Abstract
Understanding the role of a species within an ecosystem requires information on their population ecology. In ants, population ecology is determined by how a reproductive division of labour is organised within a colony. Egg-laying has been shown to vary in polygynous colonies due to the range of reproductive strategies used by ant species. Differential egg-laying between queens – or reproductive skew – affects the growth of a colony, the genetic relatedness within a colony, and therefore how dominant a colony is in an ant community. Information on the reproductive division of labour is communicated chemically between ants via cuticular hydrocarbons (CHCs). Analyses of CHC profiles can therefore uncover information about the colony organisation and life history of a species. The aim of this research was to lay groundwork for understanding the diverse, facultative polygynous, native New Zealand ant Monomorium antarcticum and how its behavioural and chemical ecology relates to reproductive division of labour. This was performed by investigating M. antarcticum’s colony reproductive structure and how that is communicated with CHCs. In addition, a manual for rearing M. antarcticum in the laboratory long-term, and a protocol design for GC-MS analysis of M. antarcticum CHC profiles were included as tools for future research. It was found that M. antarcticum queens showed no signs of reproductive inhibition. Rather, M. antarcticum shared reproduction between queens in polygynous colonies, allowing for optimal colony growth, biomass, and genetic diversity in any environment. CHC analysis found that M. antarcticum colonies showed little CHC profile variation between different colonies and large CHC profile variation between reproductive castes, indicating that reproduction is very important for M. antarcticum’s population ecology. Most importantly, this study has found that CHC profile analysis has the potential to uncover valuable information about M. antarcticum’s life history and ecology around New Zealand.