Abstract:  【Aim】 This study aims to explore the effects of feeding of the alien invasive pest Dysmicoccus neobrevipes on the composition of volatiles from host plants, and to analyze the volatile-mediated behavioural mechanism of D. neobrevipes on host plants, so as to provide a reference for the selection and breeding of insect-resistant host varieties, and for the research and development of D. neobrevipes and its natural enemy insect regulators.【Methods】 The volatiles released from four host plants including sisal, pineapple, banana and pumpkin were collected by dynamic headspace adsorption (DHSA) method at different time post infestation by D. neobrevipes adults (0, 1, 2, 4 and 8 d). The similarities and differences of volatile components and content changes in different host plants before and after being damaged by feeding of D. neobrevipes adults were identified and analyzed by gas chromatography-mass spectrometry (GC-MS). At the same time, a Y-tube olfactometer was used to further study the tactic responses of D. neobrevipes adults to nine single compounds. 【Results】 There were nine compounds in four classes of volatile components from healthy sisal plants and 12 compounds in five classes from adult D. neobrevipes-infested (insect-infected) sisal plants, eight compounds in four classes from healthy pineapple plants and 11 compounds in five classes from insect-infected pineapple plants. All six classes of compounds obtained from healthy pumpkin plants were present in the insect-infected pumpkin plants. There were 11 compounds in five classes from healthy banana plants and 15 compounds in seven classes from insect-infected banana plants. In the healthy and insect-infected plants of sisal and pineapple, the relative content of ketones was the highest; in the healthy and insect-infected plants of pumpkin, the relative content of ethers was the highest; and in the healthy and insect-infected plants of banana, the relative content of alkanes was the highest. 4, 6-Dimethyl dodecane and naphthalene are unique volatile organic compounds (VOCs) of sisal and herbivore-induced plant volatiles (HIPVs) of pineapple, respectively. Nine new VOCs including 3-hexanone, 2-hexanone, (+)-limonene, 3-carene, 4-(1-hydroxyethyl) benzaldehyde, 2-isopropyl-5-methylanisole, naphthalene, p-ethylacetophenone and cedrol were found in the volatiles from the host plants damaged by D. neobrevipes adults, as compared with the volatile compounds emitted from healthy plants. Among them, 4-(1-hydroxyethyl) benzaldehyde, pethylacetophenone and cedrol could effectively attract D. neobrevipes adults, while compounds such as (+)-limonene, 3-carene, 2-isopropyl-5-methylanisole and naphthalene had repellent effects on D. neobrevipes adults, indicating that these compounds were the main factors affecting the interaction between host volatiles, D.neobrevipes and natural enemy insects. 【Conclusion】 The discovery of nine new HIPVs provides a theoretical basis for the development of new repellents and natural enemy insect attractants for D.neobrevipes and the use of regulators to control the pest.

Key words: Dysmicoccus neobrevipes, host plant, volatiles, tactic responses, cluster analysis