First detection in Israel of fluvalinate resistance in the varroa mite using bioassay and biochemical methods

The aim of this study was to explore the extent of varroa mite resistance t o fluvalinate in Israel and to determine the underlying biochemical mechani sm. Assays at different apiaries indicated varroa mite resistance at three of the five sites tested. Dose response assays conducted with taufluvalinat e on mites obtained from different sites indicated uneven resistance. A mon ooxygenase assay revealed an increased rate (approximately 20-fold) of acti vity in mites that were not controlled by the pesticide, as compared to act ivity in mites from untreated colonies. A minor, 1.5-2.5 fold, increase of esterase activity was also noted in the resistant mites. This first demonst ration of a fluvalinate-resistance mechanism in varroa mites points to the need for more vigorous resistance management practices to control the pest.