| Ten typical tea gardens with environment and cultivation characteristics,i.e.tea garden among mountain forest,half-natural condition tea garden,common fertility tea garden,high efficient fertility tea garden,national tea plant idioplasm resource garden,tea garden around village,tea garden beside forests and brooks,tour tea garden in resort,tea and forest intercrop tea garden,and tea garden on hillside,were chose as the experimental tea gardens.From September of 2007 to December of 2008,the population density of tea geometrids and Apanteles spp.were surveyed.Through the statistical analysis,the following results had been acquired:①Among ten types of tea gardens,the population of tea geometrid or the population of Apanteles spp.in tea garden on hillside was the largest;however,the ratio of Apanteles spp.to tea geometrid population was less,and the population of Apanteles spp.was as 0.1578 times as the population of tea geometrid.Apanteles spp.could not control tea geometrid effectively.The population density of tea geometrid in common fertility tea garden,high efficient fertility tea garden and tour tea garden in resort were larger,and the population density of Apanteles spp.less,too.And the population of Apanteles spp.was as 0.1720,0.1738 and 0.6441 times as that of tea geometrid,respectively.Apanteles spp.could not suppress tea geomrtrid availably.The population of Apanteles spp.was as 2.8939, 2.4800,1.6250,3.0882,7.3333 and 1.1769 times as that of tea geometrid in tea garden among mountain forest,half-natural condition tea garden,national tea plant idioplasm resource garden,tea garden around village,tea garden beside forests and brooks,tea and forest intercrop tea garden,in turn.In the latter six types of tea gardens tea geometrids did not damaded tea plants badly.As a whole,in each tea garden the population of Apanteles spp.followed the population of tea geometrid obviously.②Among ten types of tea gardens,the difference in the population density from the lower layer of tea clump was the largest,and the difference in the population density from the upper layer of tea clump was the least.Tea geometrids aggregated in the lower layer of tea clump,with minor population in the upper layer of tea clump.The difference in the population density of Apanteles spp.from the middle layer of tea clump was the largest,and the difference in the population density from the upper layer of tea clump was the least.Apanteles spp.aggregated in the upper and middle layers of tea clump,especially the middle layer,with minor population in the lower layer of tea clump.③Among ten types of tea gardens,the difference in population of tea geometrid within upper,middle and lower layer from the tour tea garden in resort was the largest, with the largest population of tea geometrid in the lower layer,the intermediate population in the middle layer,and the minor population in the upper layer.The difference was the next in high efficient fertility tea garden and tea and forest intercrop tea garden.The difference in the other tea gardens was not significant,which meant the vertical distribution of population of tea geometrid were even relatively.As for the difference in the population of Apanteles spp.in the upper,middle and lower layer,the difference was the largest in tea garden among mountain forest and half-natural condition tea garden.The difference was the intermediate in the high efficient fertility tea garden,tour tea garden in resort and tea and forest intercrop tea garden.The difference was not significant in common fertility tea garden,national tea plant idioplasm resource garden,tea garden around village,tea garden beside forests and brooks and tea garden on hillside,,which meant the vertical distribution of population of Apanteles spp. were even relatively.④Environment and cultivation measures affected the population of tea geometrid and the population of Apanteles spp.In the tea garden with excellent environment conditions, complex ecosystem and great biodiversity,the population density of tea geometrid was low and that of Apanteles spp.was high.The natural regulation potential of tea garden to tea geometrid and Apanteles spp.is strong,which makes both in ecological equilibrium state.Through the analysis it is consided that more insecticides have been applied in common fertility tea garden and high efficient fertility tea garden,and long-term usage of pesticides broke the the ecological equilibrium in tea garden.Usually,the population of tea geometrid increases suddenly.The population density of Apanteles spp.is low.We think that agricultural,biological and other non-chemical measures should be applied as possible, so as to decrease and avoid the application of chemical insecticides,to mediate the population density of pests,to enhance biodiversity,and to realize the ecological equilibrium in tea garden system.Antennal-electrophysiological experiments of Apanteles sp.have been executed. Twenty-seven volatile compounds from the intact and tea geometrid larvae-damaged tea shoots,dissolved liquid paraffin at three dosages of 10-2 g/ml,10-4g/ml and 10-6g/ml, served as the tested odors,which were used in the detection of antennal-electrophysiological responses of Apanteles sp.that was the important natural enemy in the larval stage of tea geometrid.The results showed that:①on account of the category of the compounds,the fatty acid derivatives elicited the stronger EAG responses, the next were the aromatics and isothiocyanate,and the third were the sesquiterpenes and the monoterpenes.E-2-pentenal,Z-3-hexenyl acetate,phenethyl alcohol,E-2-hexenal, benzyl alcohol and acetophenone elicited the larger EAG response values,while 1-penten-3-ol,2-penten-1-ol,Z-3-hexen-1-ol,geraniol,ocimene,α- terpinen,(+)-cedrol, (+)-3-caren,α-humulen,Z-Jasmone andβ-lonone elicited the less EAG values;②from low to high dosage,the odors elicited EAG values with very great difference,and the dosage 10-2g/ml elicited the very large EAG values;③being based upon the analysis of chemical structure,the aldehydes elicited the stronger EAG responses,but the alcohols elicited the weaker EAG responses;④through the combination,E-2-hexenal, Z-3-hexen-1-ol and linalool composed blend 1,which elicited the largest EAG value,the next was Z-3-hexenyl acetate,and the third was E-2-pentenal.It was discussed that how to form a blend with the strong active by means of the combination of infochemicals,so as to achieve the much more stronger attracting activity to the parasitic wasp,and guide the parasitic wasp to lay egg into larvae of tea geometrids effectually.
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