Fall armyworm Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) (FAW) is one of the devastating polyphagous pests having a wide range of host plants that contribute substantial losses to crop cultivation. For such pests, temperatures exert a significant impact on biology, distribution, and abundance. Hence the present study was executed with the aims of evaluating the effects of different temperatures on the growth and development of fall armyworm. FAW larvae collected from the infested field and were reared in three different temperatures regimes viz. 25±1°C (T25), 30±1°C (T30) and 35 ±1°C (T35) incubator provided with 12:12 photo period. Life table and fecundity tables were calculated using growth parameters. The results indicated that the mean duration of each stage of lifecycle at three different temperatures were significantly different from each other. The accumulated mortality at the adult stage was 95%, 61% and 64% at T35, T30 and T25 respectively. The net reproductive rate (Ro) was 132.17, the average period of generation time (Tc) was less in T30 (32.31) with the daily finite rate of increase in number (λ) was 1.1702 females/female/day and a population doubling time of 3.004 days. Similarly, the intrinsic rate of natural increase in number (rm) was 0.1511 females/female/ day and hypothetical female population in the F2 generation was found to be higher at T30 (17468.20) thus the results indicated that T30 favors the growth and development of FAW compared to the other tested temperatures. Our findings could be useful for the implication in pest management and forecasting.

Maize germplasm has greater latent potential to address the global food and feed crisis because of its high radiation, water and nutrient efficiencies. Photosynthetic and canopy architectural traits in maize are important in determining yield. The present study aimed to screen a subset of local maize accessions in Sri Lanka to evaluate their photosynthetic, biomass and yield related traits and to identify resource efficient germplasm. Experiments were carried out in the Ampara district of Sri Lanka. Eight maize accessions viz; SEU2, SEU6, SEU9, SEU10, SEU14, SEU15, SEU17 and SEU17 and two elite F1 cultivars (cv. Pacific-999 and cv. Bhadra) were analyzed under field conditions. Our results showed that maize genotypes produced a lower leaf area index (LAI) at the third and tenth week after field planting (WAP). However, the LAI was significantly increased in six WAP by Pacific-999, SEU2, SEU9, and SEU15. A similar trend was observed for percentage of light interception at three WAP (47%), six WAP (>64%), and decreased at 10 WAP. In addition, LAI maximum values were between 3.0 and 3.5, allowing 80% of the incident light to be intercepted by maize canopies. The estimated light extinction coefficient (k) remained lower (<0.5), suggesting that maize leaves are eractophilic canopies. Although fractional interception (f) varies, SEU2 and SEU9 had the highest values (0.57), and quantum yields of PSII (>0.73) in dark-adapted leaves. In addition, Pacific-999, SEU2, SEU9, and SEU17 had significantly higher rates of photosynthesis with minimal stomatal conductance and transpiration rates. As a result, they outperformed the control plants in terms of biomass, cob weight and grain yield. This suggests that native maize germplasm could be introduced as novel, less resource-intensive cultivars to sustain global food security.