Behavioral responses of Empoasca vitis G?the tovolatiles from tea shoots
Author of the article:WANG Meng-Xin LI Hui-Xian WU Wen-Zhu SUN Hai-Chao SHI Song-Ping DING Yuan CAO Chun-Hui HAN Bao-Yu
Author's Workplace：Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China
Key Words：tea green leafhopper, tea shoot volatiles, attractant, behavioral responses
Abstract：
[Objectives] To determine the behavioral responses of the tea green leafhopper (Empoasca vitis Göthe) to volatile compounds emitted by both intact, and leafhopper-damaged, tea shoots in order to identify volatiles that attract this pest. [Methods] Volatiles from intact and leafhopper-damaged tea shoots were adsorbed by the routine overhead entrained air method, eluted in organic solvent, concentrated under a small flow of pure nitrogen, and qualitatively and quantitatively analyzed. The responses of leafhoppers to different volatiles were assessed in a Y-tube olfactometer. [Results] Thirty components in the volatiles of both intact, and leafhopper-damaged, tea shoots were identified in which the alkene content was relatively high. A total of 13 compounds were identified in the volatiles of intact and leafhopper-damaged tea shoots. The amounts of these compounds were considerably greater in volatiles emitted by leafhopper-damaged tea shoots than those emitted by intact tea shoots, especially (Z)-b-ocimene and (Z)-3-hexenyl acetate, which were respectively 142.27 and 12.90 times higher in volatiles from leafhopper-damaged tea shoots than in those from intact tea shoots. Twelve different compounds were identified in the volatiles of leafhopper-damaged tea shoots, among which perillene was particularly abundant. At concentrations of 10-2, 10-4, and 10-6 g/mL, (Z)-3-hexenyl acetate was significantly attractive to leafhoppers. Perillene was also significantly attractive at concentrations of 10-2 g/mL and 10-4 g/mL, (Z)- b-ocimene, as was (D)-limonene at 10-4 g/mL and 10-6 g/mL, linalool at 10-4 g/mL and n-butyl acetate at 10-6 g/mL. Two mixtures of different compounds were also significantly attractive, however, 10-6 g/mL of α-farnesene was not attractive to leafhoppers (P<0.05). [Conclusion] Adult tea green leafhoppers display different behavioral responses to components of the volatiles of intact tea shoots compared to those from leafhopper-damaged tea shoots. Identifying single component, or mixture of components, of volatiles that attract leafhoppers can provide a basis for field experiments.