Bio-assay of Diver® for mealy-bug and its parasitoid, A. bambawalei, was carried out during 2010-2011 in the IPM Laboratory, Department of Agri. Entomology, University of Agriculture, Faisalabad. All the concentrations of Diver®, which were applied in laboratory conditions, were effective against mealy-bug. Diver® is the best mineral oil to control mealy-bug when compared to other synthetic pesticides. On the numerical basis of data, which were recorded on mortality basis, the highest concentration of Diver® was most effective against mealy-bug, followed by the other concentrations. All the concentrations of Diver® on the parasitoid of mealy-bug swerve less and their effects were increased day by day, e.g. in 3 days the effect was minimal and in 21 days the effect of mortality was at its maximum because the residual toxicity of Diver® was present for a long time.