The effect of worker loss on temporal caste structure in colonies of the honeybee (Apis mellifera L.)

The influence of colony population and brood area on worker longevity and foraging age were investigated in the honeybee, Apis mellifera L. Workers began foraging at younger ages and had shorter life-spans in colonies from which a majority of the worker population had been removed than in control colonies. This simulated loss in worker population was similar to naturally occurring events in feral colonies such as predation, swarming, nest damage, and (or) disease, as well as to some common management manipulations performed by beekeepers. Foraging age was negatively correlated with the area of eggs and larvae and was not correlated with pupal area. These results indicate that honeybee colonies are able to adjust temporal caste structure in response to rapid changes in colony conditions such as worker loss. The flexibility in temporal division of labor may be based on the inactive workers increasing their activity levels following stress by compressing the normal ontogeny of worker activities into a shorter time span.