| The lychee stink bug, Tessaratoma papillosa (Drury) (Hemiptera:Pentatomidae), is an important pest of the lychee tree Litchi chinensis Sonn. and the longan tree Dimocarpus longana Lour.. This dissertation dealed with the interactions between L. chinensis and T. papillosa. The research key point was focused on the mechanism of volatiles from stink bugs and host plants including the basis of biology, population dynamics and spatial distribution.By using gas chromatography-mass (GC-MS), four common compounds from ether extracts of adult MTG, (E)-2-octenal, undecane, dodecane and tridecane, were monitored. Fifteen components isolated and identified from the extracts of adult bodies were undecane, dodecane, tridecane,1-tridecene, etc. Tridecane was a common component of females and males at a high level. n-Hexane extracts from excrement of adult females were (E)-2-hexen-l-ol acetate, dodecane and tridecane, while only tridecane was examed in excrement from males. The volatiles produced by either adults and nymphs or nymphs disturbed were identified by solid phase microextraction (SPME) combined with GC-MS. The richest components of adult bodies were dodecane, tridecane, pentadecane,2-heptanone. 1-tridecene, etc. Tridecane was the highest in both females and males, reaching up to 91.70% and 85.10%, respectively. The volatile compounds produced by nymph bodies and nymphs disturbed contained (E)-2-octenal, (E)-2-decenal, dodecane, tridecane,1-tridecene, etc., other compounds found in nymphs disturbed were (E)-2-hexenal, (E)-2-octen-l-ol, undecane, nonenal, pentadecane, tetradecane, n-heptadecane, etc.Litchi chinensis is a tropical fruit native to China. Its volatile compounds were extracted using simultaneous distillation extraction (SDE). GC-MS analysis of the volatile extracts identified as many as 20 components existing in the various volatile fractions (mechanical damaged functional leaves, mechanical damaged young leaves, healthy and intact functional leaves, healthy and intact young leaves), including three aldehydes,13 terpenoids, one acid, two alcohols and one ester. Terpenoids were the major components of volatile blends. The other major compounds included zingiberene (38.60-66.30 %),trans-caryophyllene (12.20-33.40%),α-sesquiphellandrene (7.22-13.60%),α-humulene (2.24-4.06%).α-bergamotene (0.97-1.32%) andα-copaene (0.69-1.02%). Different treatments resulted in volatile extracts with different proportions of the major volatile components. Hexanal, sabinene, (E)-2-hexenal, (E)-2-heptenal, veridiflorol,δ-cadinene and n-hexadecanoic acid were found in the functional leaves, whileδ-elemene and L-linalool were only detected in the young leaves. Furthermore, the mechanical damaged leaves contained a relative more a-copaene, a-bergamotene, a-sesquiphellandrene and trans-caryophyllene compared to the healthy and intact leaves. Relatively low concentrations of valencene and trans-α-farnesene were only induced by the mechanical damage of the plant material during SDE process.Further, preliminary results of petri dish bioassay showed that n-hexane and ether extracts of bodies of female and male T. papillosa were obviously attractive to the opposite sex and the same sex, respectively. Electroantennogram (EAG) results also demonstrated that both two kinds of solvent extracts could induce the EAG responses of adult T. papillosa. The ether extracts from metathoracic gland (MTG) secretions of adult T. papillosa were repellent to adult T. papillosa themselves. The results of Y-tube olfactometer bioassay showed that volatiles from bodies of adults were repellent to both 2 nd instar nymphs and females, volatiles from bodies of females were attractive to 3 rd instar nymphs and repellent to 5 th instar nymphs. The secretions from MTG of adult females were attractive to 2 nd instar nymphs and males while that of adult males were repellent to males. In EAG assays, among antenna of 5 th instar nymphs showed the highest sensitivity to MTG secretions from adults, and the EAG responses of 1 st instar nymphs and males to MTG secretions from males were strong while the antenna of males showed the low sensitivity to MTG secretions from females.Thirteen volatile compounds from T. papillosa, (E)-2-hexenal, (E)-2-octenal, nonenal, (E)-2-decenal,2-heptatone, (E)-2-octen-1-ol,1-tridecene, n-heptadecane, undecane, dodecane, tridecane, tetradecane and pentadecane, and 6 volatiles from L. chinensis, hexanal. (E)-2-heptenal, (Z)-3-hexen-1-ol, (Z)-3-hexenyl acetate, trans-caryophyllene, were choiced to apply to the experiments on the responses of stink bugs to these compounds and different concentrations. The results showed that (E)-2-octenal and (E)-2-decenal were obviously repellent to adults, and in which EAG value of female antenna to (E)-2-decenal was the highest. (E)-2-Octenal, n-heptadecane, trans-caryophyllene and (E)-2-decenal were repellent to nymphs while hexanal elicited the strongest EAG values of nymph antenna. The long-chain alkane n-heptadecane was attractive to both 1 st instar nymphs and adult males. With the different concentrations of the volatiles, (E)-2-octenal (100μL/μL), (E)-2-decenal (100μL/μL), (Z)-3-hexenyl acetate (0.01μL/μL) and pentadecane (1μL/μL) were repellent to the females and males which were attracted by hexanal (0.1μL/μL) and 1-tridecene (0.1μL/μL). The choice percentages of females to (E)-2-heptenal (0.1μL/μL) and males to (E)-2-octenal (0.01μL/μL) were the highest. The repellent effect of 2-heptatone (0.01μL/μL) to females and (E)-2-decenal (100μL/μL) to males was the most obvious. The results also demonstrated that 1 st instar nymphs were obviously repelled by n-heptadecane (1μL/μL), and 5 th instar nymphs were obviously attracted by 2-heptanone (0.1μL/μL).It is noted that the volatile compounds from the stink bugs and their host plant played an important role. We identified behavioral differences on volatile chemicals to the stink bugs, the results could provide more useful information and theoretical support on the mechanism of controlling pests and monitoring the populations of the stink bugs in the field.
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