Dominance behaviour and division of labour in the tropical primitively eusocial wasp Ropalidia cyathiformis

Abstract

Primitively eusocial insects exhibit reproductive division of labour such that one or a small number of individuals monopolize reproduction while the remaining function as non-reproductive workers. They also exhibit non-reproductive division of labour such that some workers primarily perform the extra-nidal tasks of foraging, while others primarily perform the intra-nidal tasks of feeding larvae, building the nest and other nest maintenance activities. In some species, queens regulate both reproductive as well as non-reproductive division of labour by means of their dominance behavior toward the workers. Here we show that in the primitively eusocial species R. cyathiformis, (1) the queen shows significantly more aggression towards the potential queen (PQ) than to the rest of the workers; (2) the PQ shows significantly more aggression towards the workers than they show to each other; (3) the activities of the workers such as bringing food and feeding the larvae continue unabated in the absence of the queen; (4) the amount of dominance received by a worker does not predict her rate of foraging; (5) there is a positive correlation between workers’ rates of bringing food and the rates at which they themselves feed the larvae. We suggest that while queen (along with PQ) regulates reproductive division of labour, dominance behavior is not used to regulate the non-reproductive activities of the workers such as bringing food and feeding the larvae; these are self-regulated by individual workers by themselves.