Evaluating the effectiveness of a commonly used protein source on honey bee (Apis mellifera) colony growth during the summer dearth

In recent years, beekeepers in the USA have been faced with high annual loss of managed honey bees (Apis mellifera L.) colonies. The Bee Informed Partnership recently reported that surveyed beekeepers lost 32% of their colonies in summer 2019, the highest loss rate reported during this period to date. Poor nutrition is suspected to be a major contributor to summer colony losses, as many regions across the country experience resource dearth. To supplement bee nutrition, beekeepers commonly provide their colonies with pollen substitutes commonly composed of alternative protein sources such as whey, eggs, yeast, soy, or lentils. In this experiment, we set out to test if a protein source commonly used as a summer supplement can be as beneficial to colony health and maintenance as natural pollen. We established 15 honey bee colonies of similar size during the summer resource dearth (n=5 per treatment) and measured food consumption and colony growth metrics (population, brood, and stored resources) when the bees were given 1) no supplement (negative control); 2) a soy-based pollen substitute; or 3) natural pollen (positive control). We expected colonies receiving the pollen supplement patties to consume the highest amount of food, experience the greatest colony growth, and contain the most physiologically fit workers compared to colonies that received either the soy-based diets or no supplement at all. The results from this ongoing project will help inform beekeepers about how to better regulate nutrition in their colonies to improve their health and productivity during the summer dearth period.