Abstract:

With GC-MS,the composition and relative contents of the volatiles in three kinds of leaves of Castanea mollissima BL. Were analyzed:uninfested leaves, infested leaves with Oligonychus ununguis, and infected leaves without the mites. Caryophyllene and Alpha-fanesene were of large proportion in all the three kinds of leaves. Peak of the Caryophyllene was higher in the infested leaves, while that of the Alpha-fanesene was higher in the infested leaves without mites. 1-octene was not found in the uninfested leaves, but was found of high content in the infested leaves, and the peak of it in these leaves with mites was higher significantly than in those without mites. Peak of Benzoic acid ethyl ester in the infested leaves with mites was higher significantly than in the other two kinds of leaves. Content of 1,6,10-doclecatrien-3-ol, 3,7,11-trimethyl was highest in the infested leaves with mites, while there were little of it in the uninfested leaves. 4-bromo-2-bentenl showed the opposite trend:the content of it in the uninfested leaves was higher significantly than in the infested leaves. It was inferred from the biological test that:having been infested, the change of the kinds and content of the volatiles changed the chemical fingerprint of the host plants' odor so that Oligonychus ununguis had difficulty in recognizing its host plants even had epellent action and migrated from the infested leaves to the uninfested leaves. At the same time, these volatiles have important inducement action in attracting Amblyseius finlandicus.

Key words: Oligonychus ununguis, Amblyseius finlandicus, semiochemica, inducement action, repellent action