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 to fluvalinate in Israel and to determine the underlying biochemical mechanism. Assays at different apiaries indicated varroa mite resistance at three of the five sites tested. Dose response assays conducted with tau-fluvalinate on mites obtained from different sites indicated uneven resistance. A monooxygenase assay revealed an increased rate (approximately 20-fold) of activity in mites that were not controlled by the pesticide, as compared to activity 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 demonstration of a fluvalinate-resistance mechanism in varroa mites points to the need for more vigorous resistance management practices to control the pest.