Clinical trial of the efficiency of three different compositions of acaricidal substances against varoosis in honey bee colonies

The aim of this study was to evaluate and compare the varroacidal efficacy and mite mortality dynamic during autumn treatment of honey bee colonies situated at two exper-imental areas, treated with three available authorized veterinary medicinal substances. In the autumn of 2017 clinical studies were conducted on the efficiency of the three acari-cidal combinations (AC) - one, based on 3. 6 mg flumethrin/strip (AC-1) and two contents essential oils (first one with composition: 5 g thymol and 2 g peppermint oil/plate (AC-2), and second one with composition: 4 g thymol and 2 g peppermint oil/plаte (AC-3). For control treatment we used the product containing coumaphos and additive with oxalic acid. After 35 days of flumethrin-strips exposure, an efficiency of 94.5% and 87.82% were achieved in the apiaries in Boychinovtsi and Zlatiya, respectively. The efficiencies of the other tested combinations - 5 g thymol/ and 2 g peppermint oil plate and 4 g thymol and 2 g peppermint oil /plate for 45 days were also high in the apiary in Zlatiya (AC-2 - 97% and for AC-3 - 95%) and in Boychinovtsi were 91% for AC-2 and 80% for AC-3, respectively. The results of the experiments showed the absence of resistance to the tested substances.