A comparison of two methods of applying oxalic acid for control of varroa
Varroa destructor is a serious parasite of honey bees (Apis mellifera) throughout the world. At present, synthetic acaricides are used for the control of this mite. Acaricide-resistant mites and pesticide residues in honey and wax have appeared in many countries. These problems have led to the development of natural substances for control of varroa, such as different organic acids and essential oils. Among the organic acids, oxalic acid (OA) is registered in many countries. In this study, I compared two methods of applying OA dehydrate 3.5% - the spraying and trickling methods - for the control of V. destructor under the environmental conditions of Iran. Average mite mortality was 99.0, 95.1 and 6.8% for spraying, trickling, and control treatments, respectively. Mite mortality was not significantly different between spraying and trickling methods, but mortality was significantly higher between OA treatments and control (P < 0.05). During these trials no queens died and colonies behaved normally.