Sublethal Effects and Associated Risks of Acaricides Used Against Varroa destructor in Honey Bee (Apis mellifera) Colonies

Beekeepers widely recognize Varroa destructor (Mesostigmata: Varroidae) as one of the most serious threats to honey bee (Apis mellifera) health. To control V. destructor, beekeepers routinely use chemical treatments that reduce mite populations, benefiting colonies. However, these treatments also expose honey bees to compounds that may cause unintended harm. Honey bees and V. destructor share biological structures that are targeted by acaricides. In this review, we describe the main modes of action of commonly used synthetic and natural chemicals and discuss differences between mites and honey bees that explain selectivity. In addition, exposure to non-lethal doses can potentially disrupt honey bee functions outside the treatment’s primary targets. Here, we synthesize current knowledge on the effects of V. destructor control chemicals on honey bee health at the molecular level, the individual level (including larvae, workers, queens, and drones), and the colony level. Unfortunately, not all tissues and colony functions have been studied for every compound. Therefore, this review also identifies knowledge gaps where the effects are still unknown. We believe that a better understanding of the effects of V. destructor treatments on honey bee colonies will help beekeepers manage these treatments more carefully, benefiting both beekeepers and honey bees.