The Dynamics And Control Evaluation Of Pest-Natural With The Relations Of Arthropod Community In Jujube Orchards Intercropping With Cotton

The survey collected92689, arthropod individuals in14sampling dates during the growingseason from the jujube-cotton intercropping system, belonging to70families,13orders, and3classes.Based on trophic relationships, arthropods were grouped into phytophagous, predacious andparasitic-neutral subcommunities. Relative abundances of the phytophagous community weregreater than those of the other subcommunities, being dominnat in the arthropod community andexercising major effects on the jujube-cotton intercropping ecosystem.Due to complicated interactions among pests, natural enemies, artifical agronomic practices,and natural factors, arthropod community in the jujube-cotton intercropping ecosytem flunctuatedtemporally in biodiversity indices. Gall midges (Cecidomyiidae) and spider mites (Tetranychidae)were dominant groups in the arthropod community, influencing community structure. Predaciousspecies were relatively abundant, and evenly distributed, dominated by Cocinellidae (e.g.Oenopiaconglobata, Stethorus punctillum), Chrysopidae and spiders. Individual distribution was relativelyeven in the parasitic-neutral subcommunity.Principal component analysis of7diveristy indices for arthropod communities showed thatthe second component of the total community and subcommunities contributed by86.6%、85.79%、88.32%、80.84%.The results revealed diversity H′、species S、Pielou evenness J andnumbers N concentration were synthetic indexes of community construction.The analyses revealed principal direct effects of the dominant concentration C on diversityindex H′of total community dominance D on diversity index H′of phytophagous and predatorssubcommunit, and evenness J on diversity index H′of the parasites-neutral subcommunity.Using Euclidean shortest distance to cluster total community and its subcommunities, weobtained four categories from total community by clustering distance D=1.76, from thephytophagous subcommunities by clustering distance D=2.2, five categories from the naturalenemy subcommunity by clustering distance D=1.62, and four categories from theparasitic-neutral subcommunity by clustering distance D=2.05. When taking seasonal periods intoconsideration, we obtained optimal divisions into7,4,5,and5stages for total, phytophagous,predators, and neutral-parasitoid subcommunity, respectively.The survey results suggest limited control of pests by natural enemies. The field trial resultsshowed that:(1)40%chlorpyrifos EC had quick and sustaining control effects;(2)3.5% imidacloprid WP and20%acetamiprid WP and5%bata-cyfluthrin EC had obvious effects byalternative application ongall midges;(3)Pyridaben mineral oil,20%Azocyclotin,3%avermectinand clofentezine diafenthiuron exercized trong effects on spider mitesby mixing or alternativeapplications.