The rate of population growth is one reason that the sweet potato whitefly
has become such a noxious pest. The effectiveness of an insecticide depends on
the methods, the rate and the frequency of application. It is apparent that the degree
of effectiveness of insecticides in the field correlate with the resistance status of
Bemisia tabaci. Resistance to Organophosphorous , carbamates and pyrethroids is
well established and involves a suit of mechanisms. In recent years, the need for a
greater diversity of different groups or classes of insecticides for whitefly control
having different mode of action become a must. Bioassays of whitefly field strains by
leaf dip were performed with the susceptible strain as well. Determination of the
eifectiveness of 20 insecticides typical of three foregoing year belonging to 7 classes
revealed that Insect Growth Regulators were in the first potency arrangement,
carbamate derivatives still effective and imidacloprid come up to the development of
resistance. In addition to all insecticides resistance levels tend to arise than before,
fenitrothion, chlorpyrifos-methyl and pirimiphos-methyl supposed to be neglect from
the future control.