Abstract:

【Aim】 The oviposition deterrence of herbivore-induced plant volatiles (HIPVs) from cotton plants damaged by the larvae of the turnip moth, Agrotis segetum, was evaluated on conspecific females, and the composition and functions of the major HIPVs were characterized in this study in order to identify the active components attracting or deterring adult oviposition.【Methods】 We identified HIPVs from cotton plants damaged by A. segetum larvae using a gas chromatography-mass spectrometer (GC-MS) and evaluated the electrophysiological activity and oviposition deterrent bioactivity of the major HIPVs to female adults of A. segetum using the electroantennogram (EAG) and oviposition cage bioassay method, respectively.【Results】 The female adults of A. segetum preferred to lay eggs on the healthy cotton plants over the damaged cotton plants, and the number of eggs laid on the healthy cotton plants was 6.59 times as high as that on the damaged cotton plants by A. segetum larvae. The HIPVs emitted from the cotton pants damaged by A. segetum larvae mainly consisted of benzaldehyde, linalool, β-caryophyllene, humulene, tetradecane, hexadecane, etc. Among them, benzaldehyde and linalool elicited strong EAG responses on the female antennae, showing a dose-response pattern. In the oviposition cage bioassay, linalool significantly deterred oviposition of female adults of A. segetum, while benzaldehyde attracted female adults to oviposit. 【Conclusion】 HIPVs emitted from cotton plants damaged by A. segetum larvae significantly deter oviposition of conspecific females, and linalool is considered as a potential oviposition deterrent.

Key words: Agrotis segetum, cotton, herbivore-induced plant volatiles, electrophysiological response, oviposition selection, deterrent effect