Abstract Jeanne 9514010 The number of workers in some social insect colonies can reach millions, yet they cooperate with one another and the colonies smoothly accomplish all their necessary tasks. It has recently been discovered for a tropical social wasp that the larger the colony, the greater its productive output per worker. This pattern contradicts previous understanding and has direct implications for the evolution of colony size. The purpose of the proposed research is to learn how the behavior of workers in large colonies is organized differently from that of small colonies and how these differences give rise to the differences in productivity. The research will be conducted on colonies in the field. New colonies are founded by swarms of workers and queens. Newly-founded colonies of different sizes will be made to repair nest damage to provide data on numbers of workers performing each type of work and their individual rates of work. Experimental manipulation of nest repair activity will be used to reveal the behavioral cues workers use to make decisions about whether to become active or idle. At the end of 25 days the colonies will be collected and the size measured (number of workers). The behavioral results will be correlated with colony size to determine how the changes in behavior at different colony size translate into per capita differences in output. The results of this study will explain the relationship between the behavior of group members and group size. The resulting knowledge of the underlying mechanisms will enhance our understanding of the evolution of large colony size in social insects and may provide insights into how human groups organize.
