Social structure and the determinants of queen status in the primitively eusocial wasp Ropalidia cyathiformis

Abstract

Primitively eusocial wasps are of great interest to students of sociobiology because of the flexibility in social roles that an individual can adopt. This flexibility can be rather spectacularly illustrated using the common Indian spe.cies Ropalidia cyathiformis (Gadagkar and Joshi 1985). Here females eclosing on a nest have several options open to them. Some females leave the parent nest to start new, baplometric nests. Others also leave to found new nests, but pleometrotically i.e., they leave along with some workers. Yet other females stay on at the parent nest and eventually challenge the queen and take over the nest. Finally of course some females stay on at the parent nest and remain as sterile workers throughout their life. Prompted by the presence of such diverse reproductive strategies we have made a quantitative study of the behaviour of individually identified wasps. Even among the females staying back at the parent nest, multivariate statistical analysis of time activity budgets of individually identified wasps has revealed the presence of a behavioural caste differentiation into Sitters, Fighters and Foragers (Gadagkar and Joshi 1984). Here I report experiments designed to understand the biological and evolutionary significance of tryese behavioural castes.