Social organisation in the Indian wasp Ropalidia cyathiformis (Fab.) (Hymenoptera: Vespidae)

Abstract

Multivariate analysis of time-activity budgets of several individually marked adults of the primitively eusocial Indian wasp Ropalidia cyathiformis shows the existence of three behavioural clusters (or castes) which are called Fighters, Sitters and Foragers, after their most distinguishing features. The principal egg layers who are also the most dominant individuals are the Fighters. The Sitters are idlers who are speculated to be'hopeful queens' and the foragers are the principal worker force of the nests. Such a behavioural differentiation does not normally appear to change drastically with age of the animal. Nor does it change when an individual leaves a nest and founds or joins a different nest. It probably could however change in response to major perturbations such as death of the queen. Males as a class do not form a separate cluster distinct from the females but may either be Sitters or Foragers. Comparison of these results with those of R. marginata, a related social wasp, whose queens are Sitters, suggests that there is a higher level of reproductive competition in R. cyathiformis.