Abstract: Investigations on the population fluctuation patterns of important arthropods on three Nicotiana tabacum production varieties Nc89, Nc82 and K326 were conducted in the suburbs of Hefei from May to July, 1998. In the investigated tobacco fields, araneae taxa were Linyphiidae, Lycosodae, Theriodiidae, Tetragnathidae, Thomisidae, Salticidae and Clubionidae, etc.. The major insect natural enemies were Aphidius gifuensis, Coccinellidae, Staphylinidae, Carabidae, Syrphas corallae and Orius miutus, and the major insect pests were Myzus persicae, Heliothis assulta, Dolycoris baccarum and Gryllus testaceus. The aphid population fluctuation showed two peaks, with the first one around 16 May and the second one from 13 to 21 June. The models of aphid population dynamics and the interreaction between Myzus persicae and Erigonidium graminicola were analysed. The mean seasonal number of Aphidius gifuensis population, and hence, that of total insect pests, were significantly higher on Nc89 than on Nc82 and K326. There was no significant difference in the mean seasonal number of other arthropods on different tobacco varieties.

Key words: Tobacco variety, Arthropod, Population dynamics, Michaelis constant, cadmium pollution, uptake rate, rice