Divergence in Time Apportionments of Tongue Protraction and Retraction Phases for Feeding Honey Bee Drones and Workers

Abstract

Honey bees have three castes, drones, workers, and queens, that accomplish different tasks. In this research, we revealed the divergence in feeding behavior of drones and workers by experimental and theoretical techniques from the perspective of tongue kinematics. We observed the feeding cycles from living drones and workers of Apis mellifera ligustica and introduced a fluid transport model for computing the energy consumption during nectar feeding. We derived the theoretically-optimal time apportionment ratios (TARs) in the tongue protraction and retraction phases of drones and workers under the objective function of maximizing the efficiency of nectar uptake. By comparing the theoretically-optimal TARs with the real ones, we drew a conclusion that there is a dichotomy in nectar-feeding behavior between drones and workers. The actual TAR of drones is not consistent with the theoretically-optimal TAR while the actual TAR of workers is. This dichotomy may be caused by caste-related labor and environmental constraints.