Botanical solutions for managing mite and insect pests of honeybee colonies

Honeybees (Hymenoptera Apidae) and the beekeeping industry are increasingly threatened by parasitic mites such as Varroa destructor, Acarapis woodi, Tropilaelaps clareae, and T. mercedesae, as well as by insects like the wax moths Galleria mellonella and Achroia grisella and the small hive beetle Aethina tumida. While organic acids and thymol have been commercially available to manage such pests for almost 40 years, the widespread use of conventional acaricides and insecticides continues, making the development of biorational formulations crucial. This review focuses on various botanicals, including essential oils, plant extracts in organic and inorganic solvents, primary and secondary plant metabolites, vegetable oils, powders, plant smoke, propolis, and volatile organic compounds, that have been tested against hive-dwelling arthropod pests in both laboratory and field conditions. We listed the botanical families of the most employed species, plant parts extracted, and key phytochemicals identified. Additionally, we noted the methods and materials used in bioassays, the bioactivity (i.e. toxicity, repellence, attractiveness), and sub-lethal effects (e.g. prolonged or reduced development) on the pests, along with any data on the effects on honeybees, Apis cerana, and human cells. A brief overview of commercially available botanical-based formulations is also provided. Extracts from the neem tree (Azadirachta indica, Meliaceae), Lamiaceae herbs, and clove and eucalyptus (Myrtaceae) show results worthy of further investigation. Future challenges include developing nano/micro-encapsulated or emulsified formulations that are cost-effective, practical for hive use, and safe.