Comparison of conventional and integrated programs for control of Tetranychus urticae (Acari: Tetranychidae).

The twospotted spider mite (TSSM), Tetranychus urticae Koch, is one of the main pests on strawberry crops in Brazil. TSSM can be difficult to control due to acaricide resistance. The objective of this work was to compare the effect of conventional and integrated strawberry production (ISP) systems on mite abundance and acaricide resistance. The control of TSSM in ISP was based on the release of Neoseiulus californicus (McGregor) or application of a selective acaricide (propargite), when TSSM monitoring indicated the timing for the release of predaceous mites (1-3 mites per leaflet on 30% leaflets) or chemical intervention (>10 mites per leaflet). Only acaricides (abamectin, fenpyroximate) were applied in the conventional system. Integrated control of TSSM were sufficient to maintain a significantly lower pest infestation level, resulting in a sixfold reduction in the frequency of acaricide applications, and consequently, a lower selection pressure for acaricide resistance. Strategies for the management of TSSM in strawberry fields are described and discussed.