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This article through field investigation and trial of transgenic cotton field arthropod community structure as well as pests, natural enemies Advantage population dynamics; functional groups, trophic level analysis of arthropod species and communities are characterized by functional groups, and analysis of spatial and temporal changes in the dynamic; Indoor studied predators in cotton field on cotton aphid Predation and predation equivalent of system; different pesticides on arthropod community structure. Obtained the following results: arthropods in cotton community structure and its dynamic 1.1 community species composition and various groups of the number of dynamic field system survey recorded a total of Cotton Field 35 species, 24 kinds of predatory enemies, neutral arthropods six kinds; according to species function and status of the surveyed 62 arthropod species divided into 14 functional groups, divided into seven groups according to the functional characteristics of the various functional groups of arthropods, trophic relationships of arthropods in cotton divided into base bit species in 3 trophic levels a bit species and top positions species. 1.2 communities mainly dominant species spatial pattern and dynamic Arthropod Community pests dominant species of aphid, whitefly, cotton spider mites, cotton mirid; the predatory enemies dominant species for the four-lit belly spider, Moire scoop The black spider insects, T-Pardosa Kusama, eight spots ball belly spider Hua Ji reduviid, the flowers stink bug, green-winged paederus is. Spatial pattern of arthropod pests of predators showed accumulation characteristics between individuals, the degree of aggregation changes with time status, the natural enemies of the spatial distribution pattern reflects the choice of different enemies on habitat conditions, is closely related to the choice of prey . Black spider in the proportion of the distribution of the different parts of cotton, four lighted belly spider, T-Pardosa Kusama, eight spots ball belly spider flower plant bug, the green winged paederus for the lower part of the gt; Central gt; upper, pink gt; lice, cotton bugs for the upper middle of gt; lower part the China Ji reduviid, for upper gt; lower part gt; Central, aphids June 20, the upper gt; lower part gt; Central after June 30, upper gt the lower part of the gt;; Central, cotton spider mites in the early greater than for the lower part of the upper, late fluctuations are greater than the central, the P. japonica July 10 upper gt; Central gt; lower part 7 After January 20, the lower part of the gt; upper gt; Central. 1.3 community and the main features of the index and its dynamic analysis in cotton throughout the growing period of arthropods in the number of constant fluctuations and the formation of two peaks before a peak is less than a peak. Communities in the total number of individuals in the the Cotton Seedling few more in the bud flowering and boll stage; higher than the middle of the cotton growing early and late. Pre lower community evenness in the growth and development of cotton, gradual increase in the mid-late and gradually decline; contrary to the trend of the concentration and uniformity. Species and the functional group diversity index units are highly correlated, a correlation coefficient of r = 0.9904. 1.4 community dynamics fuzzy clustering analysis fuzzy clustering results show that the cotton fields at different times arthropod community can be divided into three categories seedling to bud stage (May 11), bud flowering period (June 30 to 20), flowering and boll period (July 30 to August 29). Overall, the cotton field arthropod communities in the course of time is more stable. 2 predators in cotton field of cotton aphid prey equivalent system 2.1 ladybug cotton aphid predator functional indoor measured japonica, Harmonia axyridis and black lapel wool ladybug, different instars of the cotton aphid predator function, predation the amount increases with increasing age and Holling Ⅱ type functional response are the the same instars, or peers larvae prey amount of Harmonia axyridis gt; the P. japonica gt; a black lapel wool ladybug. Measured 2.2 lacewings cotton aphid predator function indoor Chrysopa sinica and green lacewing larvae, adult predator function the same instars, or peers larvae predation fodder greater than China lacewings, its reaction function are Holling Ⅱ type. 2.3 predator bugs, paederus the predator functional indoor spider on cotton aphid predator stink bug was measured, predation found the green winged paederus and spider on cotton aphid predator stink bug, Staphylinidae and spiders natural enemies of cotton aphid great potential predation larger role in the natural control of cotton aphid population. 2.4 predatory natural enemies of cotton aphid predation equivalent system based on the main predators in cotton aphid predator function test results, the calculation of the correction equivalent coefficient of each natural enemies at different developmental stages, the main predators in cotton aphid predator equivalent system. 3 common insecticides impact study the community structure of arthropods in cotton the 3.1 different pesticides on pest and their predators in the eight kinds of commonly used in cotton fields insecticides have a certain impact on the major pests and their predators, destroy methomyl, chlorpyrifos, piperidine wins, imidacloprid, gold good control of the cotton aphid fast-acting, the effect is significant, phoxim, beta-cypermethrin, followed by the worst love promise worms clear effect from insecticides killing natural enemies regard, phoxim, methomyl Wei, cypermethrin, Lorsban killing effect of predators, imidacloprid, gold good years and love Connaught insect cleared most small killing effect on natural enemies. The 3.2 different insecticides after application of the index of community characteristics, phoxim, cypermethrin, Lorsban the total number of individuals of the community the greatest impact; phoxim and Lorsban community richness biggest; Sim parathion, beta-cypermethrin and chlorpyrifos affect community evenness largest phoxim, cypermethrin, chlorpyrifos this community diversity; each treatment 15 days after application, basically arthropod community structure recovery, making the cotton field ecosystems stabilize.
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