A survey was conducted on Banks Peninsula and the Port Hills in Canterbury, to detennine the present distribution and the potential for further spread of the subterranean pasture pest Adoryphorus couloni. It was found that A. couloni had spread from previous known infestations and that further spread was likely. In particular, it was found that several sites in Gebbies Valley and near McQueens Pass had been colonized by A. couloni and that invasion of the Canterbury Plains in the future is a distinct possibility. The rate of spread of A. couloni on Banks Peninsula and the Port Hills was estimated using a simple dispersal model. Natural ispersal was predicted to occur at a rate of 1.136 km/year and it is possible that human-assisted dispersal could have aided this species' spread. A review of the relevant literature identified environmental conditions preferred by the species and potential methods of control.