Evaluation of a new plant-based formulation for the treatment of varroosis in the honey bee colonies: efficacy and safety

Research and development of new natural and safe veterinary medicaments to treat honey bee varroosis caused by Varroa destructor Anderson and Trueman is an important step on the path to embarking on organic beekeeping. In the present research, field experiments were conducted to evaluate the efficacy of a new plant-based formulation against varroa mite and its safety for the honey bees during the summer and autumn of 2018 in Shirvan, North Khorasan, Iran. It was found that the corrected efficacy of this formulation in the summer (48.70%) was significantly higher than that in the autumn (29.08%). These results proved the importance of ambient temperature on the varroacidal effectiveness of the formulation. An acceptable safety margin for eggs, larvae, adult workers, and queen bees was observed after employing the formulation over a 4-week treatment period in the summer experiment. The effects of the formulation on the enzyme activities and the amounts of energy reserves of the treated bees are also discussed.