Population dynamics and integrated pest management investigations of the fall armyworm (FAW) on maize conducted at the Faculty of Agriculture Teaching and Research farm, University of Port Harcourt, Rivers State Nigeria, made notable findings for the effective management of this notorious pest. This study involved 3 maize varieties namely Bende White (a local white variety), Oka (a local yellow maize) and Oba Super 98 (an improved white variety); two cropping patterns i.e. sole maize, and maize-yam intercrop; pheromonal trapping and pesticide (Kartodim 315EC). Pesticide applications were at 3 different phases (2WAP, 4WAP, and zero application as control, respectively). The pheromonal trap catches aided tracking of the pest’s population dynamics over the study duration showing the arrival times, build-up, peaks and falls. There was no significant difference in FAW populations between sole and intercrop plots; although 3 population peaks were found in maize-yam intercrop (at day 5, 7 and 17) against 2 peaks (day 4 and 15) in the sole maize. Oka variety showed significantly higher mean maize ear damages from FAW attacks (6.36 ± 2.45), compared to Bende (5.71 ± 2.87) and Oba 98 (4.77 ± 2.64) (p < 0.05), implying that Oba 98 may be the best maize variety for cultivation in this locality.