The role of botanical treatments used in apiculture to control arthropod pests

Among pests of bees and beehives, arthropods make up a large and important group. Mites like Varroa destructor , Acarapis woodi , or Tropilaelaps spp., beetles ( Aethina tumida , Oplostomus spp.), and lepidopterans ( Galleria mellonella , Achroia grisella ) decrease honey bee population and vitality, with subsequent significant colony production losses. Synthetic chemicals have been traditionally used to protect honey bee colonies from pests’ infestations but they have often been of poor selectivity, consequent high toxicity to bees and humans, and resistance development by the targeted apiary pests. The current European policy encourages the usage of eco-friendly methods to combat bee pests and the international research highlights plant secondary metabolites as candidate alternatives of significance. In this review, we argue the potential of plant-derived substances in the protection of the bee colonies against their arthropod pests. The before mentioned major apiary arthropods are briefly described followed by the recent reports on the botanical extracts and notable constituent compounds exhibiting activity against them. We discuss the different ways the essential oils are reported to be applied to the bee or the apiary, along with the importance of the application method to the exhibited efficacy. We designate synergism issues of blends, attractants, and repellency cases, as well as selectivity and mode of action as reported for bees or insect pests.