| By using the model of tea plant-green leathopper-predatory spider, thephysical and chemical mechanism of green 1eafuopper's orientation to tea plants,spider's orientation to tea plants and green leafuoppers were investigated from thevieWPoint of chemical ecology. The investigation on the sounding produced andsound communication between green 1eathopper sexes were also conducted-According to the result of morphological investigation of the tea greenleathopper specimen from Zhejiang, Fujian, AIiliui, Hubei, Hunan, Guizhou,Guangdong and Hainan provinces, the dominant species of tea green leafuopper inthese tea areas was EmPoasca (EmPoasca) vitis (G6the) rather than EmPoascaj7avescens (Fabricius), with Which we deduced that even if EmPoasca j7avescens(Fabricius) existed, they also were llot dominant species.With Tenax TA. the volatiles of intact tea shoots (IS), mechanically damagedtea shoots (MDS) and tea plant-green leafoopper feeding complexes (PHCs) wereabsorbed, and the GC-MS results were as followings:The volatiles emitted from intact tea shoots were composed of l lcompounds,the compounds wth higher concentration were respectively (Z)-3,7Aiimethy-1 .3,6-octatriene, 4-methy1-l,5-heptadiene, (Z, Z, Z)-9, l2, l5-octadecatrienoicacid,methyl ester, l-penien-3-ol and indole; those with lower concentration wererespectively (Z)~3-hexen-l-ol,acetate, (E)-2-hexenal and (E)-3,7-dimethyl -l,3,6-octatriene, (E)-3,7-dimethyl-2,6-octadien-l -ol,3,7-dimethyl-l,6-octadien-3-ol, (Z)-3-hexen-1-ol and there were 3 udriown compounds.Mechanically damaged tea shoots volatiles had l0 compounds. The followingcompounds were found, about which lacked in intact tea shoots: (Z)-butanoic acid,3-hexenyl ester, hexanoic acid,3-hexenyl ester, 3,6-dimethyl-l,5-heptadiene. ThefOllowing compounds existed in the intact tea shoots, however were lacked in theMDS: 4-methyl-l,5-heptadiene, illdole, l-penten-3-ol, (Z, Z, Z)-9,12,l5-octadecatrienoic acid, methyl ester- The concentration of those components werehigher than those in the intact tea shoots: (E)-2-hexenal, (Z)-3-hexen-1-ol,acetate,(Z)-3,7-dimethyl-l,3,6~octatriene. While (E)-3,7-dimethyl-l,3,6-octatrie (E)-3,7-dimethyl-2,6-octadien- l -ol, 3,7-dimethyl- l,6-octadien-3-ol, (Z)-3-hexen- l -olwere existed in the similar concentration in the volatile collection of both shootsand there were also 3 unknown components.There were nine compounds in tea plant-green 1eafuopper feeding complexes.The following compounds were lacked in the iniact tea shoots: 3,6-dimethyl-l,5-heptadiene, 4-hexen-1 -ol,acetate and 2,6-dimethyl-3,7-octadiene -2,6-diol.The concentration of those compounds including indo1e, (E)-2-hexenal, 3,7-dimethyl-1,6-octadien-3-ol were higher than those in the volatile collection ofintact tea shoots. And the compound (Z)-3,7-dimethyl-1, 3, 6-octatriene was lower.(E)-3,7-dimethyl-l,3,6-octatrie l-pellten-3-ol were not detected in the PHCsvolatiles and (E)-3,7-dimethyl-2,6-octadien-1 was existed in similarconcentration.By using the T-shaPed, Square- and hexagon-shaPed test chamber, theorientational responses of green leafuoppers to tea shoots. tea shoots vo1atiles andthe preference to different colors were tested respectively, the colors selected testalso be conducted in the tea field.The results of T-shaPed test chamber showed that, when lighting, the greenleafuopper were attracted to lightness firstly, the amounts of leaffiopper on hostplant were much more higher than those on non- host plant when both of them inlighting state, the amoullts were no significant difference between them. When hosttea plant was far from light resource, the amoullts of leathopper on it were muchlower than those on the non-host plant under light source. These showed that therole of lightness to orientational response of green leafaopper was more significanthan that of odor, and these two factors showed synergic effect.Experimellts on the square test chamber... |
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