摘  要  【目的】 草地贪夜蛾Spodoptera frugiperda Smith是我国重要的农林业害虫。本研究旨在明确健康、机械损伤和受幼虫为害棉花在第1天、第2天和第3天3个时间段内挥发物组分的变化，以及草地贪夜蛾雌成虫对3种状态棉花的产卵选择。【方法】 室内实验观察草地贪夜蛾成虫在不同时间段内对3种不同处理棉花的产卵选择；采用顶空吸附法收集健康、机械损伤和受害后不同时间段内的挥发物，然后用气相色谱-质谱联用技术分析挥发物成分及释放量；最后利用主成分分析和聚类分析解释挥发物成分的变化。【结果】 雌成虫第1天内在健康棉花上的卵块数及产卵量显著多于机械损伤和虫害棉花，但3种状态间在第2天和第3天没有差异。同时，雌成虫第1天内在健康棉花上的卵块数及产卵量显著多于第2天和第3天。在不同处理的棉花挥发物中共鉴定出25种成分，不同处理间挥发物在第1天内差异最大，机械损伤和虫害植株释放的挥发物种类与含量明显多于健康植株。健康植株中仅存在1-癸炔和苯甲醛两种成分；机械损伤植株中鉴定出11种成分，其中仅正辛醛和十九烷醇为特有成分；虫害植株第1天内产生大量萜烯类物质，而后随时间延长由虫害诱导的挥发物含量逐渐降低。虫害棉花挥发物的变化与柠檬烯、(3E)-4,8-二甲基-1,3,7-壬二烯、芳樟醇、吲哚、β-罗勒烯和β-石竹烯等14种成分密切相关。【结论】 健康棉花吸引草地贪夜蛾成虫产卵，而虫害棉花驱避草地贪夜蛾成虫的产卵。推测1-癸炔和苯甲醛在吸引草地贪夜蛾成虫产卵行为中发挥关键作用，虫害棉花释放的特有成分如(3E)-4,8-二甲基-1,3,7-壬二烯、芳樟醇和吲哚等在驱避产卵行为中发挥关键作用。

Abstract  [Objectives]  To investigate the effect of changes in the volatile components of cotton plants on the oviposition behavior of adult female Spodoptera frugiperda Smith, an important agricultural and forestry pest in China. [Methods]  Adult female S. frugiperda were allowed to choose between volatiles collected from healthy, mechanically damaged or insect damaged, cotton plants under laboratory conditions. Volatile samples were collected from cotton plants using the dynamic headspace adsorption technique at 3 different time periods. The chemical identities of the volatile components and their contents were analyzed by gas chromatography-mass spectrometry (GC-MS). Qualitive and quantitative changes in volatile components were further analyzed by principal component analysis (PCA) and cluster analysis (CA). [Results]  Significantly more egg masses and eggs were laid on healthy plants than on mechanically damaged, or caterpillar damaged, plants on the 1st day. However, no significant preference was apparent on the 2nd and 3rd day. Significantly more egg masses and eggs were laid by adult females on the 1st day compared to the 2nd and the 3rd day. A total of 25 compounds were identified in volatiles from all three kinds of plants and plants that had been subject to mechanical or caterpillar damage produced a higher number of volatile compounds with more diverse components than undamaged plants on the 1st day. Eleven compounds were identified in mechanically damaged cotton. Octanal and 1-nonadecanol were characteristic components of the volatiles of damaged plants, whereas only 1-decayne and benzaldehyde were detected in those from healthy cotton. Large amounts of terpenes were released from caterpillar-damaged cotton on the 1st day, after which the amount gradually decreased. Changes in the composition of volatiles released by caterpillar-damaged cotton were attributed to changes in the ratio of 14 compounds, such as limonene, (3E)-4,8-dimethyl-1,3,7-nonadiene, linalool, indole, β-ocimene and β-caryophyllene. [Conclusion]  Healthy cotton attracted more female S. frugiperda whereas caterpillar-damaged cotton appeared to inhibit oviposition. It is possible that the 1-decayne and benzaldehyde released by healthy cotton plays an important role in attracting female moths for egg-laying, whereas the different volatiles released by caterpillar-damaged cotton, such as (3E)-4,8-dimethyl-1,3,7-nonadiene, linalool and indole, repel females.