The role of queens in colonies of the swarm-founding wasp Parachartergus colobopterus

Social insect queens reproduce while workers generally do not. Queens may a lso have other behavioural roles in the colony. In small, independent-found ing colonies of social wasps, the dominant queen physically enforces her in terests over those of the workers and serves as a pacemaker of the colony, stimulating workers to forage and engage in other tasks. By contrast, in la rge-colony, swarm-founding wasps, the collective interests of the workers a re fulfilled in sex allocation and production of males, whether or not they coincide with the interests of the queens. The behavioural role of the que ens in such species has not been extensively studied. We investigated the r ole of the queens both in regulating worker activity and in reducing the nu mbers of reproductively active queens in the swarm-founding epiponine wasp Parachartergus colobopterus. We found no evidence that queens regulate work er activity, as they were rarely involved in any interactions. Worker activ ity may be self-organized, without centralized active control by anyone. Fu rthermore, we found no evidence that the reduction in queen number characte ristic of this tribe of wasps occurs in response to aggression among queens . The reduction in queen number may be a result of worker treatment of quee ns, although worker discrimination against some queens was not obvious in o ur data. (C) 2000 The Association for the Study of Animal Behaviour.