Individual variation in queen morphology and behavior predicts colony performance in the wild

Abstract

The founders of a social group or colony have the potential to greatly influence the success or failure of the societies that they initiate. Whether through their genetic contribution, or through behavioral maternal effects related to temperament, resource acquisition, or brood care, the traits of founders deserve special consideration. The queens of many social insects are ideally suited to address questions relating to the importance of founder traits due to her solitary involvement in performing a multitude of tasks necessary to produce a functioning colony. While it has been suggested that a queen’s behavioral phenotype might contribute to differences in colony success, no study has yet demonstrated these links in situ. Here, we use the singly founding (haplometrotic) paper wasp Polistes metricus to examine whether queen personality, measured shortly after colony founding (pre-emergent phase), and morphology, can predict colony size (a proxy for queen fitness) and parasite load in the wild. We found that larger and bolder queens gave rise to larger colonies than smaller and shyer queens, and there was no relationship between queen personality and parasite load. Differences in queen traits therefore appear to be a major determinant of colony success under field conditions. In social species, the personality composition of groups has been shown to be a large determinant of group behavior, which in turn can determine group performance and survival. In this study, we explore the degree to which the behavioral tendencies of key group members—wasp queens—influence the performance of their descendant societies. We tested the behavioral tendencies and morphology of Polistes metricus paper wasp queens in the early spring, placed them back in the field in nest boxes, and recorded each nest’s cell count at the end of the season—a reliable proxy for queen fitness. We found that larger and bolder queens gave rise to larger descendant colonies on average than their smaller, shyer counterparts. Individual variation in queen traits therefore appears to be a determinant of colony success under field conditions.