Quantitative ethology of social wasps: time-activity budgets and caste differentiation in Ropalidia marginata (Lep.) (Hymenoptera: Vespidae)

Abstract

Time-activity budgets of several individually identified members of Ropalidia marginata colonies have been constructed with the aim of studying caste differentiation in social wasps that show no morphological differences between individuals. Analysis of these data by multivariate statistical techniques including principal components analysis and hierarchical cluster analysis has demonstrated the presence of three different behavioural castes which we have named Sitters, Fighters and Foragers. The Sitters in a colony consist of the queen and also some non-egg-laying individuals. The Fighters are non-egg-layers that show alarm reactions in response to disturbances and also fight with other individuals on the nest to a very large extent. The Foragers are also non-egg-layers and they spend a large proportion of their time making trips to places away from the nest to collect food, building material etc.