A Tale of Two Wasps and Why We Should Listen to It

Hymenopterans present a fascinating diversity of social organisation, from solitary individuals building unprotected nests like the potter wasps to the very complex and highly organised societies of honey bees and most ants. A large number of paper wasps have intermediate levels of social complexity, and are designated as primitively eusocial, as they lack a morphologically distinct queen caste. Nevertheless, they have behaviourally distinct queens and workers, and are excellent model systems for understanding the intermediate steps in the process of social evolution, from solitary to complex social systems. Of the many facets of social organisation, the regulation of work in the colony and the establishment and maintenance of reproductive monopoly are the two aspects that are the most intriguing to sociobiologists. Ropalidia marginata and Ropalidia cyathiformis are two species of closely related paper wasps that are found in peninsular India, in the same habitat, and have much overlap in their ecology and ethology. However, this duo is also an interesting study in contrast in several aspects of social behaviour. Hence, together, they present an excellent opportunity for comparative study, to identify crucial steps in social evolution. In this article, we provide an overview of a series of studies that have been conducted by Prof. Raghavendra Gadagkar and his team over 4 decades at the Indian Institute of Science, Bengaluru, to unravel the evolutionary tale that these two species together elucidate.