TEMPORAL DIVISION-OF-LABOR IN THE HONEY-BEE, APIS-MELLIFERA - A DEVELOPMENTAL PROCESS OR THE RESULT OF ENVIRONMENTAL-INFLUENCES

The association between the age of a worker honey bee (Apis mellifera) and her behavior is generally believed to be the result of an innate developmental process. An alternative model, called foraging for work, explains this association as being due to old and young workers being in functionally different parts of the nest as a result of their having been in the nest for different lengths of time. Previous studies also raise questions about the developmental-process model because they relied on sequential observations of workers from one age group, thereby confounding age and environmental effects, which also affect behavior. Environmental effects were controlled by making concurrent observations of workers from four age groups introduced to a colony at 6-day intervals. These groups behaved differently from one another, even though they were present in the same environment, thereby demonstrating age effects independent of environmental effects. The foraging-for-work model was evaluated by comparing workers from three age groups introduced to the colony on the same day. These groups also behaved differently, showing that the association between age and behavior is not simply an epiphenomenon resulting from old and young workers having been in the nest for different lengths of time.