| In this paper, adopting the several common use parameters and methods of systematic sort-average-clustering, author researched the insect community (including spider) in harmless control section, general and blank control sections during Nov, 2001 to Oct, 2002 in Shenzhen city. The results indicate:The insect community in Shenzhen city includes 18 orders (insecta: 16 orders, spider: 2 orders) and 369 species. The insecta includes 119 families and 348 species, and the spider includes 21 species. In the whole insect community, the pests that have been defined include 63 species, which hold the 17.07% of whole community. The natural enemies (including predacity and parasitical enemy) include 79 species, which hold the 21.41% of the whole community. The moderate insect includes 227 species, which hold the 61.52% of the whole community.The total quantity of pest in the three experimentation sections is 4935, and the sequence of quantity to the three sections is blank section(2213)>harmless section (1551)>general section(1171). The key pests are Olethreutes leucaspis Meyrick, Conopomorpha sinemis Bradley, Xyleborm fornicatus Eichhoff, Dasineura sp. , Aceria litchii (Kiefer), Thalassodes quadraria Guen e, Tessaratoma papillosa (Drury). The quantity of natural enemy in the three sections is: blank section(1167)>harmless section(827)>general section(515), and the main natural enemies are Chrysopa sinica Tjeder, ladybug, Bracon Fabricus and spider. The accumulative dominance index of each section exceeds 0.9000.The sequence of moderate insect quantity of the three sections is blank section(3169)> general section(2308)>harmless section (2302). Among the moderate insect community, the ants of the hymenoptera is more than any other insects as for the species and quantity. The ants' quantity is 2203, and whose dominance index is 0.2832. The quantity of the rove beetles of the coleoptera is 1619, and whose dominance index is 0.2081. The pyralids moths and outlet moths of the lepidoptera, the leafhoppers of the homoptera, the darking beetles of coleptera and blow flies of the diptera take the dominant place in moderate insect community. The rates of pest, natural enemy and moderate insect in harmless section are similar with those in blank section, and the rates of pest and natural enemy in harmless section are higher than those in general section.The insect community of lichee orchard can be divided into 4 nutrient classes, which is phytophagous insect, predacity, parasite and saprophagous. The insect community also can be divided into 7 guilds: underground pest, eating-leaf-flower-fruit pest, puncture and suck pest, bristletail, predacity, parasite andmoderate insect, and be divided into 32 groups, 41 dominance species and 10 key species. Some dominance species can be turned into key species under proper conditions.In the insect community of lichee orchard, the main dominant phytophagous insects are the Olethreutes leucaspis Meyrick, Thalassodes quadraria Guen6e, Conopomorpha sinensis Bradley, Tessaratoma papillosa (Drury), Aceria litchii (Kiefer), Dasineura sp. , Xylebonts fornicatus Eichhoff, Prodenia litvara Fabricius, Empoasca flavescens (Fab.). The dominant predacity enemies are Chilomenes quadriplaglata fSwartz), Stethorus spp.,Chrysopa sinica Tjeder and the spider.The Ooencyrtus sp. and Phanerotoma spp. take the prior place in the parasite enemy . The dominant saprophagous insect are the ants, rove beetles and Blattella germanica Linnaeus. The main lichee pests are accord with the physiological growth period of lichee.The research result of insect community development indicate: the differences to quantity and richness of pest, natural enemy and whole insect community among experiment sections are distinct. The dynamic uptrend of diversity and evenness indexes between harmless section and general section are analogical, but that of blank section and two manage sections is different. Besides the richness of pest in harmless section is lower than that in blank section during fastigium, the quantit...
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