| Based on systematical investigations of single rice cropping fields and indoor experiments from Mar. to Oct., 2002, in Yueyang, Hunan, by using ecological and bio-statistic principles and methods, effect of ecological regulation and management on rice pests was studied mainly in following 3 aspects: structure characteristics and dynamics of the pest-spider community in rice fields, the health and security of rice-based ecosystem.In the fallow period, 31 species of spiders, which were collected from the rice-based ecosystem, belonging to 9 families and 20 genera, have been found and identified. The dominant species were Pirata subpiraticus Boes.et Str., Pardosa pseudoannulata Boes. et Str., Clubiona corrugata Boes. et Str., and Marpissa magisterKarsch. Only Lycosidae was the dominant guild. Tryporyza incertulas and Chilo supperssa--lis were main insect pest groups in the rice field. In the rice growth period, there were 50 species, 21 genera and 9 families of spiders in the rice field under IPM(IPMF). The dominant species were Coleosoma octomaculata Boes. et Str., Ummeliata insecticeps Boes. et Str., Pirata subpiraticus Boes. et Str., Pardosa pseudoannulata Boes. et Str., and Erigonidium graminicolum Sundevall, the dominant guilds were Lycosidae, Linyphiidae, Tetragnathidae, and Theridiidae. There were 42 species, 20 genera and 9 families of spiders in the rice field under chemical control (CCF). The dominant species were Pirata subpiraticusBoes. et Str., PardosapseudoannulataBoes. et Str., Coleosoma octomaculata Boes. et Str., Ummeliata insecticeps Boes.et Str., Tetragnatha maxillosa Thorell, and Marpissa magister Karsch, the dominant guilds were Lycosidae, Tetragnathidae, and Linyphiidae. Delphacidae, Cnaphalocrocismedinalis, and Jassidae were main insect pest groups in two types of rice fields.In the rice growth period, species diversity of spider community in IPMF was mainly influenced in turn by dominant concentricity, species richness, individual number, and planthopper population. The main components of influencing diversity of spider community in CCF were dominant concentricity, species richness, and evenness. The controlling effect of spider guilds and climate factors on insect pests could be narrated as follows: The main components to influence different insect pests could be different, and that which influenced same insect pests could change in different habitats.It could make for spiders controlling insect pests that the fitting stability of relationship between them was kept. The stability of spider community could be embodied through various kinds of concrete characteristic stability. Coefficient of variability could measure quantificationally the concrete characteristic stability of spider community. If the population of spider guild was in-between, the Coefficient of variability of spider guild was greater than that of the spider guild whose population was more or less, but the stability inversely. Both complete periodicity changes and incomplete periodicity changes of spider community were found in the rice-based ecosystem, and high level changes, rupturing changes, and low level changes were included in the incomplete periodicity changes. As time went on, the index of similarity between the IPMF and the CCF appeared a tendency to drop generally, but the index of dissimilarity inversely.According to structure characteristics and dynamics of rice pest-spider community, the whole rice growth period could be divided into 5 stages: winter regulation, communityestablishment, selective interference, community re-establishment, and helping natural enemies moving. In different stages, measures were supposed to be adjusted accordingly.The effect of protecting natural enemies and controlling pests was analyzed synthetically. The diversity level of spider communities and soil animal communities in IPMF was higher than that in CCF. The populations of weed communities were less in IPMF. Especially, the dosage of insecticide in IPMF was only 34.8% of that in CCF, and the cost o...
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