Resistance of Tetranychus urticae Koch to Acaricides Used in the Greenhouse Production of Rosa in Mexico

In the State of Mexico, Mexico, Rosa sp. production is one of the most important economic activities. However, the two-spotted mite, Tetranychus urticae Koch, is a pest that limits this crop's productivity, and its control is carried out mainly with acaricides. Therefore, we estimated the levels of resistance to six acaricides in three field-collected populations of T. urticae from greenhouses of this growing region, and compared their response with a susceptible population of the same species. The products tested were abamectin, fenbutatin oxide, chlorfenapyr, amitraz, bifenthrin, and propargite. Significant differences were found in the response to the applied concentrations of acaricides. The levels of resistance were high to all tested acaricides, except fenbutatin oxide, in the Villa Guerrero and Tenancingo populations. The Coatepec population was susceptible to fenbutatin oxide and abamectin and had higher levels of tolerance to bifenthrin, amitraz, and chlorfenapyr. The RR50 values in resistant populations, ranged from 10 (propargite in Tenancingo population) to 6.400-fold (amitraz in Villa Guerrero population), in comparison to the susceptible reference. Amendments to both pest management strategies and the use of acaricides against T. urticae in Rosa sp. are proposed.