Data from: Soldiers in a stingless bee: work rate and task repertoire suggest they are an elite force

The differentiation of workers into different morphological sub-castes
(e.g. soldiers) represents an important evolutionary transition and is
thought to improve division of labor in social insects. Soldiers occur in
many ant and termite species where they make up a small proportion of the
workforce. A common assumption of worker caste evolution is that soldiers
are behavioral specialists. Here, we report the first test of the “rare
specialist” hypothesis in a eusocial bee. Colonies of the stingless bee
Tetragonisca angustula are defended by a small group of morphologically
differentiated soldiers. Contrary to the “rare-specialist” hypothesis, we
found that soldiers worked more (+34-41%) and performed a greater variety
of tasks (+23-34%) than other workers, particularly early in life. Our
results suggest a “rare elite” function of soldiers in T. angustula, i.e.
they perform a disproportionately large amount of the work. Division of
labor was based on a combination of temporal and physical castes, but
soldiers transitioned faster from one task to the next. We discuss why the
“rare specialist” assumption might not hold in species with a moderate
degree of worker differentiation.