The Community Structure Of Insect And Natural Enemies Control To Aphis In Soybean Fiel

In this article, we investigated the types and dynamics of all the lively insects in soybean fieldin Harbin region, in order to explicate the types and dynamics of the pests and natural enemyinsects in corresponding soybean field, promulgate the compositions and mutual restrictionrelations of pests and its natural enemies communities in soybean field ecosystem. The work wehad done may lay the rationale for using corresponding natural enemies to develop biologypreventing and controlling, and may have the certain instruction significance to the pest preventingand controlling work in the green agricultural production.We took the spot stochastically in the investigation of the experiment, inspected the volitantinsect types and dynamics of the soybean plants in soybean field, and to appraise the insect typescombining with direct observation method. We used the trap method to the ground roostsoccupying insects, adopted the opposite angle line five spots method to investigate.The main studying results of the test were as follows:1. Kinds of the insects in soybean fieldIn the field investigation of 2005 to 2006, we found that the sum of the volitant insects cameto 10 order, 37 family and 63 species. Among them, the sum of pest was 7 order, 20 family and 36species, the sum of natural enemies was 6 order, 12 family and 20 species and the natural enemieswere 6 order, 7 family and 7 species.2. The community characteristic indexWe analyzed the data of the community structure of the insects in the investigated field; wefound from it that, in 2005, the diversity index of the insect community in soybean field was high,the equiability was better and the advantage centrality index was less. That manifested that thecommunity structure of the insects in soybean field in 2005 was more stable, on the contrary, in2006, the diversity index of the insect community in soybean field was low, the equiability was notgood and the advantage centrality index was higher. That manifested that the community structureof the insects in soybean field in 2006 was not stable.3. The advantage insects in soybean fieldWe found the advantage insects vary from time to time in soybean field. The advantage insectswere: Lasius niger,Chlaenius praefectus,Craspedonotus tibiali,Aphis glycines,Aulacorthumsolani,Megalurothrips usitatus,Medythia nigrobilineata,Ascotis selenaria,Propylaea japonicaThunberg,Leis axyridis,Chrysopa phyllochroma Wesmael,Triphleps minutus.Among them themain advantage pests were Aphis glycines,Aulacorthum solani; the main advantage natural Thunberg,Leis axyridis,Chrysopa phyllochroma Wesmael,Triphleps minutus.Among them themain advantage pests were Aphis glycines, Aulacorthum solani; the main advantage naturalenemies were Propylaea japonica Thunberg,Leis axyridis,Chrysopa phyllochroma Wesmael,Triphleps minutus.4. The dynamics of species group in soybean fieldWe analyzed the data of 2005 and 2006, and got the population dynamics of every insect insoybean field. We may see the occurring, growth and decline rule of every insect, and the spacedistribution condition of every insect in soybean plants.5. The regulation and control facility of advantage natural enemies to aphisWe analyzed the data and found advantage natural enemies had certain controlling function toaphis. The controlling function time of every advantage nature enemies was different. Thequantities of advantage natural enemies varied from the quantities of aphis, and the peak value ofthe quantity of advantage natural enemies aphid population quantity also appeared front and backthe peak value of aphis population quantity. That explained that the advantage natural enemies hadcertain reality applied value in the field of the pest preventing and controlling.