Grant: Discovery Grants Program - Individual

The organization of individual insects into cooperatively complex groups represents one of the major transitions of life on earth. However, it also comprises one of the greatest challenges for Darwin's theory of evolution. My research program investigates the evolution of chemical detection of invaders and chemical communication (pheromones) within insect social colonies. The importance of chemical signaling to the release of social behaviour has been demonstrated in social insects, but its potential evolutionary role has not been shown. Here, I propose to investigate the role of pheromones in the evolutionary trajectory that has led to insect sociality and to address two major challenges facing evolutionary biology: why does social behaviour first evolve and, once it has evolved, how can it be elaborated into complex systems of organization? Most research on social insect communication has focused on these insect groups: the bees, ants, wasps and termites. The communication mechanisms in these groups likely evolved many tens of millions of years ago, so that early steps in the development of communication are likely to have been overwritten by evolutionary elaboration. To elucidate the role of communication in the evolution of sociality it is essential to target relatively recent evolutionary origins; such a worker caste has evolved relatively recently (approx. 6 million years ago) within the thrips insect group and the forms of communication in this suite of species likely reflect the very first steps in colonial organization. The focal organisms for this research will be the gall-inducing thrips and their specialist invaders on Acacia plants. Thrips provide an alternative model for understanding social evolution, and have already provided major and different insights to studies of the 'traditional' social groups. Chemical communication in social thrips colonies has not yet been considered due to the paucity of life-history details that have only recently been uncovered. This program will place Canada at the forefront of evolutionary and chemical ecology, as well as building on Canada's existing excellence in socio-biology.