Comparison of nectar foraging efficiency in the Cape honeybee, <i>Apis mellifera capensis</i> Escholtz, and the African honeybee, <i>Apis mellifera adansonii</i> Latreille, in the western Cape Province

Abstract

Colonies of African honeybees have significantly (p < 0,05) more unsuccessful foragers than colonies of Cape honeybees, while Cape colonies have significantly (p < 0,02) more foragers returning with nectar. No significant difference was observed in the numbers of returning pollen gatherers or foragers carrying both pollen and nectar. Nectar foragers of Cape honeybees return with significantly larger volumes of nectar (p < 0,001) than nectar foragers of the African race. The nectar concentrations showed no significant difference. No significant difference was observed in the mass of pollen carried by returning pollen gatherers. The Cape honeybee foragers returning with both pollen and nectar had significantly larger volumes (p < 0,05) of nectar and larger loads of pollen (p < 0,05). The nectar concentrations showed no significant difference. Colonies of African honeybees showed a mean mass loss of 3,37 kg while colonies of Cape honeybees showed a mean mass gain of 1,88 kg over the experimental period of 78 days. The hypothesis has been advanced that these differences reflect adaptations in the Cape honeybee to a more temperate environment. It is also suggested that the distribution of the African honeybee in southern Africa and South America is limited to an inability to provision the nest with sufficient energy to withstand the temperate winter conditions prevailing in these latitudes.