Abstract:
Fall armyworm (FAW), scientifically known as Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an important polyphagous pest that causes significant yield losses in various crop plants. The critical role of ambient temperatures in shaping the biology, distribution and population dynamics of FAW highlights the importance of temperature in its life cycle. The aim of this study was to evaluate the effects of different temperature conditions on the growth and development of FAW. The FAW larvae were collected from infested fields and maintained under three different temperature regimes: 25 °C (T25), 30 °C (T30), and 35 °C (T35), all within a controlled photoperiod of 12:12 h, maintained in an incubators. Comprehensive life and fertility tables were created using growth parameters. Analysis of variance revealed statistically significant differences (p < 0.05) in the mean duration of each life stage across the different temperature conditions. Of note, the adult stage had a cumulative mortality of 95% at T35, 61% at T30, and 64% at T25. The net reproductive rate (Ro) was quantified as 132.17, while the average generation time (Tc) was the shortest at T30 (32.31). The daily finite rate of increase (λ) was 1.1702 females per female per day, with a population doubling time of 3.004 days. In parallel, the intrinsic rate of natural increase (rm) was recorded as 0.1511 females per female per day. Importantly, the hypothetical female population in the F2 generation showed a significant increase at T30 (17468.20). In conclusion, the results clearly highlight the superior influence of a temperature of 30 °C (T30) on the growth and development of FAW compared to the other temperature conditions tested. These results are of significant practical importance in the context of pest control modeling and predictive forecasting.
