Knowledge of the effects of pesticides on biological control agents is necessary for successful implementation of integrated pest management programs. The objective of this research was to evaluate the lethal effects of selected acaricides recommended for the control of European red mite, fenazaquin and spirodiclofen, on the development, survivorship and life-history parameters of Neoseiulus californicus as an important natural enemy of this pest mite under laboratory conditions. The acaricides tested significantly reduced the net fecundity/fertility of the predatory mite. The results indicated that adverse effects of the two treatments on population growth of N. californicus were significant. For fenazaquin, the intrinsic rate of increase (rm), net reproduction rate (R0), and finite rate of increase (λ) were reduced 1.70, 2.77 and 1.11 fold in comparison to the control treatment, respectively. These measures for spirodiclofen were 1.55, 2.61 and 1.09 in the same order. The intrinsic rate of increase (rm), net reproduction rate (R0), and finite rate of increase (λ) were significantly reduced in treated females compared to the control. The lethal effects of fenazaquin and spirodiclofen in conjunction with N. californicus to achieve efficient control of Panonychus ulmi management are discussed.
