Abstract:

In order to explore the biological characteristics and population dynamics of whitefly (Bemisia tabaci) in growing vegetables in the suburbs, and improve monitoring and control techniques, using rearing and trapping adult whitefly (Bemisia tabaci) with oil painting yellow plastic plates during 2005-2010, the results showed that: whitefly can occur 11 generations in Linhai area of mid-Zhejiang Province and generations overlap seriously, the formation of began to gradual increase in June and rapid increase after July, and peaked from August to September, and fall as temperatures after mid-October in population by rearing indoor, and by monitoring outdoor the formation of adults can occur a year in greenhouse ,and can be to the overwinter of 20% in the open, its overwinter critical temperature is 8-8.5℃ (60 days average temperature from mid-December to mid-February next year) . Annual population dynamics of whitefly can be described by bimodal curve, and the peak times is synchronization between in the open and greenhouse, the summer peak usually appears during mid-May and early September, and the autumn peak usually comes between mid-October and late November. There are three main factors effecting whitefly population: base population, climate, farming system and flood inundation. The most important factor is temperature，the whitefly population density (M)is changing with temperature (T℃), the linear relationship can be described by model: M=0.607T-4.0645, n=36; r=0.6826**, and the curve model is M = 0.0071T2+0.3513T-2.2188, n=36; r=0.6846**. When 10 days average temperature between 8-10℃, the whitefly population is in survival critical situation；and 10 days average temperature between 10-20℃, the population density will keep small, when 10 days average temperature above 20℃, the population will increase very fast with the increasing of temperature, but 10 days average temperature keeps above 30℃, the whitefly population will decrease to a comparative bust. Afterword, the population will increase to the peak again, and cause heavy damage of autumn vegetable production.