The behavioural sequence of courtship and mating of Sesamia nonagrioides Lefèbvre males and females in laboratorycages is described. The attractant capacity of both sexes was studied by tethering males or females. The courtshipand mating sequence of tethered females was the same as untethered ones, but tethered males were absolutely inactive.Age (1 day versus 2 days) did not affect the mating rate. Differences in calling time onset and first calling agewere found between north-eastern Spanish and Greek populations. The role of hair pencils in courtship flight is discussed,rejecting that they stimulate calling behaviour of females or that they attract females. The influence of adultpopulation density was studied in laboratory and field tests, and was found to have no effect on the mating rate in thecontrols. However, moth density influenced mating rates where mating disruption treatments were applied. Several consequences for investigations into pheromone composition and its use in monitoring and population control are reported in the discussion.