ABSTRACT
The swarm-founding vespids, despite their comprising more than 24 genera and approximately one-third of the social species of wasps, have been little studied. Since C. Butler first described it in honey bees, polyethism in social insects has been the subject of uncounted studies. Worker polyethism in the swarm-founding wasps, however, has been touched on in only several studies, all of them unpublished dissertations. Plotting the frequency distribution of building and foraging tasks against age clearly reveals age polyethism with respect to the two task-sets. Polybia occidentalis exhibits clear-cut age polyethism. An age polyethism sequence in which the riskiest tasks are the last to be taken up yields the highest colony-wide life expectancy compared to other forms of division of labor. Analysis showed that only 36 and 13 percent of the temporal overlap in roles was due to overlap of performance by individuals; the remainder was due to the wide variation in the absolute age at which individuals made the transition.
