Social insects employ multiple strategies to divide labor within the worker caste, including temporal or morphological task allocation. Temporal task allocation occurs when workers perform specific jobs as they age, while morphological task allocation occurs when workers are physiologically specialized to perform a specific job. Flying social insects, such as wasps and bees, commonly evolved temporal task allocation however the first examples of morphologically distinct guards have been found in stingless bees. The frequency of morphological task allocation in this group is currently unknown but previous work suggests in may be widespread across several genera.
Results/Conclusions
We assessed the morphology of worker bees of Melipona beecheii beecheii, a stingless bee used for meliponiculture in Latin America. Guard and forager bees were collected from three sites in Cuba and ten morphological measurements were taken per individual. There is variation in the worker caste between guards and foragers; furthermore, guard morphology varies between colonies. The presence of morphologically distinct guards may represent an evolutionary need for increased protection from predators and parasites.