Abstract: To explore the host selectivity of western flower thrips (Frankliniella occidentalis, WFT) to vegetables and compare the differences among volatiles of healthy and WFTinfested host plants, the host selectivity of female thrips to six healthy and WFTinfested vegetables (cabbage, lettuce, cucumber, eggplant, celery, garlic) were determined by Y-tube olfactory, and volatiles were identified by SPME-GC/MS. Y-tube olfactory experiment results showed that the selective rate of WFT to WFTinfested garlic was only 23.3%, which indicated a significant negative response compared to clean air (P<0.01). However, when being offered a choice between other WFTinfested host odors and clean air, WFT didn’t show significant response to the odors of damaged host (P>0.05). There was no significant difference in WFT’s selectivity between healthy and WFTinfested plant of same host (P>0.05). Among pairings of WFTinfested plants, female thrips significantly preferred cabbage to celery and garlic (P<0.01), and the preference for lettuce over garlic was significant too (P<0.01). The difference between the preference to cucumber and garlic was significant (P<0.05). Compared with healthy hosts, the types of volatiles from WFTinfested plants were significantly increased, and the main changes were terpenoids and nitrides. For example, Npropylbenzamide, E-β-ocimene, (E,E)-α-farnesene were newly produced at relatively high levels in WFTinfested plants. No obvious changes in volatiles were found between healthy and WFTinfested celery and garlic, and the contents of β-myrcene and allyl disulfide were higher in celery. Our results indicated that volatiles had a great change after hosts were infested by thrips, which could provide a basis for further research on attractants and repellents.

Key words: soil property, soil fertility, afforestation areas