Effects of various fall feeding sugar sources on survival, health, and productivity of honey bee colonies (Apis mellifera L.)

Abstract

In Canada, beekeepers must supplement their colonies with sugar in the fall to ensure survival during winter, when floral resources are absent.
Sucrose syrup is the predominant choice due to its high availability, chemical stability, and ease of use. However, upcoming revisions to Canada’s organic standards will prohibit the use of conventional sugar syrup, necessitating a shift toward honey or organic sugar syrup as overwintering resources. The implications of this transition on colony survival, development, productivity, and pathogen prevalence remain insufficiently characterized. This study evaluated honey bee (Apis mellifera L.) colonies fed with either conventional sugar syrup, organic sugar syrup, summer honey, or fall honey. Key parameters assessed included winter survival, colony development, honey production, and pathogen development (Varroa destructor, Nosema spp., and six viruses).
Results indicate that organic sugar syrup, summer honey, and fall honey are viable alternatives to conventional sugar syrup for overwintering. However, precise colony weight management following fall feeding is critical to prevent starvation. In most cases, a minimum of nine honey frames per colony housed in a Langstroth single-brood chamber or four frames supplemented with 12L of organic sugar syrup supported successful overwintering, although adjustments may be required depending on colony size and winter severity.
No statistically significant differences were observed in brood and bee population development, honey production, or pathogen development across feeding treatments. These findings suggest that while organic beekeepers can effectively overwinter colonies using alternative carbohydrate sources honeybased feeding warrant careful consideration.