Raising Male Drones Affects Honey Bee (Apis mellifera) Foraging Behavior

Globally, honey bees (Apis mellifera) are a vital commercial pollinator, contributing to food security and economies. One of the most pressing threats honey bees face is the parasitic mite Varroa destructor, which weakens bees and spreads pathogens. There are many chemicals for mitigating mite population growth, however, many have unintended consequences on the bees themselves and/or hive products. A popular, chemical-free method of combatting Varroa is drone comb removal, which provides the colonies with the space to raise larger, mite-preferred male bees, or drones. While this method has been shown to reduce colony-level mite numbers, it may add another, unanticipated, layer of colony-level stress; drones are nutritionally expensive to raise, particularly in protein. We examined how investment in protein-rich drones affects the in-hive worker population and colony-level foraging behavior. Raising drones did not affect the in-hive worker population, however, it did lead to a larger proportion of foragers returning to the hive with protein-rich pollen. The crude protein content (%) of pollen brought back to the hive remained the same among treatments suggesting that colonies raising drones allocated more energy to pollen foraging, but did not seem to seek resources with a higher crude protein content. This could be due to a lack of discrimination of pollen nutritional quality by foragers and/or availability of diverse floral resources. Here, we present an applied system for future studies investigating integrated pest management in honey bee colonies, and a basic system for understanding how shifts in social insect sex ratios affect colony-level processes such as foraging and overall productivity.