Mathematical Analysis Of The Relationship Between Pests And Natural Enemies In "Wuniuzao" And "Baihaozao" Tea Gardens

This project was originated from the National Natural Science Foundation of China(30871444)and Anhui Natural Science Foundation of China(11040606M71).A systematic investigation on arthropod communities in "Baihaozao" and "Wuniuzao" tea plantations in 2015 and 2016 in Hefei,Anhui Province.The survey data of two kinds of tea plantations were processed and analyzed by grey correlation degree analysis,geostatistics analysis,niche overlap analysis,block square variance analysis,fuzzy cluster analysis,population aggregation mean method and ? index method.The community structure and dynamic changes of pests and their main natural enemies in tea plantations were clarified,which can provide theoretical basis for the prevention and control of tea pests.The dominant species of pests and their natural enemies in tea gardens with different sizes of clumps were analyzed by block square variance analysis,grey correlation degree method,spatial aggregation intensity index,population aggregation mean number method and ? index method.The ? index of clumps of different sizes was used to judge the minimum range of aggregation of individual groups.It was found that the minimum range of Ricania speculum and Fulgoroidea was 4 basic quadrats in clumps and 1 basic quadrat for Empoasca vitis.Using geostatistical method to obtain the respective ranges of natural enemies and pests,and then using grey correlation degree method to analyze the quantitative correlation degree between natural enemies and pests and the correlation degree between natural enemies and the range of spatial semivariogram theoretical model of pests.The niche analysis method is used to study the temporal niche similarity coefficient between natural enemies and pests,and the above results are standardized,that is to say,the quotient of the two correlation degrees and similarity coefficients divided by the maximum value of this type of parameter is the close index.The largest sum of the closeness indexes is the first natural enemy closely related to pests.Based on this,the differences between tea varieties and years of natural enemies closely related to pests are analyzed.Investigation and research results show that the dominant species and dominant species of pests in the tea garden are the natural enemies,including Empooasca vitis Gothe,Ricania speculum Walker,Brevellus Obovatus Donadieu,and Caloptilia theivora Walsingham and so on are the main dominant species of tea garden pests.The first dominant natural enemy of Empoasca vitis Gothe is Neoscona theisi Walckenaer.Thefirst dominant natural enemy of Ricania speculum Walker is Erigonidium graminicolum Sundevall.The first dominant natural enemy of Brevellus Obovatus Donadieu is Tetragnatha squamata Karsch.The first dominant natural enemy of Caloptilia theivora Walsingham is Clubiona japonicola Boes.et Str.In order to give full play to the role of neutral insects and mosquitoes as bait substitutes for natural enemies and scientifically protect and utilize natural enemies,geostatistical methods are used to obtain the respective changes of natural enemies and mosquitoes.The grey correlation degree method is used to analyze the correlation degree between mosquitoes and natural enemies.The larger the correlation degree value is,the closer the natural enemies follow mosquitoes in space.Comprehensive evaluation shows that the top three natural enemies closely related to mosquito space in the two tea gardens of "Baihaozao" and "Wuniuzao" in March to May in 2015 and 2016 are Clubiona japonicola,Misumenops tricuspidatus,and Neoscona theisi respectively.This part of the results provide scientific basis for human to promote the formation of dominant species of natural enemies and to reasonably protect and utilize natural enemies.