VARIATION IN PERCEPTION OF TASK INITIATION AND COMPLETION BETWEEN TEMNOTHORAX RUGATUL8US NESTMATES DRIVES DIVISION OF LABOR

Abstract

Division of labor is one of the defining characteristics of social insect societies. It is thought that division of labor arises through simple logical rules and requires only that workers respond to environmental stimuli they encounter. It has been proposed that the response threshold is one of the primary rules that drives division of labor. We test this hypothesis by measuring response thresholds in the ant species Temnothorax rugatulus to different task-associated stimuli and see whether or not they can predict which tasks the ant takes on in the colony. We found that the response threshold hypothesis successfully predicts the relationship between the sensitivity to task-associated stimuli and performance of the task itself for one task, but it fails at predicting the relationship of the other task. In fact, the results were the opposite of what the response threshold predicted, suggesting that there may exist an alternative rule that functions in the opposite direction of the response threshold and yet may also be capable of allocating tasks. Here we coin the term ‘satisfaction threshold’ as a name for this alternative mechanism.