<p>The fall armyworm (<i>Spodoptera frugiperda</i> (J.E. Smith)) is a serious pest of maize in Ethiopia. Understanding fluctuations in moth population and oviposition is crucial for predicting peak periods of crop damage. This study aimed to investigate the relationship between the number of egg masses and the timing of maize planting and growth stages. Eight consecutive sowings of maize were conducted in fifteen-day intervals at Dalbo and Hawassa, Ethiopia, in 2022 and 2023. Moth population was monitored using pheromone traps, and egg masses were recorded weekly. The highest number of moths/trap was 203 and 641, whereas 10 and 12 egg masses/100 plants were observed at Dalbo and Hawassa, respectively, in July 2023. During both cropping seasons, the lowest total number of egg masses was recorded from early-sown maize in March (Dalbo) (&lt; 22/100 plants) and April (Hawassa) (&lt; 31/100 plants); while the late plantings had the highest (&gt; 75/100 plants). The early and mid-whorl stages had the highest weekly egg mass counts (12–18/100 plants) compared to the reproductive growth stages (1–4 egg masses/100 plants) of maize. The majority (&gt; 82.5%) of egg masses were laid on the underside of the leaf, with the proportion laid on top of the leaf increasing during the 9–16&#xa0;weeks after emergence. Planting early allows farmers to avoid the peak FAW moth population that typically occurs in July. This strategy can be a key component of integrated FAW management because it creates a phenological asynchrony between the young maize plants preferred for oviposition and the pest's peak population.</p>