The fall armyworm (FAW) Spodoptera frugiperda J. E. Smith is the most noxious insect to maize and sorghum in the state of Colima, Mexico. In this work, two maize landraces (‘blanco’ and ‘aperlado’), native to Colima, were grown in Tecomán, Colima, to determine the FAW population behaviour under natural conditions. The spatial distribution of the FAW larvae was random, and natural infestations were strongly associated with the maize phenological stages. The relationship between FAW and plant phenology was explained by non-linear regression models.
