Study On Community Structure Of Arthropod And Population Dynamics Of Main Pests In Urban Greenland

As an important part of ecosystem, urban greenland is a place for public amusement rests and exercises, It is also playing an important role in improvement of ecological environment. There are some reasons for pests seriously occurring, Such as unreasonable landscape designing and the bad protective measure. At the same time, the pests occur in the greenland not only make huge economy losses, but also destroy the beauty of the garden landscape. In order to research the community structure of arthropod and the influence of main pests in different urban greenland, different plots are selected in four types of greenland, Including different management level, land standing and public action. Using several methods to collect arthropod systematically in different plots, The structure of arthropod community and the population dynamics of main pests in diverse urban greenland is studied from April to October in 2006. The results are as follows:1 During the investigation in urban greenland, 56781 individuals belong to 14 orders, 69 families and 185 species are collected, there are 12 orders, 65families and 181 species in Insecta; 6835 individuals belong to 1 families and 1 species in Acarina; 197 individuals belong to 3 families and 3 species in Aranea. Among them, 49596 of pests are collected, which belong to 8 orders 38 families and 108 species, and main pests are Hyalopterus amygdali, Aphis citricola vander Goot, Periphyllus Koelreuteria, Tinocallis kahawaluokalani, Erythroneura sudra, Tetranychus viennensis Zacher etc; 2994 of natural enemies are ingathered, which belong to 9 orders 18 families and 28 species, Such as Chrysopidae, Coccinellidae and Ichneumonoidae. The species are distributed more equably in the natural enemy sub-communities than in the pest sub-communities, and so the pests occur easily in the pest sub-communities.2 The individual number of arthropod in different urban greenland: Jingxiu Park＞Shore Park＞Arboretum＞Military school square; the species of arthropod: Arboretum＞Military school square＞Shore Park＞Jingxiu Park. Thysanoptera is only discovered in the Military school square and Mecoptera is only discovered in the Shore Park. The arthropod of Homoptera occurr seriously in four parks, the individual amount of Homoptera account for 2/3, there is only a Acarina species discovered, but the individual amount is only inferrior to Homoptera pests. The diversity evenness and stability of arthropod communities and sub-communities: Arboretum＞Military school square＞Shore Park＞Jingxiu Park, The index of concentrator is contrast to diversity and evenness. The stability of arthropod community is stronger in Arboretum and worse in Jingxiu Park, Because people act more frequently in Jingxiu Park than in Arboretum.3 The total variational current of species amount and individual amount of arthropod in urban greenland from April to October: less→more→less again, the species is most in July, and the individual amount is the largest in May, but the individual amount is relatively less in July and August, which has a relation with the increasing number of natural enemies. The maximum of individual number of arthropod community appears in different month and plot: May in Arboretum and Shore Park, June in Jingxiu Park and July in Military school square.4 The research of arthropod community on different lawns indicated: The stability of Trifolium repens L. is higher than mixed lawns: F. arundinacea Sclrreb,Lolium perenne L. and Poa pratensis L. The research of different frutexes and arbors arthropod community indicated: it has higher diversity and evenness to configure many different plants together than configure arthropod community singly. Different plants configured together, which species are abundance and the community stability is strong. Meanwhile, the pests are not easy to happen and the configuration of garden sight is better.5 The result from the effect of different distance from sewage source to park on arthropod community: the more near to sewage source, the more individual amount of Diptera is. Therefore, the concentrator is higher, the species is less, and the diversity and the evenness is lower.6 The population dynamics of main pests and natural enemies researched: aphid and Didesmococcus koreanus have the largest harm in April and May; Tetranychusw viennensis Zacher, Acizzia jamatonica and Lithocolletis pastorella disserve seriously in June; leafhopper, Eriococcus lagerostroemiae, Trigonotylus ruficonis and Stephanitis nashi are happening greatly in July and August. There are most Chrysopa septempunctata in July and August, and most ladybugs from May to July.7 The time niche research of main pests and natural enemies indicated: In the four parks, the time niche of stick suction insect is most breadth, the results show that the harm of stick suction insect is most serious; the time niche of borer is narrowest, Because it centrally occurs in summer. By the research of time niche breadth and overlap, the results show that the niche of stick suction insect and predacious natural enemy overlapp: Arboretum＞Military school square＞Shore Park＞Jingxiu Park, which indicate the ability of Arboretum natural enemies to control the pests are the strongest and can cut down the pests species amount effectively.