Varroacidal efficacies of essential oils extracted from Lavandula officinalis, Foeniculum vulgare, and Laurus nobilis in naturally infested honeybee (Apis mellifera L.) colonies


Abstract: This study was performed to determine the efficacies of Lavandula officinalis, Foeniculum vulgare, and Laurus nobilis essential oils on the control of Varroa destructor (Acari: Varroidae), the most common parasite of honeybees (Apis mellifera L.). Experimental colonies from the province of Bursa, Turkey, were divided into 5 homogeneous groups of 8 hives each. The 3 essential oils plus thymol (Thymovar®, an essential oil-based drug with known efficacy that was used for comparison) were applied to 1 group each and 1 group was left untreated as a control. Each group was treated during 3 seasons, 2 consecutive autumns and 1 spring. Efficacies of the essential oils were determined by the Henderson-Tilton formula and the significance between the oils was determined by Tukey's multiple comparison test. In the first autumn, the highest efficacy was detected in Thymovar (79.4%) followed by L. nobilis (76.7%), L. officinalis (76.4%), and F. vulgare (74.5%) essential oils. In spring, the efficacy rates were 83.8% in L. officinalis, 81.8% in Thymovar, 78.8% in F. vulgare, and 70.8% in L. nobilis. In the second autumn, the efficacy rates were 78.4% in Thymovar, 76.6% in L. officinalis, 71.9% in F. vulgare, and 65.2% in L. nobilis respectively. No abnormal deaths were seen in adult bees during the treatment period.

Keywords: Efficacy, essential oils, honeybee, Varroa destructor, Turkey

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