| Bemisia tabaci(Gennadius)has been an important insect pest of economic crops of vegetable, horticulture,cotton et al. Great yield and economic loss were resulted in due to the serious outbreak of B.tabaci national wide in late 90's. B.tabaci was a great threaten factor to the sustainable development of agriculture. In this paper, study benefited to know outbreak mechanism and disaster regulation of B.tabaci. Biology and ecology of B.tabaci were studied in system.The major contents included the population dynamics of B.tabaci,effects of temperature and host on experimental population, forecasting and controling technique of B.tabaci in the field.The major result obtained were as follows.l.The host plant of B.tabaci in Jiangsu Province was investigated in system in this papaer.There were 110 species of plant which belonged to 33 families as hosts of B. tabaci,in which Cucurbitaceae,Cruciferea,Solanaceae ,Compositae and Laguminosae et al were the main families.In Yangzhou region.there were 44 species of vegetable plants which belonged to 8 families as hosts of B.tabaci.The occurrence degree of B.tabaci was divided into four different grades according to number of B.tabaci on host plants. There were 11 species of vegetable plants which belonged to the forth grade.Thepopulation dynamics of B:tabaci on eggplant, cucumber, pepper, tomato, cabbage were preliminarily investigated in Yangzhou region,Jiangsu Province.The results indicated that B.tabaci was an insect pest that outbroke in autumn,the population of B.tabaci started to development in middle and lately June,then outbreak period was from lately August to middle and lately October.There were significant differences among the population densities of B.tabaci on different hosts,the order of population density was tomato > eggplant > cucumber > cabbage > pepper. Distribution regulation ofB. (abaci was studied on different locations of plants at the same time.2.Effects of temperature on population of B.tabaci were studied in this paper. Development rates of B.tabaci were observed on cabbage at seven constant temperatures ranging from 17~34. The relationship between temperature and developmental rate of B.tabaci were fitted by Wang-Lan-Ding model. The results showed that B.tabaci could tolerate higher temperature ranging from 35.1~37.0 and tolerate lower temperature ranging from 11.6~13.1. The development threshold and thermal requirement for its development at different stages were estimated by thedirect optimum method. The development thresholds of egg,larva,pupa and generation were 12.32, 13.04, 11.75, 9.09癈 respectively. Thermal requirements of egg, larva, pupa and generation were 111.26, 91.46, 116.16, 454.81 day degree respectively. Experiment of adversity temperature on B.tabaci was made. The results showed that pupa could endurance cold-hardiness and h6t-hardiness, but 1st larva could not do.Experiment of simulating overwinter was made. The results indicated that pupa of B.tabaci could overwinter in two layers of plastic sheet or in sunshine green house,B.tabaci could injure vegetable of green house in early spring.3.The quddratic curve model for relationship between temperature and survivalrate or oviposition was fitted' by the experimental date for B.tabaci. The theoretical optimum temperature for the development of eggs, lst~3rd larva,pupa,preoviposition and whole generation were 25.680, 25.843,25.020,26.056 and 25.474 respectively. Relationship between population trend index(I) and temperature(t) could be descried by the quddratic equations: I=-0.3832t 20:'203t-230.55.The theoretical optimum temperature for the highest population trend index of B.tabaci was 26.361 4.Effect of different hosts on population outbreak of B.tabaci was researched in this paper.Life-tables of an experimental population of B.tabaci feeding on eightspecies of host plants(cabbage, tomato, eggplant, tabacco, cucumber, pepper, cucurbit\and brassica) at 28 were estimulated. The results indicated that B.tabaci had a powerful choice on host. Higher oviposition number...
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