Study On The Spider Community Structure And Dynamics In Tobacco Field Of South Anhui

Spiders are main natural enemy,contribution of biocontrolling insect pests by spiders to improve tobacco ecosystems in South Anhui.But on tobacco spider oocysts affect the quality of tobacco,for tobacco growth period in open field spider community and oocysts for reasonable control.There are few study on spider community and oocysts in the tobacco field.It is necessary to clarify the structural characteristics of the spider community in tobacco field in South Anhui,using the research method of community ecology analyze the dynamic changes of spider community and oocysts in South Anhui,which can lay a foundation for a sustainable and development of tobacco in South Anhui.The results are as follows:1.Species composition of spider community in tobacco fieldThe spider community in tobacco field is mainly composed of Weaving-web spiders(large web spiders and small web spiders)and Wandering-spiders.A total of 1636 individual spiders(44 species,13 families)were investigated in this experiment,including 1551 individual spiders(28 species,7 families),85 individual spiders(16 species,6 families),130 individual spiders(15 species,2 families),1421 individual spiders(13 species,5 families).The spider communities of netting type on tobacco leaves include Tetragnatha squamata,Tetragnatha praedonia,Hylyphantes graminicola,Ummeliata insecticeps,Ebrechtella tricuspidate,Phintella debilis and Synema globosum.The number of individual number reached a peak of 278 on May 21,the dominant concentration index reached 0.7190 on May5,and the diversity index and evenness index reached 1.8806 and 0.7332 on July 5.Above all the characteristic indexes,the individual number of Weaving-web spiders on tobacco leaf is large.2.Dynamic analysis of spider community in chemical control field and non chemical control fieldThrough the diversity analysis,principal component analysis and community similarity analysis of chemical control field and non chemical control tobacco fields,the individual number of spider communities in the two fields is significantly different,and the similarity of spider community reached 0.6363 in May.On June 11,the oocysts of non chemically controlled spider reached the peak,and on June 20,the oocysts of chemically controlled spider reached the peak.3.Analysis of dominant species and spiders oocysts dynamics of tobacco field spiderThe dominant species of tobacco field spider in southern Anhui are H.graminicola and U.insecticeps,The individual number of is H.graminicola more than U.insecticeps,the peak time on May 28 and May 21.The spider oocysts reached the peak value on June 20.During this period,the spider oocysts were distributed in an aggregated manner in the field.