Studies On The Dynamics Of Arthropod Communities And Relations Between Dominant Pest And Its Natural Enemy In Grapery

Based on the thorough investigation, the dynamics of the arthropod communities in grapery and interaction of main insects with its natural enemies were studied by means of community analysis, grey system theory, path analysis and geostastics. These provided theory foundation for IPM. 1 T-test of the arthropod community in two different graperies.The result showed that only species and species abundance have significance.others diversity index of arthropod community have no significance. Variance analysis of different graperies,The result showed that the species between the control field and no control field have significance with net research,the numbers were no significance in dynamics of arthropod communities. 2 The arthropod community was divided into three sub-communities, which were phytophages, predators, parasitoids and neutralities. The results were showed 62 species of arthropod belonging to 59 families and 36 species of phytophages belonging to 34 families 23 species of predators belonging to 22 families in grapery. The relative abundance of phytophages was 0.47117. Halticinae.chalybca (Illiger) and Aphididae were dominant insects of phytophages. The relative abundance of predators was 0.44234. Micryphantidae Coccinellidae Pristomyrmex pungens Mayr and spiders were dominant enemies of predators. Dominance and dominant concentration of total communities were 0.127 and 0.092 respectively. Dominance of every sub-community showed phytophages>Parasitic and neutrality >predators. and dominant concentration of every sub-community showed Parasitic and neutrality>phytophages>predators. 3 The seasonal dynamics of sub-communities was in consistent with the total community; the tendency was from high to low, to high again. Hill diversity index was in relation to species, individuals, dominance, dominant concentration, Pielou evenness and species richness. Hill diversity index was most relative with dominant concentration(-0.9499),dominance(-0.9037),Pielou evenness(0.8840) by path analysis. Principal components analysis coordinates analyzed indexes of communities; the results revealed diversity, evenness, species richness and dominant concentration were synthetic indexes of community construction. 4 Diversity indexes of arthropod communities were analyzed by clustering and optimization partitions.D=1.64 Total community were divided into four stages.When phytophages(D=1.86) and predators(D=1.95) sub-communities were divided into four stages. The optimization partitions in the arthropod total communities were 2004.4.11~4.25 5.12~6.21,7.11 and 7.24~10.15.The result of the optimization partitions of phytophages sub-community was 4.11~5.22,5.31~6.12,6.21~7.11 and 7.24~10.15. The result of the optimization partitions of predators sub-community was 4.11~5.12,5.22~7.11,7.24~9.12 and 10.15. 5 Study on the relationship of Halticinae.chalybca (Illiger) and its natural enemies by grey theory, the result showed Erigonidium graminicolum and Tetragnathidae were its ideal dominant enemies and Thomisidae, Lycosidae and Syrphidae were main enemies. 6 Study on spatial construction and relationship of Halticinae.chalybca (Illiger)and Erigonidium graminicolum by geostastics from May to August, spatial construction of Halticinae.chalybca (Illiger) and Erigonidium graminicolum showed aggregated distribution at different periods and its semi-variance models were spherical. The ranges of spatial dependence of Halticinae.chalybca (Illiger) and Erigonidium graminicolum were 1.164~8.508 and 2.977~7.799 respectively. The value of spatial dependence was near at different period . These results showed Erigonidium graminicolum followed with Halticinae.chalybca (Illiger) on populations and space. Therefore, Erigonidium graminicolum was dominant natural enemy of Halticinae.chalybca (Illiger).