| The olfactory response of Acantholyda posticalis to odor vlatiles from 7 species of trees(Pinus tabulaeformis, Pinus densiflora, Pinus armandi, Pinus thunbergii, Pinus bungeana, Cedrus deodara, Platycladus orientalis) were researched by using "Y"-shaped olfactomerer,wind tunnel and net cage,and the visusal selectivity of the insect to different colours and different shapes of green leaf blades also studied.The volatility substances from 5 species of host trees were extracted and analysed by means of SPME(Solid Phase Microextraction)and GC-MS(Gas Chromaogragh-Mass Spectrometer),using EAG(Electroantennogram),The result is following :1. The odor responses of adult Acantholyda Posticalis to different host volatiles "Y"-olfactomerer In the process of adult Acantholyda Posticalis searching host plants ,The reaction has a hand in in the scent ,that's,it can be attracted by the volatiles of host plants.Different hosts attribute their own degrees,and Actions of Pinus tabulaeformis and Pinus densiflora are best,at 66.3%. Certain species' actions to female and male Acantholyda Posticalis are different. The wind-tunnel Acantholyda Posticalis shows great tendency to host plants, especially Pinus tabulaeformis and Pinus densiflora, at 59.6%. During the process of serching, adult almost crawl to the hosts (5.3% of them is flying up windly), and it shows no tendency to no-host plants.The observation of net cage Acantholyda Posticalis shows great preference to hosts, such as Pinus tabulaeformis, Pinus densiflora,Pinus armandi, Pinus thunbergii, the rate of choices are 11.43%, 10.57%, 10.79% and 8.14%, respectively. It is on the contrary to no-host, including Cedrus deodara, Pinus bungeana, Platycladus orientalis, respectively, 5.07%, 4.22% and 3.36%. Male shows more siginificent choice to the combination of hosts and female than only hosts.The observation of forest field Pinus tabulaeformis and Pinus densiflora in forest field are destroyed seriously, but Pinus armandi near the forest is light .It shows that the former could be the most suitable host of the pest. 2.The tendency of Acantholyda Posticalis to the different colours The insect expressed very powerful tendency to the green,at 51.0%, To yellow ,The red is unobvious as the pink, respectively, 19.0%, 13.0% and 17.0%. 3. The tendency of Acantholyda Posticalis to the different shapes The insect shows tendency to the leaves of Pinus tabulaeformis at 30.0%, Platycladus orientalis, 19.8%; Quercus acutissima 18.0%; strip paper, 15.3%.4.GC-MS of the volatiles of different host according to the analysis of the volatiles of test plants1) They could take an important role in long distance choice ,includingα-pinene, β-pinene, caryophyllene, β- myrcene, limonene, terpeneA, α- caryophyllene, α- farensene.2) Four kinds of components could attract Acantholyda Posticalis by momomer or special ratio in the volatiles of host ,including L-α-bornyl acetate,NaphthaleneA,NaphthaleneB, decahydro-4,8,8-trimethyl-9-methylene-1,4-Methanoazulene.3) It is not the matters of attracting Acantholyda Posticalis, including 3-carene, phellandrene, thujopsene.5.EAG response to the volatiles of different host plants 1) The frequencies inducede by the volatiles of Pinus tabulaeformis, Pinus densiflora, Pinus armandi, Pinus thunbergii are 43.7 time/s, 40.9time/s, 39.4time/s and 42.9time/s, respectively ,but Platycladus orientalis 30.2 time/s, quitly different from the former.2) Host plants induced greater electricity values, such as Pinus tabulaeformis, Pinus densiflora, Pinus armandi, and at 1.040mV, 1.100mV and 0.690mV, respectively, but non-hosts, for example Cedrus deodara, Platycladus orientalis, 0.530mV and 0.419mV, respectively.3) The activity of EAG is in accord with the volatile current, the bigger the currents are, the higher the electricity values are.
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