Biocontrol effect of Fomes fomentarius mushroom against Varroa destructor

Varroa destructor is the most important pest of western honeybees. In recent decades, numerous methods have been developed to control this mite. The most common and effective method is the use of chemicals. However, they pose different threats to bees and their products. Therefore, non-chemical methods should also be developed. This study investigated the efficacy of different formulations of the fungus Fomes fomentarius in controlling the Varroa mite. The results showed that the efficacy of smoke, dribble, and gel treatments was 63.80%, 69.17%, and 72.13%, respectively. These treatment methods had no negative effects on the number of sealed brood areas and bee-covered frames (P > 0.001). Burning the fungus with the beekeeper’s smoker led to a rapid death of mites on adult bees. The gel treatment had an extended-release effect. This mushroom and its formulations are recommended for mite control. The efficacy of various mushrooms against Nosema ceranae and deformed wing virus has been investigated by other researchers. However, as there is no source in the literature for the use of fungi to control the Varroa mite, we believe this study is the first.