Division of labor among a cohort of young individuals in a primitively eusocial wasp

Abstract

Age polyethism has recently been demonstrated in the primitively eusocial wasp Ropalidia marginata, and it has been shown that workers allocate tasks based more on their relative age rather than on their absolute age, thus providing flexibility to division of labor. The flexibility of division of labor and the respective roles of absolute and relative ages is further evaluated here by creating colonies of only young individuals (young-cohort colonies). The results show that workers in young-cohort colonies can forage at an earlier age, in larger numbers and with a higher probability and frequency. This confirms that division of labor in the colony can indeed be independent of absolute age. The results also show that relative age governs the probability of task performance while absolute age governs the frequency of task performance. The constraints posed by absolute age in the organization of work in an insect colony and the flexibility lent to it by relative age are discussed.