Honeybee rebel workers preferentially respond to high concentrations of sucrose

The honeybee is one of several eusocial species with a complex set of anatomical, physiological, and behavioural traits that are correlated with foraging preferences. Sensory sensitivity to sucrose is associated with the foraging preferences of workers, with individuals that are less sensitive to sugar preferring to forage for nectar and those that are highly sensitive to sucrose preferring to forage for pollen. In this study, we test this hypothesis by comparing the sucrose responsiveness of genetically similar normal and rebel honeybee workers, which present different foraging preferences. We found that rebels, which prefer to forage for nectar and have a higher reproductive potential than normal workers, are characterised by sucrose sensitivity that is lower than that of normal workers. Moreover, we show that in both rebel and normal workers, sensitivity to sugar in nectar is lower in workers when their ovaries contain more ovarioles. The results confirm the prediction that bees present a foraging preference depending on their response thresholds to sucrose in solution. However, compared with previous studies, our investigation does not support the assumption that reproductive workers are more sensitive to sucrose concentrations in nectar.