Pre-almond supplemental forage improves colony survival and alters queen pheromone signaling in overwintering honey bee colonies

Abstract

Supplemental forage can be used to provide nutrition to bees during winter dearth. We examined the effects of supplemental forage on colony performance, colony survival, worker quality, and queen pheromone signaling in Nosema ceranae-infected overwintering colonies. Colonies were either supplemented with rapini or left unsupplemented for 1 month before almond pollination. Unsupplemented colonies experienced higher mortality than supplemented colonies. Supplemental forage did not affect colony performance, worker mass, or hypopharyngeal gland protein content. However, supplemented queens released more of three queen QMP and QRP compounds (4-hydroxy-3-methoxyphenylethanol, methyl oleate, and 1-hexadecanol) that promote queen care among workers. In addition, colonies that survived almond pollination thermoregulated their hives more than colonies that failed. Supplemental forage may prepare overwintering colonies for the stresses of early spring pollination.