Caste in the swarming wasps: Queenless societies in highly social insects

Morphometric data for 30 species of swarming wasps (Vespidae: Polistinae: Epiponini) are presented, representing all currently recognized genera. Data are coded according to whether females that were shown by dissection to be egglayers are larger, the same, or smaller for each dimension than non-egglayers. These data are analyzed in a phylogenetic framework with primitively social Polistes and Mischocyttarus as outgroups. Representative measures are illustrated to show that most genera of Epiponini appear to have ancestry in a lineage that has no queen caste comparable to either the primitively social outgroups, or the more derived species of the tribe. This analysis indicates that a conspiracy of workers that operates without a queen characterizes the societies of many Epiponini or their recent ancestors.