Studies On The Structure And Dynamics Of The Arthropod Communities In Bamboo Orchard In East Anhui

Based on the thorough investigation, the dynamics of the arthropod communities in bamboo orchard and interaction of the Hormaphididae with its natural enemies were studied by means of the community analysis, multi-analysis, grey system analysis and geostaistics for IPM of pests in bamboo orchard.1.The arthropod communities in bamboo orchard in east Anhui were divided into four sub-communities, which were Phytophages, predators, parasitoids and neutralities as to predator-prey relationship. The results indicated that there were 95 species of arthropod belonging to 72 families in bamboo orchard. The relative abundance of Phytophages was 0.9644, the value during April to December was 0.6028-0.9974; in December was highest, 0.9974. The relative abundance of predators was 0.0275, the value during April to December was 0.0025-0.3371; in December was lowest, 0.0025. The dominant concentration of arthropod communities was 0.3572; it showed that the dominant concentration of sub-communities was Phytophages>predators>parasitoids.2.The diversities and evenness of Phytophages sub-communities was in consistent with the total community; the tendency during April to December was from high to low, to high, and then, to low again. The diversity and evenness of predator sub-community was mainly steady, but occasionally ascended. By palb analysis of the relation between diversity index and other ecological index, which was evenness, richness, the number of species, individual, dominant concentration, dominance, the results indicated that the diversity of total community and Phytophages sub-community was mainly decided by evenness and the one of predators sub-community was connected with dominant concentration prominently.3.By analysis of clustering on every community, the results indicated that total community was divided 5 clusters, Phytophages sub-community 4, predators sub-community 3.The best temporal partitions in the arthropod total communities were 4.28－5.10, 5.28－6.11, 7.2－10.24, 11.24－12.29. The result of the best temporal partitions of Phytophages sub-community was the same as the total community. The result of the predators sub-community was 4.28－5.28, 6.11－7.21, 8.19－12.29.4.With the grey system theory and method, the relationship between Hormaphididae its natural enemies was analyzed. The results show that Taraka hamada Druce and Harmonia axyrides Pallas were the major natural enemy affecting Hormaphididae. The tendency of Taraka hamada Druce and Harmonia axyridis Pallas was the same as the number of Hormaphididae.5.The temporal niche breadth and overlap of Hormaphididae and its natural enemies, the vertical spatial breadth and overlap of them in different stage of bamboo growth were analyzed. Hormaphididae appeared in the stages of the new bamboo, but its population fluctuation showed two peaks, so that its niche breadth index was middle. But the temporal and vertical niche breadth of Taraka hamada Druce was higher; its niche overlap with Hormaphididae was also high. The niche breadth of Coccinellidae and spider natural enemies was fluctuated in different stage of bamboo. 6. Taraka hamada Druce on Hormaphididae were studied. The results were as follows: The predation act of starving Taraka hamada Druce for 12 to Hormaphididae was on 0-4 hours. Between 15 and 30 degree, the numbers of predation were ascended with soaring of degree. Between 30 and 35 degree the numbers of predation were descended with decline of degree. The more bamboo leaf the Taraka hamada Druce encountered, the more interference was met during the predation of Taraka hamada Druce, which means that the predation efficiency was low when the spatial heterogeneity was complex.7.Investigations on the spatial construction and distribution of Hormaphididae and its natural enemies, Taraka hamada Druce, 21 July, from 24 September to 29 December were conducted with geostatisticed. The results indicated the semivariogram of them could be described by spherical model, showing an aggregated spatial arrangement. The ranges of spatial depend...