These results demonstrated that 11 compounds (heptanal, 2-hexanol, 1-hexanol, 1-octen-3-ol, nonanal, decanal, benzaldehyde, E-2-nonen-1-ol, hexanoic acid, phenyethyl alcohol, and 1-dodecanol) from maize volatiles and six compounds (2-hexanol, ethyl hexanoate, 1-hexanol, nonanal, ethyl caprylate, and decanal) from cuticular volatiles of H. armigera larvae are responsible for host-habitat location and host location of M. mediator.