Modern molecular genetic techniques are used to examine Helicove1pa armigera for variation amongst individuals from different geographical locations around Australia. The prime objective has been to assess population structure: to find regionally diagnostic variation that will allow us, indirectly, to estimate the magnitude, direction and timing of movement patterns of these pest moths. This infonnation would be valuable to the ecologists in their efforts to better predict moth movement into cropping areas and hence improve control. It would also help in planning strategies to minimise the spread of insecticide resistance and thus benefit the Cotton Industry.