| With the increase of introduced plants and greening area and the sharp changing of the patterns of urban virescence, important pests break out frequently in some greenbelts and severely damage the garden plants, resulting in bad effect on urban gardens landscaping. In order to provide scientific basis of implementing integrated pest management, the pest species on urban garden plants were investigated systematically from 2004 to 2007 in Yangzhou and the spatial pattern of several important pests and the temporal dynamics of phototactic insects community were studied. At the same time, the biology and ecology of Orthaga achatina Butler were also studied. The main results were as follows.1. The pest species on 85 kinds of important garden plants were investigated in the greenbelts of Shouxihu beauty spot, Zhuyuwan Park, Ge Park and urban streets in Yangzhou from the year 2004 to 2007. The gardens pests in Yangzhou were found to have 400 species, 97 families, 12 orders in 3 classes.2. Jiaduo forecast lamp was used to monitor phototactic pests in urban garden greenbelts. The gardens pests in Yangzhou were found to have 345 species, 68 families, 12 orders in one class. Among them, 280 species were pests, 23 species were neutral insects and 42 species were natural enemies. Characteristic parameters of insect community were uesd to analyze the temporal dynamics of phototactic insects community by fuzzy cluster method. The results showed that total community could be clustered into 6 clusters (D=0.40); phototactic pest and natural enemy sub-community could be clustered into 5 clusters (D=0.30); phototactic netural insect sub-community could be clustered into 4 clusters (D=0.58). In addition, by the method of optimum partitionting and principal component analysis, the communities could be cut into 4 phases, demonstrating the differences of the species and quantity in different phases. This reflected the seasonality of phototactic insect community.3. We studied the sptial patterns of Didesmococcus korcanus Borchsenius, Argopistes tsekooni Chen and Euricania clara Kato in Yangzhou urban garden greenbelts. The results showed that they were all in aggregative distribution in nature. At the same time, spatial distribution parameters were used to found the corresponding academic sampling and sequential sampling model, and compound sequential sampling model was constructed by combining with other different sampling models in order to provide an academic basis for scientific sampling, pest prediction and control measures..4. The biological characteristics of Orthaga achatina Butler were investigated outdoors and the results showed that it has 2 generations a year in Yangzhou, that it overwinters with the last instar larvae in shallow horizon of soil and the adult emerges in june the next year, that the peak of damaging is from August to October. Different temperature were designed to examine their effects on the development, livability and procreation of O. achatina, and the life tables of its laboratory population were constructed. The results showed the optimum temperature of O. achatina was 25℃～28℃, and the relationship between developmental rate and temperature accorded with the logistic model under appropriate temperature . Under 25℃temperature the livability of O. achatina larvae reached 100% and the fecundity of a female was 42.5 averagely. The correlativity analysis of population trend index with laboratorial temperature showed that the highest population trend index was 3.69 when the temperature was 25.37℃. The egg hatching rate was 37.6% under 19℃and the survival rate of larva was 24.21% under 31℃. These demonstrated that high or low temperature had a great influence on the survival rate of each generation.
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