Spodoptera frugiperda J.E. SMITH (Lepidoptera: Noctuidae) on Local Rice Variety Kuriak Kusuik from West Sumatera Indonesia: Demographic Statistics and Biology

Spodoptera frugiperda (Fall Armyworm/FAW) is a polyphagous invasive pest that has spread across various regions in Indonesia, posing a serious threat to staple crops, especially maize. However, the potential adaptation of FAW to rice plants, particularly local varieties from West Sumatra such as Kuriak Kusuik, has not been previously reported. This study aimed to examine the biological and demographic characteristics of S. frugiperda when fed with the Kuriak Kusuik rice variety. The results showed that FAW was able to complete its life cycle on this rice variety, with an average lifespan of 41.56 days. The survivorship curve was classified as Type III, characterized by high mortality in the early life stages. The net reproductive rate (Ro) was 46.75 individuals per generation, while the gross reproductive rate (GRR) reached 349 individuals. The intrinsic rate of increase (rm) was 0.10 individuals per female per day, with an average generation time (T) of 38.12 days and a population doubling time (DT) of 6.87 days. These findings indicate that although rice is not its primary host, S. frugiperda is capable of adapting and reproducing on the Kuriak Kusuik rice variety, suggesting that it may pose a potential threat to rice production systems in Indonesia.