Response to Some Acaricides of the Two-spotted Spider Mite (Tetranychus urticae Koch) from Protected Vegetables in Isparta


Abstract: The two-spotted spider mite, Tetranychus urticae Koch, was tested for susceptibility to various acaricides, propargite (Omite) 570 g l^{-1}, amitraz (Kortraz) 200 g l^{-1} and abamectin (Agrimec) 18 g l^{-1}. Propargite, a selective acaricide, has been used to control T. urticae in many crops in Turkey. Amitraz and abamectin have acaricidal and insecticidal properties, and are thus used to control spider mites and some vegetable pests (e.g., whiteflies and Liriomyza spp.). Five different T. urticae populations collected from vegetable greenhouses in Isparta and their responses to those acaricides were investigated by leaf dip assay and compared with those of a susceptible reference strain. Resistance ratios for the chemicals ranged from <1.00 to 2.5 for propargite, 1.2 to 2.1 for amitraz and <1.0 to 2.9 for abamectin (based on LC_{50}). Since the greenhouses around Isparta province where the two-spotted spider mite populations were collected have recently been constructed, the populations used in this study were not exposed to excessive acaricides and had had no important loss of susceptibility to the acaricides applied in the study. However, it was observed that the growers used pesticides haphazardly.

Keywords: Tetranychus urticae, acaricide, bioassay, Propargite, Amitraz, Abamectin

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