Abstract: On Changxing island of Shanghai, whitefly occurs yearly three generations, with the 4th instar nymph overwintering there. In each stage, the death rate of eggs and 4th instar nymph is highest, and that of 2nd instar nymph is lowest. The survival curve of population is subjected to the weibull model type Ⅲ. The field population dynamics characterised by age structure reflects the growth and decline of whitefly in field and the effect of pesticide on them. The population dynamics of citrus whitefly on privet tree is analysed as well, and the roles of citrus whitefly served as alternate foods ofpredacity mite (Amblyseius eharai) are also discussed.

Key words: Citrus whitefly, Life cycle, Life table, Survival curve, Alternate food