Worker size in honeybees and its relationship with season and foraging distance

Abstract

Workers in many eusocial insect species show considerable size variation within a colony. Honeybees (Apis mellifera) vary little in size compared to other eusocial bee species, but there is evidence for a link between worker size and behaviour. In this study, we investigated how size variation and the average size of honeybee foragers change during a foraging season. We also tested the influence of colony weight and swarming on worker size. Finally, by analysing waggle dances, we tested if forager size is linked to foraging distance, between and within colonies. We found that the size of foragers significantly increases over the foraging season. Swarming did not appear to affect worker size, but colony size was overall positively linked to wing length and leg width. However, we did not find a relationship between foraging distance and forager size. We discuss how the constant size of brood cells and an efficient communication between foragers could lead to a narrower size range.