Age Is More Important Than Size in Determining Dominance Among Workers in the Primitively Eusocial Wasp, Polistes Instabilis

In primitively eusocial wasps, dominance hierarchies predict which female will become queen when the original queen is removed. At each of 3 latitudes spanning a range from temperate sites to tropical ones, an older, dominant, worker of the primitively social wasp, P. instabilis, became the replacement queen. Thus, even in the tropics, this species follows a temperate queen replacement pattern rather than the standard tropical pattern in which young non-foragers have the highest rank and replace the queen. Old individuals are dominant even though they are often smaller than their subordinates. These results are surprising because large size increases the chance of winning fights for queenship among Polistes females in other circumstances. Age-based dominance hierarchies may be stable in Polistes because colony members resist larger individuals' attempts to win high dominance rank by fighting.