Comparison of two methods of application of the organic acaricide Bienenwohl® in the control of Varroa destructor Anderson and Trueman

Abstract

Detection of chemical residues in honey has increased the demand for organic products to control the presence of the mite Varroa destructor, such as Bienenwohl. The aim of the study was to evaluate the effectiveness of Bienenwohl to control Varroa, with two application methods (direct application or mixed with soybean flour) and two doses (24 or 48 mL per hive). For the direct application method, one quarter of the total dose was applied on four different spraying dates six days apart. When the product was mixed with soybean flour, the total dose was applied once. The direct application treatment, at both doses, increased mite falling, reduced the infestation level and showed a higher efficacy than the mixed treatment. Compared to control hives, Bienenwohl induced 92 and 96% of mortality for 24 and 48 mL, respectively, while the same product mixed with soybean flour reduced the mites by 20 and 31% compared to the control, for the lower and higher doses, respectively.