Annual control of varroa mites is essential in order to prevent the withering away of infested colonies. To avoid problems with residues and resistance associated with the use of acaricides from the group of the pyrethroids (Apistan and Bayvarol) or the phosphoric acid esters (Perizin), the Swiss Bee Research Centre developed a so-called 'alternative' control method in cooperation with European partners. The method is based on the use of organic acids (formic and oxalic acids) and essential oils (thymol).

Our studies served as a basis for the development of a treatment concept that was incorporated into the current recommendations of the Bee Health Service.