Wei Jianing, Shao Wenbo, Wang Xianhui, Ge Jin, Chen Xiangyong, Yu Dan, Kang Le
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Insect Sci. 2017 Feb;24(1):60-72. doi: 10.1111/1744-7917.12396. Epub 2016 Oct 4.
Chemical communication plays an important role in density-dependent phase change in locusts. However, the volatile components and emission patterns of the migratory locust, Locusta migratoria, are largely unknown. In this study, we identified the chemical compositions and emission dynamics of locust volatiles from the body and feces and associated them with developmental stages, sexes and phase changes. The migratory locust shares a number of volatile components with the desert locust (Schistocerca gregaria), but the emission dynamics of the two locust species are significantly different. The body odors of the gregarious nymphs in the migratory locust consisted of phenylacetonitrile (PAN), benzaldehyde, guaiacol, phenol, aliphatic acids and 2,3-butanediol, and PAN was the dominant volatile. Volatiles from the fecal pellets of the nymphs primarily consist of guaiacol and phenol. Principal component analysis (PCA) showed significant differences in the volatile profiles between gregarious and solitary locusts. PAN and 4-vinylanisole concentrations were significantly higher in gregarious individuals than in solitary locusts. Gregarious mature males released significantly higher amounts of PAN and 4-vinylanisole during adulthood than mature females and immature adults of both sexes. Furthermore, PAN and 4-vinylanisole were completely lost in gregarious nymphs during the solitarization process, but were obtained by solitary nymphs during gregarization. The amounts of benzaldehyde, guaiacol and phenol only unidirectionally decreased from solitary to crowded treatment. Aliphatic aldehydes (C7 to C10), which were previously reported as locust volatiles, are now identified as environmental contaminants. Therefore, our results illustrate the precise odor profiles of migratory locusts during developmental stages, sexes and phase change. However, the function and role of PAN and other aromatic compounds during phase transition need further investigation.
化学通讯在蝗虫密度依赖性相变中起着重要作用。然而，飞蝗（Locusta migratoria）的挥发性成分和释放模式在很大程度上尚不清楚。在本研究中，我们鉴定了蝗虫身体和粪便中挥发性物质的化学成分及释放动态，并将它们与发育阶段、性别和相变联系起来。飞蝗与沙漠蝗（Schistocerca gregaria）有一些共同的挥发性成分，但这两种蝗虫的释放动态有显著差异。飞蝗群居若虫的体臭由苯乙腈（PAN）、苯甲醛、愈创木酚、苯酚、脂肪酸和2,3 - 丁二醇组成，且PAN是主要挥发性物质。若虫粪便颗粒中的挥发性物质主要由愈创木酚和苯酚组成。主成分分析（PCA）表明群居和独居蝗虫的挥发性成分谱存在显著差异。群居个体中PAN和4 - 乙烯基茴香醚的浓度显著高于独居蝗虫。群居成熟雄性在成年期释放的PAN和4 - 乙烯基茴香醚量显著高于成熟雌性以及两性的未成熟成虫。此外，PAN和4 - 乙烯基茴香醚在群居若虫的独居化过程中完全消失，但在独居若虫的群居化过程中又重新出现。苯甲醛、愈创木酚和苯酚的量仅从独居处理到拥挤处理单向减少。先前报道为蝗虫挥发性物质的脂肪醛（C7至C10），现在被鉴定为环境污染物。因此，我们的结果阐明了飞蝗在发育阶段、性别和相变过程中的精确气味特征。然而，PAN和其他芳香化合物在相变过程中的功能和作用需要进一步研究。
