长足大竹象的触角超微结构和对竹笋挥发物的触角电位反应

长足大竹象Cyrtotrachelus buqueti Guerin-Meneville是当前竹林主要害虫, 专一地取食危害丛生竹笋梢。本研究应用电镜扫描、气质色谱联用(GC-MS)及触角电位(EAG)技术, 分析了长足大竹象成虫触角的超微结构、不同竹笋挥发物的成分及其与成虫的触角电位反应, 以期分析长足大竹象寡食竹笋的原因。结果表明长足大竹象成虫触角上感知竹笋挥发物的锥形感器数量最多、密度最大。气质色谱联用在竹笋挥发性物质中检测到28种物质, 醛类物质相对含量最高, 其次是醇类和酸类物质。EAG分析表明苯甲醛等13种竹笋挥发物的相对触角电位值显著高于对照, 以苯甲醛的EAG值最高。结果提示丛生竹笋梢高含量和特有的挥发物成分可能是吸引长足大竹象取食竹笋的重要物质, 长足大竹象对竹笋气味的识别很大可能是根据以苯甲醛为主要成分组成的、具有特定成分比例的化学指纹图谱。本研究为研制长足大竹象取食引诱剂提供了理论依据。

Antennal ultrastructure and electroantennogram responses of Cyrtotrachelus buqueti Guerin-Meneville(Coleoptera:Curculionidae)to volatiles of bamboo shoot

Cyrtotrachelus buqueti Guerin-Meneville, a main bamboo pest, specializes in boring and damaging the top of tufting bamboo shoot. For analyzing the reason, the antennal ultrastructure of C. buqueti and the volatiles of different bamboo shoots and the antennal olfactory responses of female to the volatiles were studied with the scanning electron microscoopy and the gas chromatographic-mass spectrometry (GC-MS) and the electroantennogram (EAG), respectively. The results showed that the sensilla basiconica, with the ability of apperceiving the volatiles of bamboo shoot, was the most sensilla on the antenna of C. buqueti, and 28 bamboo shoot volatile compounds from bamboo shoot were discovered by GC-MS, in which the relative content of aldehydes was the highest, and those of alcohols and acids come second. The EAG analysis deduced that the relative EAG values of benzaldehyde with the highest relative EAG values and other 12 volatiles were significantly higher than the control. These results suggest that the high content or the special volatiles of the top of tufting bamboo shoot might be the important odor signals which allure C. buqueti to tend towards the top of bamboo shoot, and that C. buqueti might identify the bamboo shoot by the chemistry finger map with primary benzaldehyde and special proportion of components. This study provides a theoretical basis for developing attractant of C. buqueti.