Effectiveness of glycerin-oxalic acid strips and essential oils in controlling Varroa destructor in honeybee

The decline in the bee colony strength due to high levels of <i>Varroa destructor</i> infestations necessitates the development of new control methods. This study evaluates the effectiveness of glycerin-oxalic acid strips and essential oils in managing <i>Varroa destructor</i>. The experiment was conducted in 2022 at the experimental apiary in Debelec, part of the Institute of Animal Husbandry in Kostinbrod. Six experimental groups, each treated with a different preparation, were compared to a control group of untreated colonies. Treatments included Beevital Hiveclean (20 ml per colony), Varro Red (2 ml per frame), ammonium nitrate strips (1.3 mm), glycerin-oxalic acid strips (1.3 mm), and glycerin-oxalic acid strips of paper-cellulose (2.3 mm) or cellulose-cotton (2.3 mm). The control group remained untreated. The glycerin-oxalic acid strips made of cellulose and cotton (2.3 mm) showed the highest efficacy, reducing the mite infestation by 17.79% compared to the control. The glycerin-oxalic acid strips of paper-cellulose (2.3 mm) were also effective, achieving a 17.05% reduction in mite levels. These results provide valuable insights for beekeepers seeking alternative and sustainable methods for controlling <i>Varroa destructor</i> infestations.