Honey bees are critical to world agriculture because of their role in crop pollination. Unfortunately, the sustainability of this bee is threatened by an increasing number of invasive pests, particularly the tracheal mite, varroa mite, and small hive beetle. Integrated pest management has not been well utilized by beekeepers, partly due to a lack of biological control agents. Microbial control strategies have been investigated for varroa mites using fungal pathogens, but have produced variable results. Difficulties have arisen because bees maintain hives at temperatures that are detrimental to the fungi, and the immature stages of the mites can avoid the fungi. It is also difficult to mass produce highly virulent and persistent fungal spores, and products are not available for use. One option to investigate further is the search for pathogens of the pests in their native range, as has been done in the introduction of biological control agents to field crop pests. Also, pests that have part of their life cycle outside the hive, such as small hive beetles, may be more amenable to biological control.